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pcie stalled using rtl8192ce (default wifi card) #4

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waby38b opened this issue Mar 30, 2023 · 4 comments
Open

pcie stalled using rtl8192ce (default wifi card) #4

waby38b opened this issue Mar 30, 2023 · 4 comments
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@waby38b
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waby38b commented Mar 30, 2023

pcie Wifi card included in 4kopen box is a rtl8192ce

Seem, that our DWC pcie driver generate randomly some HANG
Here some logs related to this HANG (stacktrace)
=> seem related to interrupt

[  184.243426] rcu: INFO: rcu_sched self-detected stall on CPU
[  184.249008] rcu: 	0-....: (8405 ticks this GP) idle=df74/1/0x40000002 softirq=3607/3607 fqs=2972
[  184.257790] 	(t=8407 jiffies g=6613 q=56899 ncpus=4)
[  184.257803] CPU: 0 PID: 1059 Comm: ifconfig Not tainted 6.2.7 #3
[  184.257813] Hardware name: STi SoC with Flattened Device Tree
[  184.257818] PC is at pci_read32_sync+0x10/0x14 [rtl_pci]
[  184.257860] LR is at rtl92ce_enable_interrupt+0x4c/0x8c [rtl8192ce]
[  184.257921] pc : [<bf46d03c>]    lr : [<bf478e44>]    psr: 20060013
[  184.257928] sp : f1375ce0  ip : bf451b34  fp : c14f3c00
[  184.257933] r10: c2c4b780  r9 : c28f4000  r8 : c15b18bc
[  184.257938] r7 : 00000000  r6 : c15bd880  r5 : c15bc880  r4 : c15b1880
[  184.257944] r3 : f09e8000  r2 : 00000730  r1 : f09e8120  r0 : 00001b5f
[  184.257950] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[  184.257959] Control: 10c5387d  Table: 86c0804a  DAC: 00000051
[  184.257970]  pci_read32_sync [rtl_pci] from rtl92ce_enable_interrupt+0x4c/0x8c [rtl8192ce]
[  184.258018]  rtl92ce_enable_interrupt [rtl8192ce] from rtl_pci_start+0xbc/0x18c [rtl_pci]
[  184.258059]  rtl_pci_start [rtl_pci] from rtl_op_start+0x58/0x7c [rtlwifi]
[  184.258269]  rtl_op_start [rtlwifi] from drv_start+0x4c/0x10c [mac80211]
[  184.259512]  drv_start [mac80211] from ieee80211_do_open+0x370/0x6d8 [mac80211]
[  184.260444]  ieee80211_do_open [mac80211] from ieee80211_open+0x60/0x84 [mac80211]
[  184.261374]  ieee80211_open [mac80211] from __dev_open+0xfc/0x1d0
[  184.261860]  __dev_open from __dev_change_flags+0x190/0x214
[  184.261878]  __dev_change_flags from dev_change_flags+0x20/0x5c
[  184.261894]  dev_change_flags from devinet_ioctl+0x7a8/0x7dc
[  184.261918]  devinet_ioctl from inet_ioctl+0x1a4/0x244
[  184.261937]  inet_ioctl from sock_ioctl+0x4dc/0x5b8
[  184.261962]  sock_ioctl from sys_ioctl+0x510/0xbd8
[  184.261985]  sys_ioctl from ret_fast_syscall+0x0/0x1c
[  184.262000] Exception stack(0xf1375fa8 to 0xf1375ff0)
[  184.262011] 5fa0:                   005a8bcd beedbb10 00000003 00008914 beedbb10 beedbaa8
[  184.262020] 5fc0: 005a8bcd beedbb10 beedbe18 00000036 beedbcf8 00000003 b6f34d78 b6f35048
[  184.262027] 5fe0: 005c81f8 beedba90 004fe2d8 b6e4c758

HowTo reproduce

# Wake up interface
ifconfig wlan0 up
# (optional) can check if wifi is working for you (=> show AP nearby)
iw dev wlan0 scan 

# loop up/down wifi interface (...wait a bit...)
while : ; do ifconfig wlan0 up; ifconfig wlan0 down; echo -n "."; done

@waby38b
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waby38b commented Mar 30, 2023

So, I have a first ~working solution, check this branch

drivers/net/wireless/realtek/rtlwifi/rtl8192ce/hw.c |    7 +++++++
1 file changed, 7 insertions(+)

Seem that stacktrace show an interrupt issue.... So, as a first try, I just make protection on enable/disable interrupt
Now, we can use NetworkManager ~without any issue, and no more hard crash!
Others rtlwifi drivers should also be affected.... (I don't have HW to check...)

Anyway, even with this patch, we may (low rate) got some not expected msg from kernel
when switching from AP discover and AP usage. This is exactly what NetworkManager do in background
So, this patch need to be tuned

    [ 1011.101387] ------------[ cut here ]------------
    [ 1011.101399] WARNING: CPU: 0 PID: 528 at net/mac80211/rx.c:5146 ieee80211_rx_list+0x6bc/0xd38 [mac80211]
    [ 1011.102736] CPU: 0 PID: 528 Comm: apps.plugin Not tainted 6.2.9 #17
    [ 1011.102751] Hardware name: STi SoC with Flattened Device Tree
    [ 1011.102763]  unwind_backtrace from show_stack+0x18/0x1c
    [ 1011.102794]  show_stack from dump_stack_lvl+0x58/0x70
    [ 1011.102823]  dump_stack_lvl from __warn+0x84/0x12c
    [ 1011.102857]  __warn from warn_slowpath_fmt+0xb4/0x18c
    [ 1011.102886]  warn_slowpath_fmt from ieee80211_rx_list+0x6bc/0xd38 [mac80211]
    [ 1011.103835]  ieee80211_rx_list [mac80211] from ieee80211_rx_napi+0x38/0xb0 [mac80211]
    [ 1011.105676]  ieee80211_rx_napi [mac80211] from ieee80211_tasklet_handler+0xd8/0xdc [mac80211]
    [ 1011.107055]  ieee80211_tasklet_handler [mac80211] from tasklet_action_common.constprop.0+0xf8/0x128
    [ 1011.107875]  tasklet_action_common.constprop.0 from __do_softirq+0x168/0x400
    [ 1011.107912]  __do_softirq from __irq_exit_rcu+0xa4/0xc8
    [ 1011.107939]  __irq_exit_rcu from irq_exit+0x10/0x30
    [ 1011.107969]  irq_exit from call_with_stack+0x18/0x20
    [ 1011.108004]  call_with_stack from __irq_svc+0x9c/0xb8
    [ 1011.108027] Exception stack(0xf0c29ed0 to 0xf0c29f18)
    [ 1011.108045] 9ec0:                                     c01a4788 00000000 2c629000 60000093
    [ 1011.108054] 9ee0: 00000000 c4d9d778 c4d9d100 c2adbd08 0000069c fffffe30 5ac3c35a c2a04d8c
    [ 1011.108062] 9f00: 00000000 f0c29f20 c014b488 c071105c 60000013 ffffffff
    [ 1011.108068]  __irq_svc from __cond_resched+0x0/0x54
    [ 1011.108082]  __cond_resched from task_work_run+0xa4/0xcc
    [ 1011.108100]  task_work_run from do_work_pending+0x448/0x51c
    [ 1011.108116]  do_work_pending from slow_work_pending+0xc/0x20
    [ 1011.108126] Exception stack(0xf0c29fb0 to 0xf0c29ff8)
    [ 1011.108134] 9fa0:                                     fffffffe 005467f0 00028000 00000000
    [ 1011.108142] 9fc0: 004a99e8 00000001 004a1400 00000142 005467f0 00000000 0049ec48 00000000
    [ 1011.108150] 9fe0: 00000001 be9650b8 00000000 b6b02660 80000010 ffffff9c
    [ 1011.108210] ---[ end trace 0000000000000000 ]---
    [ 1011.108229] ------------[ cut here ]------------

@waby38b
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waby38b commented Apr 6, 2023

Here second version of my patch.

 drivers/net/wireless/realtek/rtlwifi/core.c |    4 +++-
 drivers/net/wireless/realtek/rtlwifi/pci.c  |   12 ++++++++++--
 drivers/net/wireless/realtek/rtlwifi/ps.c   |    6 ++++++
 3 files changed, 19 insertions(+), 3 deletions(-)

No more localized in rtl92ce_{enable|disable}_interrupt() but in rtlwifi framework.
All realteck drivers follow sames rules, so every RTLxxx card should raise same locking issue

I do not (yet!) see any drawback like with patch n°1, so seem safe ! (cross finger)

We may reduced later this patch, but let's take some time to test !

avolmat pushed a commit that referenced this issue Apr 7, 2023
The following LOCKDEP was detected:
		Workqueue: events smc_lgr_free_work [smc]
		WARNING: possible circular locking dependency detected
		6.1.0-20221027.rc2.git8.56bc5b569087.300.fc36.s390x+debug #1 Not tainted
		------------------------------------------------------
		kworker/3:0/176251 is trying to acquire lock:
		00000000f1467148 ((wq_completion)smc_tx_wq-00000000#2){+.+.}-{0:0},
			at: __flush_workqueue+0x7a/0x4f0
		but task is already holding lock:
		0000037fffe97dc8 ((work_completion)(&(&lgr->free_work)->work)){+.+.}-{0:0},
			at: process_one_work+0x232/0x730
		which lock already depends on the new lock.
		the existing dependency chain (in reverse order) is:
		-> #4 ((work_completion)(&(&lgr->free_work)->work)){+.+.}-{0:0}:
		       __lock_acquire+0x58e/0xbd8
		       lock_acquire.part.0+0xe2/0x248
		       lock_acquire+0xac/0x1c8
		       __flush_work+0x76/0xf0
		       __cancel_work_timer+0x170/0x220
		       __smc_lgr_terminate.part.0+0x34/0x1c0 [smc]
		       smc_connect_rdma+0x15e/0x418 [smc]
		       __smc_connect+0x234/0x480 [smc]
		       smc_connect+0x1d6/0x230 [smc]
		       __sys_connect+0x90/0xc0
		       __do_sys_socketcall+0x186/0x370
		       __do_syscall+0x1da/0x208
		       system_call+0x82/0xb0
		-> #3 (smc_client_lgr_pending){+.+.}-{3:3}:
		       __lock_acquire+0x58e/0xbd8
		       lock_acquire.part.0+0xe2/0x248
		       lock_acquire+0xac/0x1c8
		       __mutex_lock+0x96/0x8e8
		       mutex_lock_nested+0x32/0x40
		       smc_connect_rdma+0xa4/0x418 [smc]
		       __smc_connect+0x234/0x480 [smc]
		       smc_connect+0x1d6/0x230 [smc]
		       __sys_connect+0x90/0xc0
		       __do_sys_socketcall+0x186/0x370
		       __do_syscall+0x1da/0x208
		       system_call+0x82/0xb0
		-> #2 (sk_lock-AF_SMC){+.+.}-{0:0}:
		       __lock_acquire+0x58e/0xbd8
		       lock_acquire.part.0+0xe2/0x248
		       lock_acquire+0xac/0x1c8
		       lock_sock_nested+0x46/0xa8
		       smc_tx_work+0x34/0x50 [smc]
		       process_one_work+0x30c/0x730
		       worker_thread+0x62/0x420
		       kthread+0x138/0x150
		       __ret_from_fork+0x3c/0x58
		       ret_from_fork+0xa/0x40
		-> #1 ((work_completion)(&(&smc->conn.tx_work)->work)){+.+.}-{0:0}:
		       __lock_acquire+0x58e/0xbd8
		       lock_acquire.part.0+0xe2/0x248
		       lock_acquire+0xac/0x1c8
		       process_one_work+0x2bc/0x730
		       worker_thread+0x62/0x420
		       kthread+0x138/0x150
		       __ret_from_fork+0x3c/0x58
		       ret_from_fork+0xa/0x40
		-> #0 ((wq_completion)smc_tx_wq-00000000#2){+.+.}-{0:0}:
		       check_prev_add+0xd8/0xe88
		       validate_chain+0x70c/0xb20
		       __lock_acquire+0x58e/0xbd8
		       lock_acquire.part.0+0xe2/0x248
		       lock_acquire+0xac/0x1c8
		       __flush_workqueue+0xaa/0x4f0
		       drain_workqueue+0xaa/0x158
		       destroy_workqueue+0x44/0x2d8
		       smc_lgr_free+0x9e/0xf8 [smc]
		       process_one_work+0x30c/0x730
		       worker_thread+0x62/0x420
		       kthread+0x138/0x150
		       __ret_from_fork+0x3c/0x58
		       ret_from_fork+0xa/0x40
		other info that might help us debug this:
		Chain exists of:
		  (wq_completion)smc_tx_wq-00000000#2
	  	  --> smc_client_lgr_pending
		  --> (work_completion)(&(&lgr->free_work)->work)
		 Possible unsafe locking scenario:
		       CPU0                    CPU1
		       ----                    ----
		  lock((work_completion)(&(&lgr->free_work)->work));
		                   lock(smc_client_lgr_pending);
		                   lock((work_completion)
					(&(&lgr->free_work)->work));
		  lock((wq_completion)smc_tx_wq-00000000#2);
		 *** DEADLOCK ***
		2 locks held by kworker/3:0/176251:
		 #0: 0000000080183548
			((wq_completion)events){+.+.}-{0:0},
				at: process_one_work+0x232/0x730
		 #1: 0000037fffe97dc8
			((work_completion)
			 (&(&lgr->free_work)->work)){+.+.}-{0:0},
				at: process_one_work+0x232/0x730
		stack backtrace:
		CPU: 3 PID: 176251 Comm: kworker/3:0 Not tainted
		Hardware name: IBM 8561 T01 701 (z/VM 7.2.0)
		Call Trace:
		 [<000000002983c3e4>] dump_stack_lvl+0xac/0x100
		 [<0000000028b477ae>] check_noncircular+0x13e/0x160
		 [<0000000028b48808>] check_prev_add+0xd8/0xe88
		 [<0000000028b49cc4>] validate_chain+0x70c/0xb20
		 [<0000000028b4bd26>] __lock_acquire+0x58e/0xbd8
		 [<0000000028b4cf6a>] lock_acquire.part.0+0xe2/0x248
		 [<0000000028b4d17c>] lock_acquire+0xac/0x1c8
		 [<0000000028addaaa>] __flush_workqueue+0xaa/0x4f0
		 [<0000000028addf9a>] drain_workqueue+0xaa/0x158
		 [<0000000028ae303c>] destroy_workqueue+0x44/0x2d8
		 [<000003ff8029af26>] smc_lgr_free+0x9e/0xf8 [smc]
		 [<0000000028adf3d4>] process_one_work+0x30c/0x730
		 [<0000000028adf85a>] worker_thread+0x62/0x420
		 [<0000000028aeac50>] kthread+0x138/0x150
		 [<0000000028a63914>] __ret_from_fork+0x3c/0x58
		 [<00000000298503da>] ret_from_fork+0xa/0x40
		INFO: lockdep is turned off.
===================================================================

This deadlock occurs because cancel_delayed_work_sync() waits for
the work(&lgr->free_work) to finish, while the &lgr->free_work
waits for the work(lgr->tx_wq), which needs the sk_lock-AF_SMC, that
is already used under the mutex_lock.

The solution is to use cancel_delayed_work() instead, which kills
off a pending work.

Fixes: a52bcc9 ("net/smc: improve termination processing")
Signed-off-by: Wenjia Zhang <[email protected]>
Reviewed-by: Jan Karcher <[email protected]>
Reviewed-by: Karsten Graul <[email protected]>
Reviewed-by: Tony Lu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
avolmat pushed a commit that referenced this issue Apr 7, 2023
The check introduced in the commit a5fd394 ("igc: Lift TAPRIO schedule
restriction") can detect a false positive error in some corner case.
For instance,
    tc qdisc replace ... taprio num_tc 4
	...
	sched-entry S 0x01 100000	# slot#1
	sched-entry S 0x03 100000	# slot#2
	sched-entry S 0x04 100000	# slot#3
	sched-entry S 0x08 200000	# slot#4
	flags 0x02			# hardware offload

Here the queue#0 (the first queue) is on at the slot#1 and #2,
and off at the slot#3 and #4. Under the current logic, when the slot#4
is examined, validate_schedule() returns *false* since the enablement
count for the queue#0 is two and it is already off at the previous slot
(i.e. #3). But this definition is truely correct.

Let's fix the logic to enforce a strict validation for consecutively-opened
slots.

Fixes: a5fd394 ("igc: Lift TAPRIO schedule restriction")
Signed-off-by: AKASHI Takahiro <[email protected]>
Reviewed-by: Kurt Kanzenbach <[email protected]>
Acked-by: Vinicius Costa Gomes <[email protected]>
Tested-by: Naama Meir <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>
avolmat pushed a commit that referenced this issue Apr 7, 2023
When a system with E810 with existing VFs gets rebooted the following
hang may be observed.

 Pid 1 is hung in iavf_remove(), part of a network driver:
 PID: 1        TASK: ffff965400e5a340  CPU: 24   COMMAND: "systemd-shutdow"
  #0 [ffffaad04005fa50] __schedule at ffffffff8b3239cb
  #1 [ffffaad04005fae8] schedule at ffffffff8b323e2d
  #2 [ffffaad04005fb00] schedule_hrtimeout_range_clock at ffffffff8b32cebc
  #3 [ffffaad04005fb80] usleep_range_state at ffffffff8b32c930
  #4 [ffffaad04005fbb0] iavf_remove at ffffffffc12b9b4c [iavf]
  #5 [ffffaad04005fbf0] pci_device_remove at ffffffff8add7513
  #6 [ffffaad04005fc10] device_release_driver_internal at ffffffff8af08baa
  #7 [ffffaad04005fc40] pci_stop_bus_device at ffffffff8adcc5fc
  #8 [ffffaad04005fc60] pci_stop_and_remove_bus_device at ffffffff8adcc81e
  #9 [ffffaad04005fc70] pci_iov_remove_virtfn at ffffffff8adf9429
 #10 [ffffaad04005fca8] sriov_disable at ffffffff8adf98e4
 #11 [ffffaad04005fcc8] ice_free_vfs at ffffffffc04bb2c8 [ice]
 torvalds#12 [ffffaad04005fd10] ice_remove at ffffffffc04778fe [ice]
 torvalds#13 [ffffaad04005fd38] ice_shutdown at ffffffffc0477946 [ice]
 torvalds#14 [ffffaad04005fd50] pci_device_shutdown at ffffffff8add58f1
 torvalds#15 [ffffaad04005fd70] device_shutdown at ffffffff8af05386
 torvalds#16 [ffffaad04005fd98] kernel_restart at ffffffff8a92a870
 torvalds#17 [ffffaad04005fda8] __do_sys_reboot at ffffffff8a92abd6
 torvalds#18 [ffffaad04005fee0] do_syscall_64 at ffffffff8b317159
 torvalds#19 [ffffaad04005ff08] __context_tracking_enter at ffffffff8b31b6fc
 torvalds#20 [ffffaad04005ff18] syscall_exit_to_user_mode at ffffffff8b31b50d
 torvalds#21 [ffffaad04005ff28] do_syscall_64 at ffffffff8b317169
 torvalds#22 [ffffaad04005ff50] entry_SYSCALL_64_after_hwframe at ffffffff8b40009b
     RIP: 00007f1baa5c13d7  RSP: 00007fffbcc55a98  RFLAGS: 00000202
     RAX: ffffffffffffffda  RBX: 0000000000000000  RCX: 00007f1baa5c13d7
     RDX: 0000000001234567  RSI: 0000000028121969  RDI: 00000000fee1dead
     RBP: 00007fffbcc55ca0   R8: 0000000000000000   R9: 00007fffbcc54e90
     R10: 00007fffbcc55050  R11: 0000000000000202  R12: 0000000000000005
     R13: 0000000000000000  R14: 00007fffbcc55af0  R15: 0000000000000000
     ORIG_RAX: 00000000000000a9  CS: 0033  SS: 002b

During reboot all drivers PM shutdown callbacks are invoked.
In iavf_shutdown() the adapter state is changed to __IAVF_REMOVE.
In ice_shutdown() the call chain above is executed, which at some point
calls iavf_remove(). However iavf_remove() expects the VF to be in one
of the states __IAVF_RUNNING, __IAVF_DOWN or __IAVF_INIT_FAILED. If
that's not the case it sleeps forever.
So if iavf_shutdown() gets invoked before iavf_remove() the system will
hang indefinitely because the adapter is already in state __IAVF_REMOVE.

Fix this by returning from iavf_remove() if the state is __IAVF_REMOVE,
as we already went through iavf_shutdown().

Fixes: 9745780 ("iavf: Add waiting so the port is initialized in remove")
Fixes: a841733 ("iavf: Fix race condition between iavf_shutdown and iavf_remove")
Reported-by: Marius Cornea <[email protected]>
Signed-off-by: Stefan Assmann <[email protected]>
Reviewed-by: Michal Kubiak <[email protected]>
Tested-by: Rafal Romanowski <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>
@waby38b
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waby38b commented Apr 11, 2023

Here third version of the rtlwifi patch (hope that it's the last one!)

 drivers/net/wireless/realtek/rtlwifi/pci.c |    5 +++++
 drivers/net/wireless/realtek/rtlwifi/ps.c  |    3 +++
 2 files changed, 8 insertions(+)

Patch v2 still generate some WARN (but no error or hang)

[297627.187798] ------------[ cut here ]------------
[297627.187831] WARNING: CPU: 3 PID: 0 at net/mac80211/rx.c:5146 ieee80211_rx_list+0xb0/0xae0 [mac80211]
[297627.190485] Modules linked in: nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables nfnetlink qrtr sunrpc vfat fat rtl8192ce rtl_pci rtl8192c_common rtlwifi mac80211 libarc4 cfg80211 snd_soc_sti_sas snd_soc_simple_card ni_usb_gpib(OE) snd_soc_sti snd_soc_simple_card_utils gpib_common(OE) snd_soc_core rfkill ssd130x_i2c ac97_bus ssd130x snd_seq leds_gpio snd_pcm_dmaengine snd_seq_device ssd1307fb st_remoteproc snd_pcm st_delta videobuf2_dma_contig ofpart videobuf2_memops v4l2_mem2mem videobuf2_v4l2 st_spi_fsm videobuf2_common mtd snd_timer st_thermal_memmap videodev st_thermal snd soundcore st_rng mc rpmsg_core cpufreq_dt fuse zram dwmac_generic xhci_plat_hcd dwc3 dwmac_sti stmmac_platform ulpi mmc_block udc_core stmmac pcs_xpcs ehci_st pcie_sti ohci_st ahci_st ohci_hcd phylink libahci_platform sdhci_st i2c_st pwm_sti sdhci_pltfm sdhci sti_drm st_fdma
[297627.191474]  st_slim_rproc st_lpc_wdt drm_dma_helper rtc_st_lpc dwc3_st cec mailbox_sti phy_miphy28lp phy_stih407_usb sti_cpufreq
[297627.191591] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G        W  OE      6.2.10-100.4kopen.fc36.armv7hl #1
[297627.191613] Hardware name: STi SoC with Flattened Device Tree
[297627.191633]  unwind_backtrace from show_stack+0x18/0x1c
[297627.191675]  show_stack from dump_stack_lvl+0x40/0x4c
[297627.191716]  dump_stack_lvl from __warn+0x78/0x114
[297627.191748]  __warn from warn_slowpath_fmt+0xa8/0x12c
[297627.191773]  warn_slowpath_fmt from ieee80211_rx_list+0xb0/0xae0 [mac80211]
[297627.193854]  ieee80211_rx_list [mac80211] from ieee80211_rx_napi+0x34/0xa4 [mac80211]
[297627.196705]  ieee80211_rx_napi [mac80211] from ieee80211_tasklet_handler+0x9c/0xc0 [mac80211]
[297627.199489]  ieee80211_tasklet_handler [mac80211] from tasklet_action_common.constprop.0+0x80/0xb8
[297627.200810]  tasklet_action_common.constprop.0 from __do_softirq+0x1e0/0x2a4
[297627.200850]  __do_softirq from __irq_exit_rcu+0x84/0xfc
[297627.200880]  __irq_exit_rcu from irq_exit+0x10/0x18
[297627.200915]  irq_exit from call_with_stack+0x18/0x20
[297627.200963]  call_with_stack from __irq_svc+0x98/0xb0
[297627.200992] Exception stack(0xf08b1f50 to 0xf08b1f98)
[297627.201009] 1f40:                                     eede997c 2d593000 00000003 c031b700
[297627.201026] 1f60: c2164800 00000000 c2164800 c1857a70 00000003 c190a0f8 00000000 00000000
[297627.201041] 1f80: f0853200 f08b1fa0 c0307e2c c0307e10 60000013 ffffffff
[297627.201052]  __irq_svc from arch_cpu_idle+0x24/0x4c
[297627.201088]  arch_cpu_idle from default_idle_call+0x38/0x54
[297627.201122]  default_idle_call from do_idle+0x10c/0x284
[297627.201159]  do_idle from cpu_startup_entry+0x20/0x24
[297627.201191]  cpu_startup_entry from secondary_start_kernel+0x1c0/0x1e8
[297627.201230]  secondary_start_kernel from 0x80301640
[297627.201323] ---[ end trace 0000000000000000 ]---

So, tweak again and reduce as low as possible locking and remove unneeded changes (mutex)

Let's again wait for a final conclusion

Here my updated script for stress testing ( waby38 is my Wifi AP)
while : ; do /etc/init.d/S45network-manager stop; for ((i=1;i<=1000;i++)); do ifconfig wlp1s0 up; ifconfig wlp1s0 down; echo -n "."; done; /etc/init.d/S45network-manager start; for ((i=1;i<=20;i++)); do sleep 5; nmcli connection up way38; echo -n "u"; nmcli device wifi rescan && nmcli device wifi list; sleep 5; nmcli connection down waby38; echo -n "d"; nmcli device wifi rescan && nmcli device wifi list; done; done

And ply provide some useful stats
ply 'kprobe:rtl92ce_*_interrupt { @[comm, uid, pid, kpid, caller] = count(); if (pid == 0) print(stack); } '

@waby38b
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Collaborator Author

waby38b commented Apr 14, 2023

Patchv4 (CodeName: I'm back!)

 drivers/net/wireless/realtek/rtlwifi/core.c | 18 +++++++++++++++++-
 drivers/net/wireless/realtek/rtlwifi/pci.c  |  5 +++++
 drivers/net/wireless/realtek/rtlwifi/ps.c   |  3 +++
 3 files changed, 25 insertions(+), 1 deletion(-)

Tested a new path in ieee80211 stack: Access Point!
And this raise (again, low fhz) new locking issue...

[  126.781074]  pci_read32_sync [rtl_pci] from rtl92ce_enable_interrupt+0x24/0x44 [rtl8192ce]
[  126.781126]  rtl92ce_enable_interrupt [rtl8192ce] from rtl_op_bss_info_changed+0x1a0/0x6f0 [rtlwifi]
[  126.781321]  rtl_op_bss_info_changed [rtlwifi] from drv_link_info_changed+0x1cc/0x1e4 [mac80211]
[  126.783142]  drv_link_info_changed [mac80211] from ieee80211_link_info_change_notify+0xd8/0xec [mac80211]
[  126.784637]  ieee80211_link_info_change_notify [mac80211] from ieee80211_start_ap+0x60c/0x68c [mac80211]
[  126.786143]  ieee80211_start_ap [mac80211] from nl80211_start_ap+0xa2c/0xb24 [cfg80211]
[  126.788642]  nl80211_start_ap [cfg80211] from genl_rcv_msg+0x220/0x368
[  126.789308]  genl_rcv_msg from netlink_rcv_skb+0xac/0x114
[  126.789327]  netlink_rcv_skb from genl_rcv+0x28/0x3c
[  126.789342]  genl_rcv from netlink_unicast+0x12c/0x1d4
[  126.789357]  netlink_unicast from netlink_sendmsg+0x374/0x3a4
[  126.789372]  netlink_sendmsg from sock_sendmsg_nosec+0x14/0x24
[  126.789398]  sock_sendmsg_nosec from ____sys_sendmsg+0x174/0x21c
[  126.789417]  ____sys_sendmsg from ___sys_sendmsg+0x9c/0xd4
[  126.789434]  ___sys_sendmsg from __sys_sendmsg+0x74/0xb0
[  126.789445]  __sys_sendmsg from ret_fast_syscall+0x0/0x1c

Now, issue is detected in rtlwifi/core.c (rtl_op_bss_info_changed) when we enable AP (nl80211_start_ap)

After analysis, I confirm that 3 new entries may be call interrupt_{enable|disable} without any protection

  .update_interrupt_mask = rtl92ce_update_interrupt_mask,
  .set_bcn_intv = rtl92ce_set_beacon_interval,
  .set_bcn_reg = rtl92ce_set_beacon_related_registers,

rtl_op_add_interface()
  1 x update_interrupt_mask()
  2 x set_bcn_reg()

rtl_op_remove_interface()
  1 x update_interrupt_mask()

rtl_op_bss_info_changed()
  2 x update_interrupt_mask()
  1 x set_bcn_intv()

HowToCheck:
while : ; do nmcli c u "Wi-Fi AP"; echo -n "."; nmcli c d "Wi-Fi AP"; done

@waby38b waby38b added the bug Something isn't working label Apr 14, 2023
@waby38b waby38b self-assigned this Apr 14, 2023
avolmat pushed a commit that referenced this issue Apr 16, 2023
Commit c14f7cc ("PCI: Assign PCI domain IDs by ida_alloc()")
introduced a use-after-free bug in the bus removal cleanup. The issue was
found with kfence:

  [   19.293351] BUG: KFENCE: use-after-free read in pci_bus_release_domain_nr+0x10/0x70

  [   19.302817] Use-after-free read at 0x000000007f3b80eb (in kfence-torvalds#115):
  [   19.309677]  pci_bus_release_domain_nr+0x10/0x70
  [   19.309691]  dw_pcie_host_deinit+0x28/0x78
  [   19.309702]  tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194]
  [   19.309734]  tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194]
  [   19.309752]  platform_probe+0x90/0xd8
  ...

  [   19.311457] kfence-torvalds#115: 0x00000000063a155a-0x00000000ba698da8, size=1072, cache=kmalloc-2k

  [   19.311469] allocated by task 96 on cpu 10 at 19.279323s:
  [   19.311562]  __kmem_cache_alloc_node+0x260/0x278
  [   19.311571]  kmalloc_trace+0x24/0x30
  [   19.311580]  pci_alloc_bus+0x24/0xa0
  [   19.311590]  pci_register_host_bridge+0x48/0x4b8
  [   19.311601]  pci_scan_root_bus_bridge+0xc0/0xe8
  [   19.311613]  pci_host_probe+0x18/0xc0
  [   19.311623]  dw_pcie_host_init+0x2c0/0x568
  [   19.311630]  tegra_pcie_dw_probe+0x610/0xb28 [pcie_tegra194]
  [   19.311647]  platform_probe+0x90/0xd8
  ...

  [   19.311782] freed by task 96 on cpu 10 at 19.285833s:
  [   19.311799]  release_pcibus_dev+0x30/0x40
  [   19.311808]  device_release+0x30/0x90
  [   19.311814]  kobject_put+0xa8/0x120
  [   19.311832]  device_unregister+0x20/0x30
  [   19.311839]  pci_remove_bus+0x78/0x88
  [   19.311850]  pci_remove_root_bus+0x5c/0x98
  [   19.311860]  dw_pcie_host_deinit+0x28/0x78
  [   19.311866]  tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194]
  [   19.311883]  tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194]
  [   19.311900]  platform_probe+0x90/0xd8
  ...

  [   19.313579] CPU: 10 PID: 96 Comm: kworker/u24:2 Not tainted 6.2.0 #4
  [   19.320171] Hardware name:  /, BIOS 1.0-d7fb19b 08/10/2022
  [   19.325852] Workqueue: events_unbound deferred_probe_work_func

The stack trace is a bit misleading as dw_pcie_host_deinit() doesn't
directly call pci_bus_release_domain_nr(). The issue turns out to be in
pci_remove_root_bus() which first calls pci_remove_bus() which frees the
struct pci_bus when its struct device is released. Then
pci_bus_release_domain_nr() is called and accesses the freed struct
pci_bus. Reordering these fixes the issue.

Fixes: c14f7cc ("PCI: Assign PCI domain IDs by ida_alloc()")
Link: https://lore.kernel.org/r/[email protected]
Link: https://lore.kernel.org/r/[email protected]
Reported-by: Jon Hunter <[email protected]>
Tested-by: Jon Hunter <[email protected]>
Signed-off-by: Rob Herring <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Kuppuswamy Sathyanarayanan <[email protected]>
Cc: [email protected]	# v6.2+
Cc: Pali Rohár <[email protected]>
waby38b pushed a commit that referenced this issue Apr 20, 2023
Commit c14f7cc ("PCI: Assign PCI domain IDs by ida_alloc()")
introduced a use-after-free bug in the bus removal cleanup. The issue was
found with kfence:

  [   19.293351] BUG: KFENCE: use-after-free read in pci_bus_release_domain_nr+0x10/0x70

  [   19.302817] Use-after-free read at 0x000000007f3b80eb (in kfence-torvalds#115):
  [   19.309677]  pci_bus_release_domain_nr+0x10/0x70
  [   19.309691]  dw_pcie_host_deinit+0x28/0x78
  [   19.309702]  tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194]
  [   19.309734]  tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194]
  [   19.309752]  platform_probe+0x90/0xd8
  ...

  [   19.311457] kfence-torvalds#115: 0x00000000063a155a-0x00000000ba698da8, size=1072, cache=kmalloc-2k

  [   19.311469] allocated by task 96 on cpu 10 at 19.279323s:
  [   19.311562]  __kmem_cache_alloc_node+0x260/0x278
  [   19.311571]  kmalloc_trace+0x24/0x30
  [   19.311580]  pci_alloc_bus+0x24/0xa0
  [   19.311590]  pci_register_host_bridge+0x48/0x4b8
  [   19.311601]  pci_scan_root_bus_bridge+0xc0/0xe8
  [   19.311613]  pci_host_probe+0x18/0xc0
  [   19.311623]  dw_pcie_host_init+0x2c0/0x568
  [   19.311630]  tegra_pcie_dw_probe+0x610/0xb28 [pcie_tegra194]
  [   19.311647]  platform_probe+0x90/0xd8
  ...

  [   19.311782] freed by task 96 on cpu 10 at 19.285833s:
  [   19.311799]  release_pcibus_dev+0x30/0x40
  [   19.311808]  device_release+0x30/0x90
  [   19.311814]  kobject_put+0xa8/0x120
  [   19.311832]  device_unregister+0x20/0x30
  [   19.311839]  pci_remove_bus+0x78/0x88
  [   19.311850]  pci_remove_root_bus+0x5c/0x98
  [   19.311860]  dw_pcie_host_deinit+0x28/0x78
  [   19.311866]  tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194]
  [   19.311883]  tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194]
  [   19.311900]  platform_probe+0x90/0xd8
  ...

  [   19.313579] CPU: 10 PID: 96 Comm: kworker/u24:2 Not tainted 6.2.0 #4
  [   19.320171] Hardware name:  /, BIOS 1.0-d7fb19b 08/10/2022
  [   19.325852] Workqueue: events_unbound deferred_probe_work_func

The stack trace is a bit misleading as dw_pcie_host_deinit() doesn't
directly call pci_bus_release_domain_nr(). The issue turns out to be in
pci_remove_root_bus() which first calls pci_remove_bus() which frees the
struct pci_bus when its struct device is released. Then
pci_bus_release_domain_nr() is called and accesses the freed struct
pci_bus. Reordering these fixes the issue.

Fixes: c14f7cc ("PCI: Assign PCI domain IDs by ida_alloc()")
Link: https://lore.kernel.org/r/[email protected]
Link: https://lore.kernel.org/r/[email protected]
Reported-by: Jon Hunter <[email protected]>
Tested-by: Jon Hunter <[email protected]>
Signed-off-by: Rob Herring <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Kuppuswamy Sathyanarayanan <[email protected]>
Cc: [email protected]	# v6.2+
Cc: Pali Rohár <[email protected]>
avolmat pushed a commit that referenced this issue Apr 24, 2023
…kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.3, part #4

 - Plug a buffer overflow due to the use of the user-provided register
   width for firmware regs. Outright reject accesses where the
   user register width does not match the kernel representation.

 - Protect non-atomic RMW operations on vCPU flags against preemption,
   as an update to the flags by an intervening preemption could be lost.
avolmat pushed a commit that referenced this issue Jun 10, 2023
The cited commit adds a compeletion to remove dependency on rtnl
lock. But it causes a deadlock for multiple encapsulations:

 crash> bt ffff8aece8a64000
 PID: 1514557  TASK: ffff8aece8a64000  CPU: 3    COMMAND: "tc"
  #0 [ffffa6d14183f368] __schedule at ffffffffb8ba7f45
  #1 [ffffa6d14183f3f8] schedule at ffffffffb8ba8418
  #2 [ffffa6d14183f418] schedule_preempt_disabled at ffffffffb8ba8898
  #3 [ffffa6d14183f428] __mutex_lock at ffffffffb8baa7f8
  #4 [ffffa6d14183f4d0] mutex_lock_nested at ffffffffb8baabeb
  #5 [ffffa6d14183f4e0] mlx5e_attach_encap at ffffffffc0f48c17 [mlx5_core]
  #6 [ffffa6d14183f628] mlx5e_tc_add_fdb_flow at ffffffffc0f39680 [mlx5_core]
  #7 [ffffa6d14183f688] __mlx5e_add_fdb_flow at ffffffffc0f3b636 [mlx5_core]
  #8 [ffffa6d14183f6f0] mlx5e_tc_add_flow at ffffffffc0f3bcdf [mlx5_core]
  #9 [ffffa6d14183f728] mlx5e_configure_flower at ffffffffc0f3c1d1 [mlx5_core]
 #10 [ffffa6d14183f790] mlx5e_rep_setup_tc_cls_flower at ffffffffc0f3d529 [mlx5_core]
 #11 [ffffa6d14183f7a0] mlx5e_rep_setup_tc_cb at ffffffffc0f3d714 [mlx5_core]
 torvalds#12 [ffffa6d14183f7b0] tc_setup_cb_add at ffffffffb8931bb8
 torvalds#13 [ffffa6d14183f810] fl_hw_replace_filter at ffffffffc0dae901 [cls_flower]
 torvalds#14 [ffffa6d14183f8d8] fl_change at ffffffffc0db5c57 [cls_flower]
 torvalds#15 [ffffa6d14183f970] tc_new_tfilter at ffffffffb8936047
 torvalds#16 [ffffa6d14183fac8] rtnetlink_rcv_msg at ffffffffb88c7c31
 torvalds#17 [ffffa6d14183fb50] netlink_rcv_skb at ffffffffb8942853
 torvalds#18 [ffffa6d14183fbc0] rtnetlink_rcv at ffffffffb88c1835
 torvalds#19 [ffffa6d14183fbd0] netlink_unicast at ffffffffb8941f27
 torvalds#20 [ffffa6d14183fc18] netlink_sendmsg at ffffffffb8942245
 torvalds#21 [ffffa6d14183fc98] sock_sendmsg at ffffffffb887d482
 torvalds#22 [ffffa6d14183fcb8] ____sys_sendmsg at ffffffffb887d81a
 torvalds#23 [ffffa6d14183fd38] ___sys_sendmsg at ffffffffb88806e2
 torvalds#24 [ffffa6d14183fe90] __sys_sendmsg at ffffffffb88807a2
 torvalds#25 [ffffa6d14183ff28] __x64_sys_sendmsg at ffffffffb888080f
 torvalds#26 [ffffa6d14183ff38] do_syscall_64 at ffffffffb8b9b6a8
 torvalds#27 [ffffa6d14183ff50] entry_SYSCALL_64_after_hwframe at ffffffffb8c0007c
 crash> bt 0xffff8aeb07544000
 PID: 1110766  TASK: ffff8aeb07544000  CPU: 0    COMMAND: "kworker/u20:9"
  #0 [ffffa6d14e6b7bd8] __schedule at ffffffffb8ba7f45
  #1 [ffffa6d14e6b7c68] schedule at ffffffffb8ba8418
  #2 [ffffa6d14e6b7c88] schedule_timeout at ffffffffb8baef88
  #3 [ffffa6d14e6b7d10] wait_for_completion at ffffffffb8ba968b
  #4 [ffffa6d14e6b7d60] mlx5e_take_all_encap_flows at ffffffffc0f47ec4 [mlx5_core]
  #5 [ffffa6d14e6b7da0] mlx5e_rep_update_flows at ffffffffc0f3e734 [mlx5_core]
  #6 [ffffa6d14e6b7df8] mlx5e_rep_neigh_update at ffffffffc0f400bb [mlx5_core]
  #7 [ffffa6d14e6b7e50] process_one_work at ffffffffb80acc9c
  #8 [ffffa6d14e6b7ed0] worker_thread at ffffffffb80ad012
  #9 [ffffa6d14e6b7f10] kthread at ffffffffb80b615d
 #10 [ffffa6d14e6b7f50] ret_from_fork at ffffffffb8001b2f

After the first encap is attached, flow will be added to encap
entry's flows list. If neigh update is running at this time, the
following encaps of the flow can't hold the encap_tbl_lock and
sleep. If neigh update thread is waiting for that flow's init_done,
deadlock happens.

Fix it by holding lock outside of the for loop. If neigh update is
running, prevent encap flows from offloading. Since the lock is held
outside of the for loop, concurrent creation of encap entries is not
allowed. So remove unnecessary wait_for_completion call for res_ready.

Fixes: 95435ad ("net/mlx5e: Only access fully initialized flows in neigh update")
Signed-off-by: Chris Mi <[email protected]>
Reviewed-by: Roi Dayan <[email protected]>
Reviewed-by: Vlad Buslov <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
avolmat pushed a commit that referenced this issue Jun 10, 2023
syzkaller found a data race of pkt_sk(sk)->num.

The value is changed under lock_sock() and po->bind_lock, so we
need READ_ONCE() to access pkt_sk(sk)->num without these locks in
packet_bind_spkt(), packet_bind(), and sk_diag_fill().

Note that WRITE_ONCE() is already added by commit c7d2ef5
("net/packet: annotate accesses to po->bind").

BUG: KCSAN: data-race in packet_bind / packet_do_bind

write (marked) to 0xffff88802ffd1cee of 2 bytes by task 7322 on cpu 0:
 packet_do_bind+0x446/0x640 net/packet/af_packet.c:3236
 packet_bind+0x99/0xe0 net/packet/af_packet.c:3321
 __sys_bind+0x19b/0x1e0 net/socket.c:1803
 __do_sys_bind net/socket.c:1814 [inline]
 __se_sys_bind net/socket.c:1812 [inline]
 __x64_sys_bind+0x40/0x50 net/socket.c:1812
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

read to 0xffff88802ffd1cee of 2 bytes by task 7318 on cpu 1:
 packet_bind+0xbf/0xe0 net/packet/af_packet.c:3322
 __sys_bind+0x19b/0x1e0 net/socket.c:1803
 __do_sys_bind net/socket.c:1814 [inline]
 __se_sys_bind net/socket.c:1812 [inline]
 __x64_sys_bind+0x40/0x50 net/socket.c:1812
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

value changed: 0x0300 -> 0x0000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7318 Comm: syz-executor.4 Not tainted 6.3.0-13380-g7fddb5b5300c #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 96ec632 ("packet: Diag core and basic socket info dumping")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzkaller <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
avolmat pushed a commit that referenced this issue Jun 10, 2023
Currently, the per cpu upcall counters are allocated after the vport is
created and inserted into the system. This could lead to the datapath
accessing the counters before they are allocated resulting in a kernel
Oops.

Here is an example:

  PID: 59693    TASK: ffff0005f4f51500  CPU: 0    COMMAND: "ovs-vswitchd"
   #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4
   #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc
   #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60
   #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58
   #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388
   #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c
   #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68
   #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch]
   ...

  PID: 58682    TASK: ffff0005b2f0bf00  CPU: 0    COMMAND: "kworker/0:3"
   #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758
   #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994
   #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8
   #3 [ffff80000a5d3120] die at ffffb70f0628234c
   #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8
   #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4
   #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4
   #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710
   #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74
   #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac
  #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24
  #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc
  torvalds#12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch]
  torvalds#13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch]
  torvalds#14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch]
  torvalds#15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch]
  torvalds#16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch]
  torvalds#17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90

We moved the per cpu upcall counter allocation to the existing vport
alloc and free functions to solve this.

Fixes: 95637d9 ("net: openvswitch: release vport resources on failure")
Fixes: 1933ea3 ("net: openvswitch: Add support to count upcall packets")
Signed-off-by: Eelco Chaudron <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Acked-by: Aaron Conole <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
avolmat pushed a commit that referenced this issue Aug 11, 2023
syzkaller found a bug in unix_bind_bsd() [0].  We can reproduce it
by bind()ing a socket on a path with length 108.

108 is the size of sun_addr of struct sockaddr_un and is the maximum
valid length for the pathname socket.  When calling bind(), we use
struct sockaddr_storage as the actual buffer size, so terminating
sun_addr[108] with null is legitimate as done in unix_mkname_bsd().

However, strlen(sunaddr) for such a case causes fortify_panic() if
CONFIG_FORTIFY_SOURCE=y.  __fortify_strlen() has no idea about the
actual buffer size and see the string as unterminated.

Let's use strnlen() to allow sun_addr to be unterminated at 107.

[0]:
detected buffer overflow in __fortify_strlen
kernel BUG at lib/string_helpers.c:1031!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 255 Comm: syz-executor296 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #4
Hardware name: linux,dummy-virt (DT)
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : fortify_panic+0x1c/0x20 lib/string_helpers.c:1030
lr : fortify_panic+0x1c/0x20 lib/string_helpers.c:1030
sp : ffff800089817af0
x29: ffff800089817af0 x28: ffff800089817b40 x27: 1ffff00011302f68
x26: 000000000000006e x25: 0000000000000012 x24: ffff800087e60140
x23: dfff800000000000 x22: ffff800089817c20 x21: ffff800089817c8e
x20: 000000000000006c x19: ffff00000c323900 x18: ffff800086ab1630
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000001
x14: 1ffff00011302eb8 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 64a26b65474d2a00
x8 : 64a26b65474d2a00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800089817438 x4 : ffff800086ac99e0 x3 : ffff800080f19e8c
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 000000000000002c
Call trace:
 fortify_panic+0x1c/0x20 lib/string_helpers.c:1030
 _Z16__fortify_strlenPKcU25pass_dynamic_object_size1 include/linux/fortify-string.h:217 [inline]
 unix_bind_bsd net/unix/af_unix.c:1212 [inline]
 unix_bind+0xba8/0xc58 net/unix/af_unix.c:1326
 __sys_bind+0x1ac/0x248 net/socket.c:1792
 __do_sys_bind net/socket.c:1803 [inline]
 __se_sys_bind net/socket.c:1801 [inline]
 __arm64_sys_bind+0x7c/0x94 net/socket.c:1801
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x134/0x240 arch/arm64/kernel/syscall.c:139
 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:188
 el0_svc+0x2c/0x7c arch/arm64/kernel/entry-common.c:647
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
Code: aa0003e1 d0000e80 91030000 97ffc91a (d4210000)

Fixes: df8fc4e ("kbuild: Enable -fstrict-flex-arrays=3")
Reported-by: syzkaller <[email protected]>
Suggested-by: Kees Cook <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Simon Horman <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
avolmat pushed a commit that referenced this issue Aug 11, 2023
syzkaller found a warning in packet_getname() [0], where we try to
copy 16 bytes to sockaddr_ll.sll_addr[8].

Some devices (ip6gre, vti6, ip6tnl) have 16 bytes address expressed
by struct in6_addr.  Also, Infiniband has 32 bytes as MAX_ADDR_LEN.

The write seems to overflow, but actually not since we use struct
sockaddr_storage defined in __sys_getsockname() and its size is 128
(_K_SS_MAXSIZE) bytes.  Thus, we have sufficient room after sll_addr[]
as __data[].

To avoid the warning, let's add a flex array member union-ed with
sll_addr.

Another option would be to use strncpy() and limit the copied length
to sizeof(sll_addr), but it will return the partial address and break
an application that passes sockaddr_storage to getsockname().

[0]:
memcpy: detected field-spanning write (size 16) of single field "sll->sll_addr" at net/packet/af_packet.c:3604 (size 8)
WARNING: CPU: 0 PID: 255 at net/packet/af_packet.c:3604 packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
Modules linked in:
CPU: 0 PID: 255 Comm: syz-executor750 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #4
Hardware name: linux,dummy-virt (DT)
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
lr : packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
sp : ffff800089887bc0
x29: ffff800089887bc0 x28: ffff000010f80f80 x27: 0000000000000003
x26: dfff800000000000 x25: ffff700011310f80 x24: ffff800087d55000
x23: dfff800000000000 x22: ffff800089887c2c x21: 0000000000000010
x20: ffff00000de08310 x19: ffff800089887c20 x18: ffff800086ab1630
x17: 20646c6569662065 x16: 6c676e697320666f x15: 0000000000000001
x14: 1fffe0000d56d7ca x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 3e60944c3da92b00
x8 : 3e60944c3da92b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000898874f8 x4 : ffff800086ac99e0 x3 : ffff8000803f8808
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
 __sys_getsockname+0x168/0x24c net/socket.c:2042
 __do_sys_getsockname net/socket.c:2057 [inline]
 __se_sys_getsockname net/socket.c:2054 [inline]
 __arm64_sys_getsockname+0x7c/0x94 net/socket.c:2054
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x134/0x240 arch/arm64/kernel/syscall.c:139
 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:188
 el0_svc+0x2c/0x7c arch/arm64/kernel/entry-common.c:647
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591

Fixes: df8fc4e ("kbuild: Enable -fstrict-flex-arrays=3")
Reported-by: syzkaller <[email protected]>
Suggested-by: Kees Cook <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Simon Horman <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
avolmat pushed a commit that referenced this issue Aug 11, 2023
The cited commit holds encap tbl lock unconditionally when setting
up dests. But it may cause the following deadlock:

 PID: 1063722  TASK: ffffa062ca5d0000  CPU: 13   COMMAND: "handler8"
  #0 [ffffb14de05b7368] __schedule at ffffffffa1d5aa91
  #1 [ffffb14de05b7410] schedule at ffffffffa1d5afdb
  #2 [ffffb14de05b7430] schedule_preempt_disabled at ffffffffa1d5b528
  #3 [ffffb14de05b7440] __mutex_lock at ffffffffa1d5d6cb
  #4 [ffffb14de05b74e8] mutex_lock_nested at ffffffffa1d5ddeb
  #5 [ffffb14de05b74f8] mlx5e_tc_tun_encap_dests_set at ffffffffc12f2096 [mlx5_core]
  #6 [ffffb14de05b7568] post_process_attr at ffffffffc12d9fc5 [mlx5_core]
  #7 [ffffb14de05b75a0] mlx5e_tc_add_fdb_flow at ffffffffc12de877 [mlx5_core]
  #8 [ffffb14de05b75f0] __mlx5e_add_fdb_flow at ffffffffc12e0eef [mlx5_core]
  #9 [ffffb14de05b7660] mlx5e_tc_add_flow at ffffffffc12e12f7 [mlx5_core]
 #10 [ffffb14de05b76b8] mlx5e_configure_flower at ffffffffc12e1686 [mlx5_core]
 #11 [ffffb14de05b7720] mlx5e_rep_indr_offload at ffffffffc12e3817 [mlx5_core]
 torvalds#12 [ffffb14de05b7730] mlx5e_rep_indr_setup_tc_cb at ffffffffc12e388a [mlx5_core]
 torvalds#13 [ffffb14de05b7740] tc_setup_cb_add at ffffffffa1ab2ba8
 torvalds#14 [ffffb14de05b77a0] fl_hw_replace_filter at ffffffffc0bdec2f [cls_flower]
 torvalds#15 [ffffb14de05b7868] fl_change at ffffffffc0be6caa [cls_flower]
 torvalds#16 [ffffb14de05b7908] tc_new_tfilter at ffffffffa1ab71f0

[1031218.028143]  wait_for_completion+0x24/0x30
[1031218.028589]  mlx5e_update_route_decap_flows+0x9a/0x1e0 [mlx5_core]
[1031218.029256]  mlx5e_tc_fib_event_work+0x1ad/0x300 [mlx5_core]
[1031218.029885]  process_one_work+0x24e/0x510

Actually no need to hold encap tbl lock if there is no encap action.
Fix it by checking if encap action exists or not before holding
encap tbl lock.

Fixes: 37c3b9f ("net/mlx5e: Prevent encap offload when neigh update is running")
Signed-off-by: Chris Mi <[email protected]>
Reviewed-by: Vlad Buslov <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
waby38b pushed a commit that referenced this issue Aug 28, 2023
We found below OOB crash:

[   44.211730] ==================================================================
[   44.212045] BUG: KASAN: slab-out-of-bounds in memcmp+0x8b/0xb0
[   44.212045] Read of size 8 at addr ffff88800870f320 by task poc.xfrm/97
[   44.212045]
[   44.212045] CPU: 0 PID: 97 Comm: poc.xfrm Not tainted 6.4.0-rc7-00072-gdad9774deaf1-dirty #4
[   44.212045] Call Trace:
[   44.212045]  <TASK>
[   44.212045]  dump_stack_lvl+0x37/0x50
[   44.212045]  print_report+0xcc/0x620
[   44.212045]  ? __virt_addr_valid+0xf3/0x170
[   44.212045]  ? memcmp+0x8b/0xb0
[   44.212045]  kasan_report+0xb2/0xe0
[   44.212045]  ? memcmp+0x8b/0xb0
[   44.212045]  kasan_check_range+0x39/0x1c0
[   44.212045]  memcmp+0x8b/0xb0
[   44.212045]  xfrm_state_walk+0x21c/0x420
[   44.212045]  ? __pfx_dump_one_state+0x10/0x10
[   44.212045]  xfrm_dump_sa+0x1e2/0x290
[   44.212045]  ? __pfx_xfrm_dump_sa+0x10/0x10
[   44.212045]  ? __kernel_text_address+0xd/0x40
[   44.212045]  ? kasan_unpoison+0x27/0x60
[   44.212045]  ? mutex_lock+0x60/0xe0
[   44.212045]  ? __pfx_mutex_lock+0x10/0x10
[   44.212045]  ? kasan_save_stack+0x22/0x50
[   44.212045]  netlink_dump+0x322/0x6c0
[   44.212045]  ? __pfx_netlink_dump+0x10/0x10
[   44.212045]  ? mutex_unlock+0x7f/0xd0
[   44.212045]  ? __pfx_mutex_unlock+0x10/0x10
[   44.212045]  __netlink_dump_start+0x353/0x430
[   44.212045]  xfrm_user_rcv_msg+0x3a4/0x410
[   44.212045]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[   44.212045]  ? __pfx_xfrm_user_rcv_msg+0x10/0x10
[   44.212045]  ? __pfx_xfrm_dump_sa+0x10/0x10
[   44.212045]  ? __pfx_xfrm_dump_sa_done+0x10/0x10
[   44.212045]  ? __stack_depot_save+0x382/0x4e0
[   44.212045]  ? filter_irq_stacks+0x1c/0x70
[   44.212045]  ? kasan_save_stack+0x32/0x50
[   44.212045]  ? kasan_save_stack+0x22/0x50
[   44.212045]  ? kasan_set_track+0x25/0x30
[   44.212045]  ? __kasan_slab_alloc+0x59/0x70
[   44.212045]  ? kmem_cache_alloc_node+0xf7/0x260
[   44.212045]  ? kmalloc_reserve+0xab/0x120
[   44.212045]  ? __alloc_skb+0xcf/0x210
[   44.212045]  ? netlink_sendmsg+0x509/0x700
[   44.212045]  ? sock_sendmsg+0xde/0xe0
[   44.212045]  ? __sys_sendto+0x18d/0x230
[   44.212045]  ? __x64_sys_sendto+0x71/0x90
[   44.212045]  ? do_syscall_64+0x3f/0x90
[   44.212045]  ? entry_SYSCALL_64_after_hwframe+0x72/0xdc
[   44.212045]  ? netlink_sendmsg+0x509/0x700
[   44.212045]  ? sock_sendmsg+0xde/0xe0
[   44.212045]  ? __sys_sendto+0x18d/0x230
[   44.212045]  ? __x64_sys_sendto+0x71/0x90
[   44.212045]  ? do_syscall_64+0x3f/0x90
[   44.212045]  ? entry_SYSCALL_64_after_hwframe+0x72/0xdc
[   44.212045]  ? kasan_save_stack+0x22/0x50
[   44.212045]  ? kasan_set_track+0x25/0x30
[   44.212045]  ? kasan_save_free_info+0x2e/0x50
[   44.212045]  ? __kasan_slab_free+0x10a/0x190
[   44.212045]  ? kmem_cache_free+0x9c/0x340
[   44.212045]  ? netlink_recvmsg+0x23c/0x660
[   44.212045]  ? sock_recvmsg+0xeb/0xf0
[   44.212045]  ? __sys_recvfrom+0x13c/0x1f0
[   44.212045]  ? __x64_sys_recvfrom+0x71/0x90
[   44.212045]  ? do_syscall_64+0x3f/0x90
[   44.212045]  ? entry_SYSCALL_64_after_hwframe+0x72/0xdc
[   44.212045]  ? copyout+0x3e/0x50
[   44.212045]  netlink_rcv_skb+0xd6/0x210
[   44.212045]  ? __pfx_xfrm_user_rcv_msg+0x10/0x10
[   44.212045]  ? __pfx_netlink_rcv_skb+0x10/0x10
[   44.212045]  ? __pfx_sock_has_perm+0x10/0x10
[   44.212045]  ? mutex_lock+0x8d/0xe0
[   44.212045]  ? __pfx_mutex_lock+0x10/0x10
[   44.212045]  xfrm_netlink_rcv+0x44/0x50
[   44.212045]  netlink_unicast+0x36f/0x4c0
[   44.212045]  ? __pfx_netlink_unicast+0x10/0x10
[   44.212045]  ? netlink_recvmsg+0x500/0x660
[   44.212045]  netlink_sendmsg+0x3b7/0x700
[   44.212045]  ? __pfx_netlink_sendmsg+0x10/0x10
[   44.212045]  ? __pfx_netlink_sendmsg+0x10/0x10
[   44.212045]  sock_sendmsg+0xde/0xe0
[   44.212045]  __sys_sendto+0x18d/0x230
[   44.212045]  ? __pfx___sys_sendto+0x10/0x10
[   44.212045]  ? rcu_core+0x44a/0xe10
[   44.212045]  ? __rseq_handle_notify_resume+0x45b/0x740
[   44.212045]  ? _raw_spin_lock_irq+0x81/0xe0
[   44.212045]  ? __pfx___rseq_handle_notify_resume+0x10/0x10
[   44.212045]  ? __pfx_restore_fpregs_from_fpstate+0x10/0x10
[   44.212045]  ? __pfx_blkcg_maybe_throttle_current+0x10/0x10
[   44.212045]  ? __pfx_task_work_run+0x10/0x10
[   44.212045]  __x64_sys_sendto+0x71/0x90
[   44.212045]  do_syscall_64+0x3f/0x90
[   44.212045]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
[   44.212045] RIP: 0033:0x44b7da
[   44.212045] RSP: 002b:00007ffdc8838548 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[   44.212045] RAX: ffffffffffffffda RBX: 00007ffdc8839978 RCX: 000000000044b7da
[   44.212045] RDX: 0000000000000038 RSI: 00007ffdc8838770 RDI: 0000000000000003
[   44.212045] RBP: 00007ffdc88385b0 R08: 00007ffdc883858c R09: 000000000000000c
[   44.212045] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
[   44.212045] R13: 00007ffdc8839968 R14: 00000000004c37d0 R15: 0000000000000001
[   44.212045]  </TASK>
[   44.212045]
[   44.212045] Allocated by task 97:
[   44.212045]  kasan_save_stack+0x22/0x50
[   44.212045]  kasan_set_track+0x25/0x30
[   44.212045]  __kasan_kmalloc+0x7f/0x90
[   44.212045]  __kmalloc_node_track_caller+0x5b/0x140
[   44.212045]  kmemdup+0x21/0x50
[   44.212045]  xfrm_dump_sa+0x17d/0x290
[   44.212045]  netlink_dump+0x322/0x6c0
[   44.212045]  __netlink_dump_start+0x353/0x430
[   44.212045]  xfrm_user_rcv_msg+0x3a4/0x410
[   44.212045]  netlink_rcv_skb+0xd6/0x210
[   44.212045]  xfrm_netlink_rcv+0x44/0x50
[   44.212045]  netlink_unicast+0x36f/0x4c0
[   44.212045]  netlink_sendmsg+0x3b7/0x700
[   44.212045]  sock_sendmsg+0xde/0xe0
[   44.212045]  __sys_sendto+0x18d/0x230
[   44.212045]  __x64_sys_sendto+0x71/0x90
[   44.212045]  do_syscall_64+0x3f/0x90
[   44.212045]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
[   44.212045]
[   44.212045] The buggy address belongs to the object at ffff88800870f300
[   44.212045]  which belongs to the cache kmalloc-64 of size 64
[   44.212045] The buggy address is located 32 bytes inside of
[   44.212045]  allocated 36-byte region [ffff88800870f300, ffff88800870f324)
[   44.212045]
[   44.212045] The buggy address belongs to the physical page:
[   44.212045] page:00000000e4de16ee refcount:1 mapcount:0 mapping:000000000 ...
[   44.212045] flags: 0x100000000000200(slab|node=0|zone=1)
[   44.212045] page_type: 0xffffffff()
[   44.212045] raw: 0100000000000200 ffff888004c41640 dead000000000122 0000000000000000
[   44.212045] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
[   44.212045] page dumped because: kasan: bad access detected
[   44.212045]
[   44.212045] Memory state around the buggy address:
[   44.212045]  ffff88800870f200: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[   44.212045]  ffff88800870f280: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
[   44.212045] >ffff88800870f300: 00 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc
[   44.212045]                                ^
[   44.212045]  ffff88800870f380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   44.212045]  ffff88800870f400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   44.212045] ==================================================================

By investigating the code, we find the root cause of this OOB is the lack
of checks in xfrm_dump_sa(). The buggy code allows a malicious user to pass
arbitrary value of filter->splen/dplen. Hence, with crafted xfrm states,
the attacker can achieve 8 bytes heap OOB read, which causes info leak.

  if (attrs[XFRMA_ADDRESS_FILTER]) {
    filter = kmemdup(nla_data(attrs[XFRMA_ADDRESS_FILTER]),
        sizeof(*filter), GFP_KERNEL);
    if (filter == NULL)
      return -ENOMEM;
    // NO MORE CHECKS HERE !!!
  }

This patch fixes the OOB by adding necessary boundary checks, just like
the code in pfkey_dump() function.

Fixes: d362309 ("ipsec: add support of limited SA dump")
Signed-off-by: Lin Ma <[email protected]>
Signed-off-by: Steffen Klassert <[email protected]>
waby38b pushed a commit that referenced this issue Mar 12, 2024
Since MOCK_HUGE_PAGE_SIZE was introduced it allows the core code to invoke
mock with large page sizes. This confuses the validation logic that checks
that map/unmap are paired.

This is because the page size computed for map is based on the physical
address and in many cases will always be the base page size, however the
entire range generated by iommufd will be passed to map.

Randomly iommufd can see small groups of physically contiguous pages,
(say 8k unaligned and grouped together), but that group crosses a huge
page boundary. The map side will observe this as a contiguous run and mark
it accordingly, but there is a chance the unmap side will end up
terminating interior huge pages in the middle of that group and trigger a
validation failure. Meaning the validation only works if the core code
passes the iova/length directly from iommufd to mock.

syzkaller randomly hits this with failures like:

  WARNING: CPU: 0 PID: 11568 at drivers/iommu/iommufd/selftest.c:461 mock_domain_unmap_pages+0x1c0/0x250
  Modules linked in:
  CPU: 0 PID: 11568 Comm: syz-executor.0 Not tainted 6.8.0-rc3+ #4
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  RIP: 0010:mock_domain_unmap_pages+0x1c0/0x250
  Code: 2b e8 94 37 0f ff 48 d1 eb 31 ff 48 b8 00 00 00 00 00 00 20 00 48 21 c3 48 89 de e8 aa 32 0f ff 48 85 db 75 07 e8 70 37 0f ff <0f> 0b e8 69 37 0f ff 31 f6 31 ff e8 90 32 0f ff e8 5b 37 0f ff 4c
  RSP: 0018:ffff88800e707490 EFLAGS: 00010293
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff822dfae6
  RDX: ffff88800cf86400 RSI: ffffffff822dfaf0 RDI: 0000000000000007
  RBP: ffff88800e7074d8 R08: 0000000000000000 R09: ffffed1001167c90
  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000001500000
  R13: 0000000000083000 R14: 0000000000000001 R15: 0000000000000800
  FS:  0000555556048480(0000) GS:ffff88806d400000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000001b2dc23000 CR3: 0000000008cbb000 CR4: 0000000000350eb0
  Call Trace:
   <TASK>
   __iommu_unmap+0x281/0x520
   iommu_unmap+0xc9/0x180
   iopt_area_unmap_domain_range+0x1b1/0x290
   iopt_area_unpin_domain+0x590/0x800
   __iopt_area_unfill_domain+0x22e/0x650
   iopt_area_unfill_domain+0x47/0x60
   iopt_unfill_domain+0x187/0x590
   iopt_table_remove_domain+0x267/0x2d0
   iommufd_hwpt_paging_destroy+0x1f1/0x370
   iommufd_object_remove+0x2a3/0x490
   iommufd_device_detach+0x23a/0x2c0
   iommufd_selftest_destroy+0x7a/0xf0
   iommufd_fops_release+0x1d3/0x340
   __fput+0x272/0xb50
   __fput_sync+0x4b/0x60
   __x64_sys_close+0x8b/0x110
   do_syscall_64+0x71/0x140
   entry_SYSCALL_64_after_hwframe+0x46/0x4e

Do the simple thing and just disable the validation when the huge page
tests are being run.

Fixes: 7db521e ("iommufd/selftest: Hugepage mock domain support")
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Joao Martins <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
waby38b pushed a commit that referenced this issue Mar 12, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains fixes for net:

Patch #1 disallows anonymous sets with timeout, except for dynamic sets.
         Anonymous sets with timeouts using the pipapo set backend makes
         no sense from userspace perspective.

Patch #2 rejects constant sets with timeout which has no practical usecase.
         This kind of set, once bound, contains elements that expire but
         no new elements can be added.

Patch #3 restores custom conntrack expectations with NFPROTO_INET,
         from Florian Westphal.

Patch #4 marks rhashtable anonymous set with timeout as dead from the
         commit path to avoid that async GC collects these elements. Rules
         that refers to the anonymous set get released with no mutex held
         from the commit path.

Patch #5 fixes a UBSAN shift overflow in H.323 conntrack helper,
         from Lena Wang.

netfilter pull request 24-03-07

* tag 'nf-24-03-07' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_conntrack_h323: Add protection for bmp length out of range
  netfilter: nf_tables: mark set as dead when unbinding anonymous set with timeout
  netfilter: nft_ct: fix l3num expectations with inet pseudo family
  netfilter: nf_tables: reject constant set with timeout
  netfilter: nf_tables: disallow anonymous set with timeout flag
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
avolmat pushed a commit that referenced this issue Apr 21, 2024
At current x1e80100 interface table, interface #3 is wrongly
connected to DP controller #0 and interface #4 wrongly connected
to DP controller #2. Fix this problem by connect Interface #3 to
DP controller #0 and interface #4 connect to DP controller #1.
Also add interface #6, #7 and #8 connections to DP controller to
complete x1e80100 interface table.

Changs in V3:
-- add v2 changes log

Changs in V2:
-- add x1e80100 to subject
-- add Fixes

Fixes: e3b1f36 ("drm/msm/dpu: Add X1E80100 support")
Signed-off-by: Kuogee Hsieh <[email protected]>
Reviewed-by: Abhinav Kumar <[email protected]>
Reviewed-by: Abel Vesa <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/585549/
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Abhinav Kumar <[email protected]>
avolmat pushed a commit that referenced this issue Apr 21, 2024
Drop support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken without an obvious/easy path forward, and because
exposing adaptive PEBS can leak host LBRs to the guest, i.e. can leak
host kernel addresses to the guest.

Bug #1 is that KVM doesn't account for the upper 32 bits of
IA32_FIXED_CTR_CTRL when (re)programming fixed counters, e.g
fixed_ctrl_field() drops the upper bits, reprogram_fixed_counters()
stores local variables as u8s and truncates the upper bits too, etc.

Bug #2 is that, because KVM _always_ sets precise_ip to a non-zero value
for PEBS events, perf will _always_ generate an adaptive record, even if
the guest requested a basic record.  Note, KVM will also enable adaptive
PEBS in individual *counter*, even if adaptive PEBS isn't exposed to the
guest, but this is benign as MSR_PEBS_DATA_CFG is guaranteed to be zero,
i.e. the guest will only ever see Basic records.

Bug #3 is in perf.  intel_pmu_disable_fixed() doesn't clear the upper
bits either, i.e. leaves ICL_FIXED_0_ADAPTIVE set, and
intel_pmu_enable_fixed() effectively doesn't clear ICL_FIXED_0_ADAPTIVE
either.  I.e. perf _always_ enables ADAPTIVE counters, regardless of what
KVM requests.

Bug #4 is that adaptive PEBS *might* effectively bypass event filters set
by the host, as "Updated Memory Access Info Group" records information
that might be disallowed by userspace via KVM_SET_PMU_EVENT_FILTER.

Bug #5 is that KVM doesn't ensure LBR MSRs hold guest values (or at least
zeros) when entering a vCPU with adaptive PEBS, which allows the guest
to read host LBRs, i.e. host RIPs/addresses, by enabling "LBR Entries"
records.

Disable adaptive PEBS support as an immediate fix due to the severity of
the LBR leak in particular, and because fixing all of the bugs will be
non-trivial, e.g. not suitable for backporting to stable kernels.

Note!  This will break live migration, but trying to make KVM play nice
with live migration would be quite complicated, wouldn't be guaranteed to
work (i.e. KVM might still kill/confuse the guest), and it's not clear
that there are any publicly available VMMs that support adaptive PEBS,
let alone live migrate VMs that support adaptive PEBS, e.g. QEMU doesn't
support PEBS in any capacity.

Link: https://lore.kernel.org/all/[email protected]
Link: https://lore.kernel.org/all/[email protected]
Fixes: c59a1f1 ("KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS")
Cc: [email protected]
Cc: Like Xu <[email protected]>
Cc: Mingwei Zhang <[email protected]>
Cc: Zhenyu Wang <[email protected]>
Cc: Zhang Xiong <[email protected]>
Cc: Lv Zhiyuan <[email protected]>
Cc: Dapeng Mi <[email protected]>
Cc: Jim Mattson <[email protected]>
Acked-by: Like Xu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
avolmat pushed a commit that referenced this issue Apr 21, 2024
…git/netfilter/nf

netfilter pull request 24-04-11

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patches #1 and #2 add missing rcu read side lock when iterating over
expression and object type list which could race with module removal.

Patch #3 prevents promisc packet from visiting the bridge/input hook
	 to amend a recent fix to address conntrack confirmation race
	 in br_netfilter and nf_conntrack_bridge.

Patch #4 adds and uses iterate decorator type to fetch the current
	 pipapo set backend datastructure view when netlink dumps the
	 set elements.

Patch #5 fixes removal of duplicate elements in the pipapo set backend.

Patch #6 flowtable validates pppoe header before accessing it.

Patch #7 fixes flowtable datapath for pppoe packets, otherwise lookup
         fails and pppoe packets follow classic path.
====================

Signed-off-by: David S. Miller <[email protected]>
avolmat pushed a commit that referenced this issue Apr 21, 2024
When I did hard offline test with hugetlb pages, below deadlock occurs:

======================================================
WARNING: possible circular locking dependency detected
6.8.0-11409-gf6cef5f8c37f #1 Not tainted
------------------------------------------------------
bash/46904 is trying to acquire lock:
ffffffffabe68910 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_dec+0x16/0x60

but task is already holding lock:
ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (pcp_batch_high_lock){+.+.}-{3:3}:
       __mutex_lock+0x6c/0x770
       page_alloc_cpu_online+0x3c/0x70
       cpuhp_invoke_callback+0x397/0x5f0
       __cpuhp_invoke_callback_range+0x71/0xe0
       _cpu_up+0xeb/0x210
       cpu_up+0x91/0xe0
       cpuhp_bringup_mask+0x49/0xb0
       bringup_nonboot_cpus+0xb7/0xe0
       smp_init+0x25/0xa0
       kernel_init_freeable+0x15f/0x3e0
       kernel_init+0x15/0x1b0
       ret_from_fork+0x2f/0x50
       ret_from_fork_asm+0x1a/0x30

-> #0 (cpu_hotplug_lock){++++}-{0:0}:
       __lock_acquire+0x1298/0x1cd0
       lock_acquire+0xc0/0x2b0
       cpus_read_lock+0x2a/0xc0
       static_key_slow_dec+0x16/0x60
       __hugetlb_vmemmap_restore_folio+0x1b9/0x200
       dissolve_free_huge_page+0x211/0x260
       __page_handle_poison+0x45/0xc0
       memory_failure+0x65e/0xc70
       hard_offline_page_store+0x55/0xa0
       kernfs_fop_write_iter+0x12c/0x1d0
       vfs_write+0x387/0x550
       ksys_write+0x64/0xe0
       do_syscall_64+0xca/0x1e0
       entry_SYSCALL_64_after_hwframe+0x6d/0x75

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(pcp_batch_high_lock);
                               lock(cpu_hotplug_lock);
                               lock(pcp_batch_high_lock);
  rlock(cpu_hotplug_lock);

 *** DEADLOCK ***

5 locks held by bash/46904:
 #0: ffff98f6c3bb23f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0
 #1: ffff98f6c328e488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0
 #2: ffff98ef83b31890 (kn->active#113){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0
 #3: ffffffffabf9db48 (mf_mutex){+.+.}-{3:3}, at: memory_failure+0x44/0xc70
 #4: ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40

stack backtrace:
CPU: 10 PID: 46904 Comm: bash Kdump: loaded Not tainted 6.8.0-11409-gf6cef5f8c37f #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0xa0
 check_noncircular+0x129/0x140
 __lock_acquire+0x1298/0x1cd0
 lock_acquire+0xc0/0x2b0
 cpus_read_lock+0x2a/0xc0
 static_key_slow_dec+0x16/0x60
 __hugetlb_vmemmap_restore_folio+0x1b9/0x200
 dissolve_free_huge_page+0x211/0x260
 __page_handle_poison+0x45/0xc0
 memory_failure+0x65e/0xc70
 hard_offline_page_store+0x55/0xa0
 kernfs_fop_write_iter+0x12c/0x1d0
 vfs_write+0x387/0x550
 ksys_write+0x64/0xe0
 do_syscall_64+0xca/0x1e0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc862314887
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007fff19311268 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fc862314887
RDX: 000000000000000c RSI: 000056405645fe10 RDI: 0000000000000001
RBP: 000056405645fe10 R08: 00007fc8623d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007fc86241b780 R14: 00007fc862417600 R15: 00007fc862416a00

In short, below scene breaks the lock dependency chain:

 memory_failure
  __page_handle_poison
   zone_pcp_disable -- lock(pcp_batch_high_lock)
   dissolve_free_huge_page
    __hugetlb_vmemmap_restore_folio
     static_key_slow_dec
      cpus_read_lock -- rlock(cpu_hotplug_lock)

Fix this by calling drain_all_pages() instead.

This issue won't occur until commit a6b4085 ("mm: hugetlb: replace
hugetlb_free_vmemmap_enabled with a static_key").  As it introduced
rlock(cpu_hotplug_lock) in dissolve_free_huge_page() code path while
lock(pcp_batch_high_lock) is already in the __page_handle_poison().

[[email protected]: extend comment per Oscar]
[[email protected]: reflow block comment]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: a6b4085 ("mm: hugetlb: replace hugetlb_free_vmemmap_enabled with a static_key")
Signed-off-by: Miaohe Lin <[email protected]>
Acked-by: Oscar Salvador <[email protected]>
Reviewed-by: Jane Chu <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avolmat pushed a commit that referenced this issue Apr 21, 2024
vhost_worker will call tun call backs to receive packets. If too many
illegal packets arrives, tun_do_read will keep dumping packet contents.
When console is enabled, it will costs much more cpu time to dump
packet and soft lockup will be detected.

net_ratelimit mechanism can be used to limit the dumping rate.

PID: 33036    TASK: ffff949da6f20000  CPU: 23   COMMAND: "vhost-32980"
 #0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253
 #1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3
 #2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e
 #3 [fffffe00003fced0] do_nmi at ffffffff8922660d
 #4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663
    [exception RIP: io_serial_in+20]
    RIP: ffffffff89792594  RSP: ffffa655314979e8  RFLAGS: 00000002
    RAX: ffffffff89792500  RBX: ffffffff8af428a0  RCX: 0000000000000000
    RDX: 00000000000003fd  RSI: 0000000000000005  RDI: ffffffff8af428a0
    RBP: 0000000000002710   R8: 0000000000000004   R9: 000000000000000f
    R10: 0000000000000000  R11: ffffffff8acbf64f  R12: 0000000000000020
    R13: ffffffff8acbf698  R14: 0000000000000058  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #5 [ffffa655314979e8] io_serial_in at ffffffff89792594
 #6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470
 #7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6
 #8 [ffffa65531497a20] uart_console_write at ffffffff8978b605
 #9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558
 #10 [ffffa65531497ac8] console_unlock at ffffffff89316124
 #11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07
 torvalds#12 [ffffa65531497b68] printk at ffffffff89318306
 torvalds#13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765
 torvalds#14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun]
 torvalds#15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun]
 torvalds#16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net]
 torvalds#17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost]
 torvalds#18 [ffffa65531497f10] kthread at ffffffff892d2e72
 torvalds#19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f

Fixes: ef3db4a ("tun: avoid BUG, dump packet on GSO errors")
Signed-off-by: Lei Chen <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Acked-by: Jason Wang <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
avolmat pushed a commit that referenced this issue Jun 2, 2024
…git/netfilter/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

Patch #1 syzbot reports that nf_reinject() could be called without
         rcu_read_lock() when flushing pending packets at nfnetlink
         queue removal, from Eric Dumazet.

Patch #2 flushes ipset list:set when canceling garbage collection to
         reference to other lists to fix a race, from Jozsef Kadlecsik.

Patch #3 restores q-in-q matching with nft_payload by reverting
         f6ae9f1 ("netfilter: nft_payload: add C-VLAN support").

Patch #4 fixes vlan mangling in skbuff when vlan offload is present
         in skbuff, without this patch nft_payload corrupts packets
         in this case.

Patch #5 fixes possible nul-deref in tproxy no IP address is found in
         netdevice, reported by syzbot and patch from Florian Westphal.

Patch #6 removes a superfluous restriction which prevents loose fib
         lookups from input and forward hooks, from Eric Garver.

My assessment is that patches #1, #2 and #5 address possible kernel
crash, anything else in this batch fixes broken features.

netfilter pull request 24-05-29

* tag 'nf-24-05-29' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_fib: allow from forward/input without iif selector
  netfilter: tproxy: bail out if IP has been disabled on the device
  netfilter: nft_payload: skbuff vlan metadata mangle support
  netfilter: nft_payload: restore vlan q-in-q match support
  netfilter: ipset: Add list flush to cancel_gc
  netfilter: nfnetlink_queue: acquire rcu_read_lock() in instance_destroy_rcu()
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jul 2, 2024
Michael Chan says:

====================
bnxt_en: PTP updates for net-next

The first 5 patches implement the PTP feature on the new BCM5760X
chips.  The main new hardware feature is the new TX timestamp
completion which enables the driver to retrieve the TX timestamp
in NAPI without deferring to the PTP worker.

The last 5 patches increase the number of TX PTP packets in-flight
from 1 to 4 on the older BCM5750X chips.  On these older chips, we
need to call firmware in the PTP worker to retrieve the timestamp.
We use an arry to keep track of the in-flight TX PTP packets.

v2: Patch #2: Fix the unwind of txr->is_ts_pkt when bnxt_start_xmit() aborts.
    Patch #4: Set the SKBTX_IN_PROGRESS flag for timestamp packets.
====================

Signed-off-by: David S. Miller <[email protected]>
avolmat pushed a commit that referenced this issue Jan 9, 2025
syzbot reports that a recent fix causes nesting issues between the (now)
raw timeoutlock and the eventfd locking:

=============================
[ BUG: Invalid wait context ]
6.13.0-rc4-00080-g9828a4c0901f torvalds#29 Not tainted
-----------------------------
kworker/u32:0/68094 is trying to lock:
ffff000014d7a520 (&ctx->wqh#2){..-.}-{3:3}, at: eventfd_signal_mask+0x64/0x180
other info that might help us debug this:
context-{5:5}
6 locks held by kworker/u32:0/68094:
 #0: ffff0000c1d98148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x4e8/0xfc0
 #1: ffff80008d927c78 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x53c/0xfc0
 #2: ffff0000c59bc3d8 (&ctx->completion_lock){+.+.}-{3:3}, at: io_kill_timeouts+0x40/0x180
 #3: ffff0000c59bc358 (&ctx->timeout_lock){-.-.}-{2:2}, at: io_kill_timeouts+0x48/0x180
 #4: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38
 #5: ffff800085127aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x8/0x38
stack backtrace:
CPU: 7 UID: 0 PID: 68094 Comm: kworker/u32:0 Not tainted 6.13.0-rc4-00080-g9828a4c0901f torvalds#29
Hardware name: linux,dummy-virt (DT)
Workqueue: iou_exit io_ring_exit_work
Call trace:
 show_stack+0x1c/0x30 (C)
 __dump_stack+0x24/0x30
 dump_stack_lvl+0x60/0x80
 dump_stack+0x14/0x20
 __lock_acquire+0x19f8/0x60c8
 lock_acquire+0x1a4/0x540
 _raw_spin_lock_irqsave+0x90/0xd0
 eventfd_signal_mask+0x64/0x180
 io_eventfd_signal+0x64/0x108
 io_req_local_work_add+0x294/0x430
 __io_req_task_work_add+0x1c0/0x270
 io_kill_timeout+0x1f0/0x288
 io_kill_timeouts+0xd4/0x180
 io_uring_try_cancel_requests+0x2e8/0x388
 io_ring_exit_work+0x150/0x550
 process_one_work+0x5e8/0xfc0
 worker_thread+0x7ec/0xc80
 kthread+0x24c/0x300
 ret_from_fork+0x10/0x20

because after the preempt-rt fix for the timeout lock nesting inside
the io-wq lock, we now have the eventfd spinlock nesting inside the
raw timeout spinlock.

Rather than play whack-a-mole with other nesting on the timeout lock,
split the deletion and killing of timeouts so queueing the task_work
for the timeout cancelations can get done outside of the timeout lock.

Reported-by: [email protected]
Fixes: 020b40f ("io_uring: make ctx->timeout_lock a raw spinlock")
Signed-off-by: Jens Axboe <[email protected]>
avolmat pushed a commit that referenced this issue Jan 9, 2025
…le_direct_reclaim()

The task sometimes continues looping in throttle_direct_reclaim() because
allow_direct_reclaim(pgdat) keeps returning false.  

 #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac
 #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c
 #2 [ffff80002cb6f990] schedule at ffff800008abc50c
 #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550
 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68
 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660
 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98
 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8
 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974
 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4

At this point, the pgdat contains the following two zones:

        NODE: 4  ZONE: 0  ADDR: ffff00817fffe540  NAME: "DMA32"
          SIZE: 20480  MIN/LOW/HIGH: 11/28/45
          VM_STAT:
                NR_FREE_PAGES: 359
        NR_ZONE_INACTIVE_ANON: 18813
          NR_ZONE_ACTIVE_ANON: 0
        NR_ZONE_INACTIVE_FILE: 50
          NR_ZONE_ACTIVE_FILE: 0
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

        NODE: 4  ZONE: 1  ADDR: ffff00817fffec00  NAME: "Normal"
          SIZE: 8454144  PRESENT: 98304  MIN/LOW/HIGH: 68/166/264
          VM_STAT:
                NR_FREE_PAGES: 146
        NR_ZONE_INACTIVE_ANON: 94668
          NR_ZONE_ACTIVE_ANON: 3
        NR_ZONE_INACTIVE_FILE: 735
          NR_ZONE_ACTIVE_FILE: 78
          NR_ZONE_UNEVICTABLE: 0
        NR_ZONE_WRITE_PENDING: 0
                     NR_MLOCK: 0
                    NR_BOUNCE: 0
                   NR_ZSPAGES: 0
            NR_FREE_CMA_PAGES: 0

In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of
inactive/active file-backed pages calculated in zone_reclaimable_pages()
based on the result of zone_page_state_snapshot() is zero.  

Additionally, since this system lacks swap, the calculation of inactive/
active anonymous pages is skipped.

        crash> p nr_swap_pages
        nr_swap_pages = $1937 = {
          counter = 0
        }

As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to
the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having
free pages significantly exceeding the high watermark.

The problem is that the pgdat->kswapd_failures hasn't been incremented.

        crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures
        $1935 = 0x0

This is because the node deemed balanced.  The node balancing logic in
balance_pgdat() evaluates all zones collectively.  If one or more zones
(e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the
entire node is deemed balanced.  This causes balance_pgdat() to exit early
before incrementing the kswapd_failures, as it considers the overall
memory state acceptable, even though some zones (like ZONE_NORMAL) remain
under significant pressure.


The patch ensures that zone_reclaimable_pages() includes free pages
(NR_FREE_PAGES) in its calculation when no other reclaimable pages are
available (e.g., file-backed or anonymous pages).  This change prevents
zones like ZONE_DMA32, which have sufficient free pages, from being
mistakenly deemed unreclaimable.  By doing so, the patch ensures proper
node balancing, avoids masking pressure on other zones like ZONE_NORMAL,
and prevents infinite loops in throttle_direct_reclaim() caused by
allow_direct_reclaim(pgdat) repeatedly returning false.


The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused
by a node being incorrectly deemed balanced despite pressure in certain
zones, such as ZONE_NORMAL.  This issue arises from
zone_reclaimable_pages() returning 0 for zones without reclaimable file-
backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient
free pages to be skipped.

The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored
during reclaim, masking pressure in other zones.  Consequently,
pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback
mechanisms in allow_direct_reclaim() from being triggered, leading to an
infinite loop in throttle_direct_reclaim().

This patch modifies zone_reclaimable_pages() to account for free pages
(NR_FREE_PAGES) when no other reclaimable pages exist.  This ensures zones
with sufficient free pages are not skipped, enabling proper balancing and
reclaim behavior.

[[email protected]: coding-style cleanups]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations")
Signed-off-by: Seiji Nishikawa <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
avolmat pushed a commit that referenced this issue Jan 9, 2025
…nt message

Address a bug in the kernel that triggers a "sleeping function called from
invalid context" warning when /sys/kernel/debug/kmemleak is printed under
specific conditions:
- CONFIG_PREEMPT_RT=y
- Set SELinux as the LSM for the system
- Set kptr_restrict to 1
- kmemleak buffer contains at least one item

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 136, name: cat
preempt_count: 1, expected: 0
RCU nest depth: 2, expected: 2
6 locks held by cat/136:
 #0: ffff32e64bcbf950 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb8/0xe30
 #1: ffffafe6aaa9dea0 (scan_mutex){+.+.}-{3:3}, at: kmemleak_seq_start+0x34/0x128
 #3: ffff32e6546b1cd0 (&object->lock){....}-{2:2}, at: kmemleak_seq_show+0x3c/0x1e0
 #4: ffffafe6aa8d8560 (rcu_read_lock){....}-{1:2}, at: has_ns_capability_noaudit+0x8/0x1b0
 #5: ffffafe6aabbc0f8 (notif_lock){+.+.}-{2:2}, at: avc_compute_av+0xc4/0x3d0
irq event stamp: 136660
hardirqs last  enabled at (136659): [<ffffafe6a80fd7a0>] _raw_spin_unlock_irqrestore+0xa8/0xd8
hardirqs last disabled at (136660): [<ffffafe6a80fd85c>] _raw_spin_lock_irqsave+0x8c/0xb0
softirqs last  enabled at (0): [<ffffafe6a5d50b28>] copy_process+0x11d8/0x3df8
softirqs last disabled at (0): [<0000000000000000>] 0x0
Preemption disabled at:
[<ffffafe6a6598a4c>] kmemleak_seq_show+0x3c/0x1e0
CPU: 1 UID: 0 PID: 136 Comm: cat Tainted: G            E      6.11.0-rt7+ torvalds#34
Tainted: [E]=UNSIGNED_MODULE
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0xa0/0x128
 show_stack+0x1c/0x30
 dump_stack_lvl+0xe8/0x198
 dump_stack+0x18/0x20
 rt_spin_lock+0x8c/0x1a8
 avc_perm_nonode+0xa0/0x150
 cred_has_capability.isra.0+0x118/0x218
 selinux_capable+0x50/0x80
 security_capable+0x7c/0xd0
 has_ns_capability_noaudit+0x94/0x1b0
 has_capability_noaudit+0x20/0x30
 restricted_pointer+0x21c/0x4b0
 pointer+0x298/0x760
 vsnprintf+0x330/0xf70
 seq_printf+0x178/0x218
 print_unreferenced+0x1a4/0x2d0
 kmemleak_seq_show+0xd0/0x1e0
 seq_read_iter+0x354/0xe30
 seq_read+0x250/0x378
 full_proxy_read+0xd8/0x148
 vfs_read+0x190/0x918
 ksys_read+0xf0/0x1e0
 __arm64_sys_read+0x70/0xa8
 invoke_syscall.constprop.0+0xd4/0x1d8
 el0_svc+0x50/0x158
 el0t_64_sync+0x17c/0x180

%pS and %pK, in the same back trace line, are redundant, and %pS can void
%pK service in certain contexts.

%pS alone already provides the necessary information, and if it cannot
resolve the symbol, it falls back to printing the raw address voiding
the original intent behind the %pK.

Additionally, %pK requires a privilege check CAP_SYSLOG enforced through
the LSM, which can trigger a "sleeping function called from invalid
context" warning under RT_PREEMPT kernels when the check occurs in an
atomic context. This issue may also affect other LSMs.

This change avoids the unnecessary privilege check and resolves the
sleeping function warning without any loss of information.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 3a6f33d ("mm/kmemleak: use %pK to display kernel pointers in backtrace")
Signed-off-by: Alessandro Carminati <[email protected]>
Acked-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Cc: Clément Léger <[email protected]>
Cc: Alessandro Carminati <[email protected]>
Cc: Eric Chanudet <[email protected]>
Cc: Gabriele Paoloni <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Weißschuh <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jan 20, 2025
Tariq Toukan says:

====================
net/mlx5e: CT: Add support for hardware steering

This series start with one more HWS patch by Yevgeny, followed by
patches that add support for connection tracking in hardware steering
mode. It consists of:
- patch #2 hooks up the CT ops for the new mode in the right places.
- patch #3 moves a function into a common file, so it can be reused.
- patch #4 uses the HWS API to implement connection tracking.

The main advantage of hardware steering compared to software steering is
vastly improved performance when adding/removing/updating rules.  Using
the T-Rex traffic generator to initiate multi-million UDP flows per
second, a kernel running with these patches was able to offload ~600K
unique UDP flows per second, a number around ~7x larger than software
steering was able to achieve on the same hardware (256-thread AMD EPYC,
512 GB RAM, ConnectX 7 b2b).
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jan 20, 2025
This fixes the following hard lockup in isolate_lru_folios() during memory
reclaim.  If the LRU mostly contains ineligible folios this may trigger
watchdog.

watchdog: Watchdog detected hard LOCKUP on cpu 173
RIP: 0010:native_queued_spin_lock_slowpath+0x255/0x2a0
Call Trace:
	_raw_spin_lock_irqsave+0x31/0x40
	folio_lruvec_lock_irqsave+0x5f/0x90
	folio_batch_move_lru+0x91/0x150
	lru_add_drain_per_cpu+0x1c/0x40
	process_one_work+0x17d/0x350
	worker_thread+0x27b/0x3a0
	kthread+0xe8/0x120
	ret_from_fork+0x34/0x50
	ret_from_fork_asm+0x1b/0x30

lruvec->lru_lock owner:

PID: 2865     TASK: ffff888139214d40  CPU: 40   COMMAND: "kswapd0"
 #0 [fffffe0000945e60] crash_nmi_callback at ffffffffa567a555
 #1 [fffffe0000945e68] nmi_handle at ffffffffa563b171
 #2 [fffffe0000945eb0] default_do_nmi at ffffffffa6575920
 #3 [fffffe0000945ed0] exc_nmi at ffffffffa6575af4
 #4 [fffffe0000945ef0] end_repeat_nmi at ffffffffa6601dde
    [exception RIP: isolate_lru_folios+403]
    RIP: ffffffffa597df53  RSP: ffffc90006fb7c28  RFLAGS: 00000002
    RAX: 0000000000000001  RBX: ffffc90006fb7c60  RCX: ffffea04a2196f88
    RDX: ffffc90006fb7c60  RSI: ffffc90006fb7c60  RDI: ffffea04a2197048
    RBP: ffff88812cbd3010   R8: ffffea04a2197008   R9: 0000000000000001
    R10: 0000000000000000  R11: 0000000000000001  R12: ffffea04a2197008
    R13: ffffea04a2197048  R14: ffffc90006fb7de8  R15: 0000000003e3e937
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <NMI exception stack>
 #5 [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
 #6 [ffffc90006fb7cf8] shrink_active_list at ffffffffa597f788
 #7 [ffffc90006fb7da8] balance_pgdat at ffffffffa5986db0
 #8 [ffffc90006fb7ec0] kswapd at ffffffffa5987354
 #9 [ffffc90006fb7ef8] kthread at ffffffffa5748238
crash>

Scenario:
User processe are requesting a large amount of memory and keep page active.
Then a module continuously requests memory from ZONE_DMA32 area.
Memory reclaim will be triggered due to ZONE_DMA32 watermark alarm reached.
However pages in the LRU(active_anon) list are mostly from
the ZONE_NORMAL area.

Reproduce:
Terminal 1: Construct to continuously increase pages active(anon).
mkdir /tmp/memory
mount -t tmpfs -o size=1024000M tmpfs /tmp/memory
dd if=/dev/zero of=/tmp/memory/block bs=4M
tail /tmp/memory/block

Terminal 2:
vmstat -a 1
active will increase.
procs ---memory--- ---swap-- ---io---- -system-- ---cpu--- ...
 r  b   swpd   free  inact active   si   so    bi    bo
 1  0   0 1445623076 45898836 83646008    0    0     0
 1  0   0 1445623076 43450228 86094616    0    0     0
 1  0   0 1445623076 41003480 88541364    0    0     0
 1  0   0 1445623076 38557088 90987756    0    0     0
 1  0   0 1445623076 36109688 93435156    0    0     0
 1  0   0 1445619552 33663256 95881632    0    0     0
 1  0   0 1445619804 31217140 98327792    0    0     0
 1  0   0 1445619804 28769988 100774944    0    0     0
 1  0   0 1445619804 26322348 103222584    0    0     0
 1  0   0 1445619804 23875592 105669340    0    0     0

cat /proc/meminfo | head
Active(anon) increase.
MemTotal:       1579941036 kB
MemFree:        1445618500 kB
MemAvailable:   1453013224 kB
Buffers:            6516 kB
Cached:         128653956 kB
SwapCached:            0 kB
Active:         118110812 kB
Inactive:       11436620 kB
Active(anon):   115345744 kB
Inactive(anon):   945292 kB

When the Active(anon) is 115345744 kB, insmod module triggers
the ZONE_DMA32 watermark.

perf record -e vmscan:mm_vmscan_lru_isolate -aR
perf script
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=2
nr_skipped=2 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=29
nr_skipped=29 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon

See nr_scanned=28835844.
28835844 * 4k = 115343376KB approximately equal to 115345744 kB.

If increase Active(anon) to 1000G then insmod module triggers
the ZONE_DMA32 watermark. hard lockup will occur.

In my device nr_scanned = 0000000003e3e937 when hard lockup.
Convert to memory size 0x0000000003e3e937 * 4KB = 261072092 KB.

   [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
    ffffc90006fb7c30: 0000000000000020 0000000000000000
    ffffc90006fb7c40: ffffc90006fb7d40 ffff88812cbd3000
    ffffc90006fb7c50: ffffc90006fb7d30 0000000106fb7de8
    ffffc90006fb7c60: ffffea04a2197008 ffffea0006ed4a48
    ffffc90006fb7c70: 0000000000000000 0000000000000000
    ffffc90006fb7c80: 0000000000000000 0000000000000000
    ffffc90006fb7c90: 0000000000000000 0000000000000000
    ffffc90006fb7ca0: 0000000000000000 0000000003e3e937
    ffffc90006fb7cb0: 0000000000000000 0000000000000000
    ffffc90006fb7cc0: 8d7c0b56b7874b00 ffff88812cbd3000

About the Fixes:
Why did it take eight years to be discovered?

The problem requires the following conditions to occur:
1. The device memory should be large enough.
2. Pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area.
3. The memory in ZONE_DMA32 needs to reach the watermark.

If the memory is not large enough, or if the usage design of ZONE_DMA32
area memory is reasonable, this problem is difficult to detect.

notes:
The problem is most likely to occur in ZONE_DMA32 and ZONE_NORMAL,
but other suitable scenarios may also trigger the problem.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b2e1875 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Signed-off-by: liuye <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jan 20, 2025
Attempt to enable IPsec packet offload in tunnel mode in debug kernel
generates the following kernel panic, which is happening due to two
issues:
1. In SA add section, the should be _bh() variant when marking SA mode.
2. There is not needed flush_workqueue in SA delete routine. It is not
needed as at this stage as it is removed from SADB and the running work
will be canceled later in SA free.

 =====================================================
 WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
 6.12.0+ #4 Not tainted
 -----------------------------------------------------
 charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire:
 ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]

 and this task is already holding:
 ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30
 which would create a new lock dependency:
  (&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3}

 but this new dependency connects a SOFTIRQ-irq-safe lock:
  (&x->lock){+.-.}-{3:3}

 ... which became SOFTIRQ-irq-safe at:
   lock_acquire+0x1be/0x520
   _raw_spin_lock_bh+0x34/0x40
   xfrm_timer_handler+0x91/0xd70
   __hrtimer_run_queues+0x1dd/0xa60
   hrtimer_run_softirq+0x146/0x2e0
   handle_softirqs+0x266/0x860
   irq_exit_rcu+0x115/0x1a0
   sysvec_apic_timer_interrupt+0x6e/0x90
   asm_sysvec_apic_timer_interrupt+0x16/0x20
   default_idle+0x13/0x20
   default_idle_call+0x67/0xa0
   do_idle+0x2da/0x320
   cpu_startup_entry+0x50/0x60
   start_secondary+0x213/0x2a0
   common_startup_64+0x129/0x138

 to a SOFTIRQ-irq-unsafe lock:
  (&xa->xa_lock#24){+.+.}-{3:3}

 ... which became SOFTIRQ-irq-unsafe at:
 ...
   lock_acquire+0x1be/0x520
   _raw_spin_lock+0x2c/0x40
   xa_set_mark+0x70/0x110
   mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
   xfrm_dev_state_add+0x3bb/0xd70
   xfrm_add_sa+0x2451/0x4a90
   xfrm_user_rcv_msg+0x493/0x880
   netlink_rcv_skb+0x12e/0x380
   xfrm_netlink_rcv+0x6d/0x90
   netlink_unicast+0x42f/0x740
   netlink_sendmsg+0x745/0xbe0
   __sock_sendmsg+0xc5/0x190
   __sys_sendto+0x1fe/0x2c0
   __x64_sys_sendto+0xdc/0x1b0
   do_syscall_64+0x6d/0x140
   entry_SYSCALL_64_after_hwframe+0x4b/0x53

 other info that might help us debug this:

  Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&xa->xa_lock#24);
                                local_irq_disable();
                                lock(&x->lock);
                                lock(&xa->xa_lock#24);
   <Interrupt>
     lock(&x->lock);

  *** DEADLOCK ***

 2 locks held by charon/1337:
  #0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90
  #1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30

 the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
 -> (&x->lock){+.-.}-{3:3} ops: 29 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_alloc_spi+0xc0/0xe60
                     xfrm_alloc_userspi+0x5f6/0xbc0
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    IN-SOFTIRQ-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     xfrm_timer_handler+0x91/0xd70
                     __hrtimer_run_queues+0x1dd/0xa60
                     hrtimer_run_softirq+0x146/0x2e0
                     handle_softirqs+0x266/0x860
                     irq_exit_rcu+0x115/0x1a0
                     sysvec_apic_timer_interrupt+0x6e/0x90
                     asm_sysvec_apic_timer_interrupt+0x16/0x20
                     default_idle+0x13/0x20
                     default_idle_call+0x67/0xa0
                     do_idle+0x2da/0x320
                     cpu_startup_entry+0x50/0x60
                     start_secondary+0x213/0x2a0
                     common_startup_64+0x129/0x138
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    xfrm_alloc_spi+0xc0/0xe60
                    xfrm_alloc_userspi+0x5f6/0xbc0
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffff87f9cd20>] __key.18+0x0/0x40

 the dependencies between the lock to be acquired
  and SOFTIRQ-irq-unsafe lock:
 -> (&xa->xa_lock#24){+.+.}-{3:3} ops: 9 {
    HARDIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock_bh+0x34/0x40
                     mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    SOFTIRQ-ON-W at:
                     lock_acquire+0x1be/0x520
                     _raw_spin_lock+0x2c/0x40
                     xa_set_mark+0x70/0x110
                     mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
                     xfrm_dev_state_add+0x3bb/0xd70
                     xfrm_add_sa+0x2451/0x4a90
                     xfrm_user_rcv_msg+0x493/0x880
                     netlink_rcv_skb+0x12e/0x380
                     xfrm_netlink_rcv+0x6d/0x90
                     netlink_unicast+0x42f/0x740
                     netlink_sendmsg+0x745/0xbe0
                     __sock_sendmsg+0xc5/0x190
                     __sys_sendto+0x1fe/0x2c0
                     __x64_sys_sendto+0xdc/0x1b0
                     do_syscall_64+0x6d/0x140
                     entry_SYSCALL_64_after_hwframe+0x4b/0x53
    INITIAL USE at:
                    lock_acquire+0x1be/0x520
                    _raw_spin_lock_bh+0x34/0x40
                    mlx5e_xfrm_add_state+0xc5b/0x2290 [mlx5_core]
                    xfrm_dev_state_add+0x3bb/0xd70
                    xfrm_add_sa+0x2451/0x4a90
                    xfrm_user_rcv_msg+0x493/0x880
                    netlink_rcv_skb+0x12e/0x380
                    xfrm_netlink_rcv+0x6d/0x90
                    netlink_unicast+0x42f/0x740
                    netlink_sendmsg+0x745/0xbe0
                    __sock_sendmsg+0xc5/0x190
                    __sys_sendto+0x1fe/0x2c0
                    __x64_sys_sendto+0xdc/0x1b0
                    do_syscall_64+0x6d/0x140
                    entry_SYSCALL_64_after_hwframe+0x4b/0x53
  }
  ... key      at: [<ffffffffa078ff60>] __key.48+0x0/0xfffffffffff210a0 [mlx5_core]
  ... acquired at:
    __lock_acquire+0x30a0/0x5040
    lock_acquire+0x1be/0x520
    _raw_spin_lock_bh+0x34/0x40
    mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
    xfrm_dev_state_delete+0x90/0x160
    __xfrm_state_delete+0x662/0xae0
    xfrm_state_delete+0x1e/0x30
    xfrm_del_sa+0x1c2/0x340
    xfrm_user_rcv_msg+0x493/0x880
    netlink_rcv_skb+0x12e/0x380
    xfrm_netlink_rcv+0x6d/0x90
    netlink_unicast+0x42f/0x740
    netlink_sendmsg+0x745/0xbe0
    __sock_sendmsg+0xc5/0x190
    __sys_sendto+0x1fe/0x2c0
    __x64_sys_sendto+0xdc/0x1b0
    do_syscall_64+0x6d/0x140
    entry_SYSCALL_64_after_hwframe+0x4b/0x53

 stack backtrace:
 CPU: 7 UID: 0 PID: 1337 Comm: charon Not tainted 6.12.0+ #4
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x74/0xd0
  check_irq_usage+0x12e8/0x1d90
  ? print_shortest_lock_dependencies_backwards+0x1b0/0x1b0
  ? check_chain_key+0x1bb/0x4c0
  ? __lockdep_reset_lock+0x180/0x180
  ? check_path.constprop.0+0x24/0x50
  ? mark_lock+0x108/0x2fb0
  ? print_circular_bug+0x9b0/0x9b0
  ? mark_lock+0x108/0x2fb0
  ? print_usage_bug.part.0+0x670/0x670
  ? check_prev_add+0x1c4/0x2310
  check_prev_add+0x1c4/0x2310
  __lock_acquire+0x30a0/0x5040
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  lock_acquire+0x1be/0x520
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  ? lockdep_hardirqs_on_prepare+0x400/0x400
  ? __xfrm_state_delete+0x5f0/0xae0
  ? lock_downgrade+0x6b0/0x6b0
  _raw_spin_lock_bh+0x34/0x40
  ? mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
  xfrm_dev_state_delete+0x90/0x160
  __xfrm_state_delete+0x662/0xae0
  xfrm_state_delete+0x1e/0x30
  xfrm_del_sa+0x1c2/0x340
  ? xfrm_get_sa+0x250/0x250
  ? check_chain_key+0x1bb/0x4c0
  xfrm_user_rcv_msg+0x493/0x880
  ? copy_sec_ctx+0x270/0x270
  ? check_chain_key+0x1bb/0x4c0
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  ? lockdep_set_lock_cmp_fn+0x190/0x190
  netlink_rcv_skb+0x12e/0x380
  ? copy_sec_ctx+0x270/0x270
  ? netlink_ack+0xd90/0xd90
  ? netlink_deliver_tap+0xcd/0xb60
  xfrm_netlink_rcv+0x6d/0x90
  netlink_unicast+0x42f/0x740
  ? netlink_attachskb+0x730/0x730
  ? lock_acquire+0x1be/0x520
  netlink_sendmsg+0x745/0xbe0
  ? netlink_unicast+0x740/0x740
  ? __might_fault+0xbb/0x170
  ? netlink_unicast+0x740/0x740
  __sock_sendmsg+0xc5/0x190
  ? fdget+0x163/0x1d0
  __sys_sendto+0x1fe/0x2c0
  ? __x64_sys_getpeername+0xb0/0xb0
  ? do_user_addr_fault+0x856/0xe30
  ? lock_acquire+0x1be/0x520
  ? __task_pid_nr_ns+0x117/0x410
  ? lock_downgrade+0x6b0/0x6b0
  __x64_sys_sendto+0xdc/0x1b0
  ? lockdep_hardirqs_on_prepare+0x284/0x400
  do_syscall_64+0x6d/0x140
  entry_SYSCALL_64_after_hwframe+0x4b/0x53
 RIP: 0033:0x7f7d31291ba4
 Code: 7d e8 89 4d d4 e8 4c 42 f7 ff 44 8b 4d d0 4c 8b 45 c8 89 c3 44 8b 55 d4 8b 7d e8 b8 2c 00 00 00 48 8b 55 d8 48 8b 75 e0 0f 05 <48> 3d 00 f0 ff ff 77 34 89 df 48 89 45 e8 e8 99 42 f7 ff 48 8b 45
 RSP: 002b:00007f7d2ccd94f0 EFLAGS: 00000297 ORIG_RAX: 000000000000002c
 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f7d31291ba4
 RDX: 0000000000000028 RSI: 00007f7d2ccd96a0 RDI: 000000000000000a
 RBP: 00007f7d2ccd9530 R08: 00007f7d2ccd9598 R09: 000000000000000c
 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000028
 R13: 00007f7d2ccd9598 R14: 00007f7d2ccd96a0 R15: 00000000000000e1
  </TASK>

Fixes: 4c24272 ("net/mlx5e: Listen to ARP events to update IPsec L2 headers in tunnel mode")
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jan 23, 2025
This commit addresses a circular locking dependency issue within the GFX
isolation mechanism. The problem was identified by a warning indicating
a potential deadlock due to inconsistent lock acquisition order.

- The `amdgpu_gfx_enforce_isolation_ring_begin_use` and
  `amdgpu_gfx_enforce_isolation_ring_end_use` functions previously
  acquired `enforce_isolation_mutex` and called `amdgpu_gfx_kfd_sch_ctrl`,
  leading to potential deadlocks. ie., If `amdgpu_gfx_kfd_sch_ctrl` is
  called while `enforce_isolation_mutex` is held, and
  `amdgpu_gfx_enforce_isolation_handler` is called while `kfd_sch_mutex` is
  held, it can create a circular dependency.

By ensuring consistent lock usage, this fix resolves the issue:

[  606.297333] ======================================================
[  606.297343] WARNING: possible circular locking dependency detected
[  606.297353] 6.10.0-amd-mlkd-610-311224-lof torvalds#19 Tainted: G           OE
[  606.297365] ------------------------------------------------------
[  606.297375] kworker/u96:3/3825 is trying to acquire lock:
[  606.297385] ffff9aa64e431cb8 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}, at: __flush_work+0x232/0x610
[  606.297413]
               but task is already holding lock:
[  606.297423] ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.297725]
               which lock already depends on the new lock.

[  606.297738]
               the existing dependency chain (in reverse order) is:
[  606.297749]
               -> #2 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}:
[  606.297765]        __mutex_lock+0x85/0x930
[  606.297776]        mutex_lock_nested+0x1b/0x30
[  606.297786]        amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.298007]        amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.298225]        amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.298412]        amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.298603]        amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.298866]        drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.298880]        process_one_work+0x21e/0x680
[  606.298890]        worker_thread+0x190/0x350
[  606.298899]        kthread+0xe7/0x120
[  606.298908]        ret_from_fork+0x3c/0x60
[  606.298919]        ret_from_fork_asm+0x1a/0x30
[  606.298929]
               -> #1 (&adev->enforce_isolation_mutex){+.+.}-{3:3}:
[  606.298947]        __mutex_lock+0x85/0x930
[  606.298956]        mutex_lock_nested+0x1b/0x30
[  606.298966]        amdgpu_gfx_enforce_isolation_handler+0x87/0x370 [amdgpu]
[  606.299190]        process_one_work+0x21e/0x680
[  606.299199]        worker_thread+0x190/0x350
[  606.299208]        kthread+0xe7/0x120
[  606.299217]        ret_from_fork+0x3c/0x60
[  606.299227]        ret_from_fork_asm+0x1a/0x30
[  606.299236]
               -> #0 ((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work)){+.+.}-{0:0}:
[  606.299257]        __lock_acquire+0x16f9/0x2810
[  606.299267]        lock_acquire+0xd1/0x300
[  606.299276]        __flush_work+0x250/0x610
[  606.299286]        cancel_delayed_work_sync+0x71/0x80
[  606.299296]        amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu]
[  606.299509]        amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.299723]        amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.299909]        amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.300101]        amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.300355]        drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.300369]        process_one_work+0x21e/0x680
[  606.300378]        worker_thread+0x190/0x350
[  606.300387]        kthread+0xe7/0x120
[  606.300396]        ret_from_fork+0x3c/0x60
[  606.300406]        ret_from_fork_asm+0x1a/0x30
[  606.300416]
               other info that might help us debug this:

[  606.300428] Chain exists of:
                 (work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work) --> &adev->enforce_isolation_mutex --> &adev->gfx.kfd_sch_mutex

[  606.300458]  Possible unsafe locking scenario:

[  606.300468]        CPU0                    CPU1
[  606.300476]        ----                    ----
[  606.300484]   lock(&adev->gfx.kfd_sch_mutex);
[  606.300494]                                lock(&adev->enforce_isolation_mutex);
[  606.300508]                                lock(&adev->gfx.kfd_sch_mutex);
[  606.300521]   lock((work_completion)(&(&adev->gfx.enforce_isolation[i].work)->work));
[  606.300536]
                *** DEADLOCK ***

[  606.300546] 5 locks held by kworker/u96:3/3825:
[  606.300555]  #0: ffff9aa5aa1f5d58 ((wq_completion)comp_1.1.0){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[  606.300577]  #1: ffffaa53c3c97e40 ((work_completion)(&sched->work_run_job)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[  606.300600]  #2: ffff9aa64e463c98 (&adev->enforce_isolation_mutex){+.+.}-{3:3}, at: amdgpu_gfx_enforce_isolation_ring_begin_use+0x1c3/0x5d0 [amdgpu]
[  606.300837]  #3: ffff9aa64e432338 (&adev->gfx.kfd_sch_mutex){+.+.}-{3:3}, at: amdgpu_gfx_kfd_sch_ctrl+0x51/0x4d0 [amdgpu]
[  606.301062]  #4: ffffffff8c1a5660 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x70/0x610
[  606.301083]
               stack backtrace:
[  606.301092] CPU: 14 PID: 3825 Comm: kworker/u96:3 Tainted: G           OE      6.10.0-amd-mlkd-610-311224-lof torvalds#19
[  606.301109] Hardware name: Gigabyte Technology Co., Ltd. X570S GAMING X/X570S GAMING X, BIOS F7 03/22/2024
[  606.301124] Workqueue: comp_1.1.0 drm_sched_run_job_work [gpu_sched]
[  606.301140] Call Trace:
[  606.301146]  <TASK>
[  606.301154]  dump_stack_lvl+0x9b/0xf0
[  606.301166]  dump_stack+0x10/0x20
[  606.301175]  print_circular_bug+0x26c/0x340
[  606.301187]  check_noncircular+0x157/0x170
[  606.301197]  ? register_lock_class+0x48/0x490
[  606.301213]  __lock_acquire+0x16f9/0x2810
[  606.301230]  lock_acquire+0xd1/0x300
[  606.301239]  ? __flush_work+0x232/0x610
[  606.301250]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.301261]  ? mark_held_locks+0x54/0x90
[  606.301274]  ? __flush_work+0x232/0x610
[  606.301284]  __flush_work+0x250/0x610
[  606.301293]  ? __flush_work+0x232/0x610
[  606.301305]  ? __pfx_wq_barrier_func+0x10/0x10
[  606.301318]  ? mark_held_locks+0x54/0x90
[  606.301331]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.301345]  cancel_delayed_work_sync+0x71/0x80
[  606.301356]  amdgpu_gfx_kfd_sch_ctrl+0x287/0x4d0 [amdgpu]
[  606.301661]  amdgpu_gfx_enforce_isolation_ring_begin_use+0x2a4/0x5d0 [amdgpu]
[  606.302050]  ? srso_alias_return_thunk+0x5/0xfbef5
[  606.302069]  amdgpu_ring_alloc+0x48/0x70 [amdgpu]
[  606.302452]  amdgpu_ib_schedule+0x176/0x8a0 [amdgpu]
[  606.302862]  ? drm_sched_entity_error+0x82/0x190 [gpu_sched]
[  606.302890]  amdgpu_job_run+0xac/0x1e0 [amdgpu]
[  606.303366]  drm_sched_run_job_work+0x24f/0x430 [gpu_sched]
[  606.303388]  process_one_work+0x21e/0x680
[  606.303409]  worker_thread+0x190/0x350
[  606.303424]  ? __pfx_worker_thread+0x10/0x10
[  606.303437]  kthread+0xe7/0x120
[  606.303449]  ? __pfx_kthread+0x10/0x10
[  606.303463]  ret_from_fork+0x3c/0x60
[  606.303476]  ? __pfx_kthread+0x10/0x10
[  606.303489]  ret_from_fork_asm+0x1a/0x30
[  606.303512]  </TASK>

v2: Refactor lock handling to resolve circular dependency (Alex)

- Introduced a `sched_work` flag to defer the call to
  `amdgpu_gfx_kfd_sch_ctrl` until after releasing
  `enforce_isolation_mutex`.
- This change ensures that `amdgpu_gfx_kfd_sch_ctrl` is called outside
  the critical section, preventing the circular dependency and deadlock.
- The `sched_work` flag is set within the mutex-protected section if
  conditions are met, and the actual function call is made afterward.
- This approach ensures consistent lock acquisition order.

Fixes: afefd6f ("drm/amdgpu: Implement Enforce Isolation Handler for KGD/KFD serialization")
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
Suggested-by: Alex Deucher <[email protected]>
Reviewed-by: Alex Deucher <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
(cherry picked from commit 0b6b2dd)
Cc: [email protected]
GallaisPoutine pushed a commit that referenced this issue Jan 23, 2025
Petr Machata says:

====================
mlxsw: Move Tx header handling to PCI driver

Amit Cohen writes:

Tx header should be added to all packets transmitted from the CPU to
Spectrum ASICs. Historically, handling this header was added as a driver
function, as Tx header is different between Spectrum and Switch-X.

From May 2021, there is no support for SwitchX-2 ASIC, and all the relevant
code was removed.

For now, there is no justification to handle Tx header as part of
spectrum.c, we can handle this as part of PCI, in skb_transmit().

This change will also be useful when XDP support will be added to mlxsw,
as for XDP_TX and XDP_REDIRECT actions, Tx header should be added before
transmitting the packet.

Patch set overview:
Patches #1-#2 add structure to store Tx header info and initialize it
Patch #3 moves definitions of Tx header fields to txheader.h
Patch #4 moves Tx header handling to PCI driver
Patch #5 removes unnecessary attribute
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jan 23, 2025
This fixes the following hard lockup in isolate_lru_folios() during memory
reclaim.  If the LRU mostly contains ineligible folios this may trigger
watchdog.

watchdog: Watchdog detected hard LOCKUP on cpu 173
RIP: 0010:native_queued_spin_lock_slowpath+0x255/0x2a0
Call Trace:
	_raw_spin_lock_irqsave+0x31/0x40
	folio_lruvec_lock_irqsave+0x5f/0x90
	folio_batch_move_lru+0x91/0x150
	lru_add_drain_per_cpu+0x1c/0x40
	process_one_work+0x17d/0x350
	worker_thread+0x27b/0x3a0
	kthread+0xe8/0x120
	ret_from_fork+0x34/0x50
	ret_from_fork_asm+0x1b/0x30

lruvec->lru_lock owner:

PID: 2865     TASK: ffff888139214d40  CPU: 40   COMMAND: "kswapd0"
 #0 [fffffe0000945e60] crash_nmi_callback at ffffffffa567a555
 #1 [fffffe0000945e68] nmi_handle at ffffffffa563b171
 #2 [fffffe0000945eb0] default_do_nmi at ffffffffa6575920
 #3 [fffffe0000945ed0] exc_nmi at ffffffffa6575af4
 #4 [fffffe0000945ef0] end_repeat_nmi at ffffffffa6601dde
    [exception RIP: isolate_lru_folios+403]
    RIP: ffffffffa597df53  RSP: ffffc90006fb7c28  RFLAGS: 00000002
    RAX: 0000000000000001  RBX: ffffc90006fb7c60  RCX: ffffea04a2196f88
    RDX: ffffc90006fb7c60  RSI: ffffc90006fb7c60  RDI: ffffea04a2197048
    RBP: ffff88812cbd3010   R8: ffffea04a2197008   R9: 0000000000000001
    R10: 0000000000000000  R11: 0000000000000001  R12: ffffea04a2197008
    R13: ffffea04a2197048  R14: ffffc90006fb7de8  R15: 0000000003e3e937
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <NMI exception stack>
 #5 [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
 #6 [ffffc90006fb7cf8] shrink_active_list at ffffffffa597f788
 #7 [ffffc90006fb7da8] balance_pgdat at ffffffffa5986db0
 #8 [ffffc90006fb7ec0] kswapd at ffffffffa5987354
 #9 [ffffc90006fb7ef8] kthread at ffffffffa5748238
crash>

Scenario:
User processe are requesting a large amount of memory and keep page active.
Then a module continuously requests memory from ZONE_DMA32 area.
Memory reclaim will be triggered due to ZONE_DMA32 watermark alarm reached.
However pages in the LRU(active_anon) list are mostly from
the ZONE_NORMAL area.

Reproduce:
Terminal 1: Construct to continuously increase pages active(anon).
mkdir /tmp/memory
mount -t tmpfs -o size=1024000M tmpfs /tmp/memory
dd if=/dev/zero of=/tmp/memory/block bs=4M
tail /tmp/memory/block

Terminal 2:
vmstat -a 1
active will increase.
procs ---memory--- ---swap-- ---io---- -system-- ---cpu--- ...
 r  b   swpd   free  inact active   si   so    bi    bo
 1  0   0 1445623076 45898836 83646008    0    0     0
 1  0   0 1445623076 43450228 86094616    0    0     0
 1  0   0 1445623076 41003480 88541364    0    0     0
 1  0   0 1445623076 38557088 90987756    0    0     0
 1  0   0 1445623076 36109688 93435156    0    0     0
 1  0   0 1445619552 33663256 95881632    0    0     0
 1  0   0 1445619804 31217140 98327792    0    0     0
 1  0   0 1445619804 28769988 100774944    0    0     0
 1  0   0 1445619804 26322348 103222584    0    0     0
 1  0   0 1445619804 23875592 105669340    0    0     0

cat /proc/meminfo | head
Active(anon) increase.
MemTotal:       1579941036 kB
MemFree:        1445618500 kB
MemAvailable:   1453013224 kB
Buffers:            6516 kB
Cached:         128653956 kB
SwapCached:            0 kB
Active:         118110812 kB
Inactive:       11436620 kB
Active(anon):   115345744 kB
Inactive(anon):   945292 kB

When the Active(anon) is 115345744 kB, insmod module triggers
the ZONE_DMA32 watermark.

perf record -e vmscan:mm_vmscan_lru_isolate -aR
perf script
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=2
nr_skipped=2 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=29
nr_skipped=29 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon

See nr_scanned=28835844.
28835844 * 4k = 115343376KB approximately equal to 115345744 kB.

If increase Active(anon) to 1000G then insmod module triggers
the ZONE_DMA32 watermark. hard lockup will occur.

In my device nr_scanned = 0000000003e3e937 when hard lockup.
Convert to memory size 0x0000000003e3e937 * 4KB = 261072092 KB.

   [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
    ffffc90006fb7c30: 0000000000000020 0000000000000000
    ffffc90006fb7c40: ffffc90006fb7d40 ffff88812cbd3000
    ffffc90006fb7c50: ffffc90006fb7d30 0000000106fb7de8
    ffffc90006fb7c60: ffffea04a2197008 ffffea0006ed4a48
    ffffc90006fb7c70: 0000000000000000 0000000000000000
    ffffc90006fb7c80: 0000000000000000 0000000000000000
    ffffc90006fb7c90: 0000000000000000 0000000000000000
    ffffc90006fb7ca0: 0000000000000000 0000000003e3e937
    ffffc90006fb7cb0: 0000000000000000 0000000000000000
    ffffc90006fb7cc0: 8d7c0b56b7874b00 ffff88812cbd3000

About the Fixes:
Why did it take eight years to be discovered?

The problem requires the following conditions to occur:
1. The device memory should be large enough.
2. Pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area.
3. The memory in ZONE_DMA32 needs to reach the watermark.

If the memory is not large enough, or if the usage design of ZONE_DMA32
area memory is reasonable, this problem is difficult to detect.

notes:
The problem is most likely to occur in ZONE_DMA32 and ZONE_NORMAL,
but other suitable scenarios may also trigger the problem.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b2e1875 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Signed-off-by: liuye <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jan 23, 2025
Hou Tao says:

====================
The patch set continues the previous work [1] to move all the freeings
of htab elements out of bucket lock. One motivation for the patch set is
the locking problem reported by Sebastian [2]: the freeing of bpf_timer
under PREEMPT_RT may acquire a spin-lock (namely softirq_expiry_lock).
However the freeing procedure for htab element has already held a
raw-spin-lock (namely bucket lock), and it will trigger the warning:
"BUG: scheduling while atomic" as demonstrated by the selftests patch.
Another motivation is to reduce the locked scope of bucket lock.

However, the patch set doesn't move all freeing of htab element out of
bucket lock, it still keep the free of special fields in pre-allocated
hash map under the protect of bucket lock in htab_map_update_elem(). The
patch set is structured as follows:

* Patch #1 moves the element freeing out of bucket lock for
  htab_lru_map_delete_node(). However the freeing is still in the locked
  scope of LRU raw spin lock.
* Patch #2~#3 move the element freeing out of bucket lock for
  __htab_map_lookup_and_delete_elem()
* Patch #4 cancels the bpf_timer in two steps to fix the locking
  problem in htab_map_update_elem() for PREEMPT_PRT.
* Patch #5 adds a selftest for the locking problem

Please see individual patches for more details. Comments are always
welcome.
---

v3:
 * patch #1: update the commit message to state that the freeing of
   special field is still in the locked scope of LRU raw spin lock
 * patch #4: cancel the bpf_timer in two steps only for PREEMPT_RT
   (suggested by Alexei)

v2: https://lore.kernel.org/bpf/[email protected]
  * cancels the bpf timer in two steps instead of breaking the reuse
    the refill of per-cpu ->extra_elems into two steps

v1: https://lore.kernel.org/bpf/[email protected]

[1]: https://lore.kernel.org/bpf/[email protected]
[2]: https://lore.kernel.org/bpf/[email protected]
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jan 27, 2025
When COWing a relocation tree path, at relocation.c:replace_path(), we
can trigger a lockdep splat while we are in the btrfs_search_slot() call
against the relocation root. This happens in that callchain at
ctree.c:read_block_for_search() when we happen to find a child extent
buffer already loaded through the fs tree with a lockdep class set to
the fs tree. So when we attempt to lock that extent buffer through a
relocation tree we have to reset the lockdep class to the class for a
relocation tree, since a relocation tree has extent buffers that used
to belong to a fs tree and may currently be already loaded (we swap
extent buffers between the two trees at the end of replace_path()).

However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset
the lockdep class at ctree.c:read_block_for_search() before we read lock
an extent buffer, just like we did for btrfs_search_slot() in commit
b40130b ("btrfs: fix lockdep splat with reloc root extent buffers").

So add the missing btrfs_maybe_reset_lockdep_class() calls before the
attempts to read lock an extent buffer at ctree.c:read_block_for_search().

The lockdep splat was reported by syzbot and it looks like this:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted
   ------------------------------------------------------
   syz.0.0/5335 is trying to acquire lock:
   ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

   but task is already holding lock:
   ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #2 (btrfs-treloc-02/1){+.+.}-{4:4}:
          reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
          __lock_release kernel/locking/lockdep.c:5563 [inline]
          lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
          up_write+0x79/0x590 kernel/locking/rwsem.c:1629
          btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #1 (btrfs-tree-01/1){+.+.}-{4:4}:
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
          btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
          btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline]
          btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132
          btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351
          btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline]
          btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330
          btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline]
          btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374
          vfs_rename+0xbdb/0xf00 fs/namei.c:5067
          do_renameat2+0xd94/0x13f0 fs/namei.c:5224
          __do_sys_renameat2 fs/namei.c:5258 [inline]
          __se_sys_renameat2 fs/namei.c:5255 [inline]
          __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #0 (btrfs-tree-01){++++}-{4:4}:
          check_prev_add kernel/locking/lockdep.c:3161 [inline]
          check_prevs_add kernel/locking/lockdep.c:3280 [inline]
          validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
          __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
          btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
          btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
          read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
          btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   other info that might help us debug this:

   Chain exists of:
     btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(btrfs-treloc-02/1);
                                  lock(btrfs-tree-01/1);
                                  lock(btrfs-treloc-02/1);
     rlock(btrfs-tree-01);

    *** DEADLOCK ***

   8 locks held by syz.0.0/5335:
    #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
    #1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183
    #2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086
    #3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659
    #4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
    #7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   stack backtrace:
   CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
    check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
    check_prev_add kernel/locking/lockdep.c:3161 [inline]
    check_prevs_add kernel/locking/lockdep.c:3280 [inline]
    validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
    __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
    down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
    btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
    btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
    read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
    btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
    replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
    merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
    merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
    relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1ac6985d29
   Code: ff ff c3 (...)
   RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007
   RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88
    </TASK>

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 9978599 ("btrfs: reduce lock contention when eb cache miss for btree search")
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
GallaisPoutine pushed a commit that referenced this issue Jan 27, 2025
When COWing a relocation tree path, at relocation.c:replace_path(), we
can trigger a lockdep splat while we are in the btrfs_search_slot() call
against the relocation root. This happens in that callchain at
ctree.c:read_block_for_search() when we happen to find a child extent
buffer already loaded through the fs tree with a lockdep class set to
the fs tree. So when we attempt to lock that extent buffer through a
relocation tree we have to reset the lockdep class to the class for a
relocation tree, since a relocation tree has extent buffers that used
to belong to a fs tree and may currently be already loaded (we swap
extent buffers between the two trees at the end of replace_path()).

However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset
the lockdep class at ctree.c:read_block_for_search() before we read lock
an extent buffer, just like we did for btrfs_search_slot() in commit
b40130b ("btrfs: fix lockdep splat with reloc root extent buffers").

So add the missing btrfs_maybe_reset_lockdep_class() calls before the
attempts to read lock an extent buffer at ctree.c:read_block_for_search().

The lockdep splat was reported by syzbot and it looks like this:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted
   ------------------------------------------------------
   syz.0.0/5335 is trying to acquire lock:
   ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

   but task is already holding lock:
   ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #2 (btrfs-treloc-02/1){+.+.}-{4:4}:
          reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
          __lock_release kernel/locking/lockdep.c:5563 [inline]
          lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
          up_write+0x79/0x590 kernel/locking/rwsem.c:1629
          btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #1 (btrfs-tree-01/1){+.+.}-{4:4}:
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
          btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
          btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline]
          btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132
          btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351
          btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline]
          btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330
          btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline]
          btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374
          vfs_rename+0xbdb/0xf00 fs/namei.c:5067
          do_renameat2+0xd94/0x13f0 fs/namei.c:5224
          __do_sys_renameat2 fs/namei.c:5258 [inline]
          __se_sys_renameat2 fs/namei.c:5255 [inline]
          __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #0 (btrfs-tree-01){++++}-{4:4}:
          check_prev_add kernel/locking/lockdep.c:3161 [inline]
          check_prevs_add kernel/locking/lockdep.c:3280 [inline]
          validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
          __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
          btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
          btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
          read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
          btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   other info that might help us debug this:

   Chain exists of:
     btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(btrfs-treloc-02/1);
                                  lock(btrfs-tree-01/1);
                                  lock(btrfs-treloc-02/1);
     rlock(btrfs-tree-01);

    *** DEADLOCK ***

   8 locks held by syz.0.0/5335:
    #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
    #1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183
    #2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086
    #3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659
    #4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
    #7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   stack backtrace:
   CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
    check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
    check_prev_add kernel/locking/lockdep.c:3161 [inline]
    check_prevs_add kernel/locking/lockdep.c:3280 [inline]
    validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
    __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
    down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
    btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
    btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
    read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
    btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
    replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
    merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
    merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
    relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1ac6985d29
   Code: ff ff c3 (...)
   RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007
   RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88
    </TASK>

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: 9978599 ("btrfs: reduce lock contention when eb cache miss for btree search")
Signed-off-by: Filipe Manana <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
avolmat pushed a commit that referenced this issue Feb 9, 2025
libtraceevent parses and returns an array of argument fields, sometimes
larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr",
idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6
elements max, creating an out-of-bounds access. This runtime error is
found by UBsan. The error message:

  $ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1
  builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]'
    #0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966
    #1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110
    #2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436
    #3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897
    #4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335
    #5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502
    #6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351
    #7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404
    #8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448
    #9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556
    #10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360
    torvalds#12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6)

     0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1)                                      = 1

Fixes: 5e58fcf ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint")
Signed-off-by: Howard Chu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
avolmat pushed a commit that referenced this issue Feb 9, 2025
This fixes the following hard lockup in isolate_lru_folios() during memory
reclaim.  If the LRU mostly contains ineligible folios this may trigger
watchdog.

watchdog: Watchdog detected hard LOCKUP on cpu 173
RIP: 0010:native_queued_spin_lock_slowpath+0x255/0x2a0
Call Trace:
	_raw_spin_lock_irqsave+0x31/0x40
	folio_lruvec_lock_irqsave+0x5f/0x90
	folio_batch_move_lru+0x91/0x150
	lru_add_drain_per_cpu+0x1c/0x40
	process_one_work+0x17d/0x350
	worker_thread+0x27b/0x3a0
	kthread+0xe8/0x120
	ret_from_fork+0x34/0x50
	ret_from_fork_asm+0x1b/0x30

lruvec->lru_lock owner:

PID: 2865     TASK: ffff888139214d40  CPU: 40   COMMAND: "kswapd0"
 #0 [fffffe0000945e60] crash_nmi_callback at ffffffffa567a555
 #1 [fffffe0000945e68] nmi_handle at ffffffffa563b171
 #2 [fffffe0000945eb0] default_do_nmi at ffffffffa6575920
 #3 [fffffe0000945ed0] exc_nmi at ffffffffa6575af4
 #4 [fffffe0000945ef0] end_repeat_nmi at ffffffffa6601dde
    [exception RIP: isolate_lru_folios+403]
    RIP: ffffffffa597df53  RSP: ffffc90006fb7c28  RFLAGS: 00000002
    RAX: 0000000000000001  RBX: ffffc90006fb7c60  RCX: ffffea04a2196f88
    RDX: ffffc90006fb7c60  RSI: ffffc90006fb7c60  RDI: ffffea04a2197048
    RBP: ffff88812cbd3010   R8: ffffea04a2197008   R9: 0000000000000001
    R10: 0000000000000000  R11: 0000000000000001  R12: ffffea04a2197008
    R13: ffffea04a2197048  R14: ffffc90006fb7de8  R15: 0000000003e3e937
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <NMI exception stack>
 #5 [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
 #6 [ffffc90006fb7cf8] shrink_active_list at ffffffffa597f788
 #7 [ffffc90006fb7da8] balance_pgdat at ffffffffa5986db0
 #8 [ffffc90006fb7ec0] kswapd at ffffffffa5987354
 #9 [ffffc90006fb7ef8] kthread at ffffffffa5748238
crash>

Scenario:
User processe are requesting a large amount of memory and keep page active.
Then a module continuously requests memory from ZONE_DMA32 area.
Memory reclaim will be triggered due to ZONE_DMA32 watermark alarm reached.
However pages in the LRU(active_anon) list are mostly from
the ZONE_NORMAL area.

Reproduce:
Terminal 1: Construct to continuously increase pages active(anon).
mkdir /tmp/memory
mount -t tmpfs -o size=1024000M tmpfs /tmp/memory
dd if=/dev/zero of=/tmp/memory/block bs=4M
tail /tmp/memory/block

Terminal 2:
vmstat -a 1
active will increase.
procs ---memory--- ---swap-- ---io---- -system-- ---cpu--- ...
 r  b   swpd   free  inact active   si   so    bi    bo
 1  0   0 1445623076 45898836 83646008    0    0     0
 1  0   0 1445623076 43450228 86094616    0    0     0
 1  0   0 1445623076 41003480 88541364    0    0     0
 1  0   0 1445623076 38557088 90987756    0    0     0
 1  0   0 1445623076 36109688 93435156    0    0     0
 1  0   0 1445619552 33663256 95881632    0    0     0
 1  0   0 1445619804 31217140 98327792    0    0     0
 1  0   0 1445619804 28769988 100774944    0    0     0
 1  0   0 1445619804 26322348 103222584    0    0     0
 1  0   0 1445619804 23875592 105669340    0    0     0

cat /proc/meminfo | head
Active(anon) increase.
MemTotal:       1579941036 kB
MemFree:        1445618500 kB
MemAvailable:   1453013224 kB
Buffers:            6516 kB
Cached:         128653956 kB
SwapCached:            0 kB
Active:         118110812 kB
Inactive:       11436620 kB
Active(anon):   115345744 kB
Inactive(anon):   945292 kB

When the Active(anon) is 115345744 kB, insmod module triggers
the ZONE_DMA32 watermark.

perf record -e vmscan:mm_vmscan_lru_isolate -aR
perf script
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=2
nr_skipped=2 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=29
nr_skipped=29 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon

See nr_scanned=28835844.
28835844 * 4k = 115343376KB approximately equal to 115345744 kB.

If increase Active(anon) to 1000G then insmod module triggers
the ZONE_DMA32 watermark. hard lockup will occur.

In my device nr_scanned = 0000000003e3e937 when hard lockup.
Convert to memory size 0x0000000003e3e937 * 4KB = 261072092 KB.

   [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
    ffffc90006fb7c30: 0000000000000020 0000000000000000
    ffffc90006fb7c40: ffffc90006fb7d40 ffff88812cbd3000
    ffffc90006fb7c50: ffffc90006fb7d30 0000000106fb7de8
    ffffc90006fb7c60: ffffea04a2197008 ffffea0006ed4a48
    ffffc90006fb7c70: 0000000000000000 0000000000000000
    ffffc90006fb7c80: 0000000000000000 0000000000000000
    ffffc90006fb7c90: 0000000000000000 0000000000000000
    ffffc90006fb7ca0: 0000000000000000 0000000003e3e937
    ffffc90006fb7cb0: 0000000000000000 0000000000000000
    ffffc90006fb7cc0: 8d7c0b56b7874b00 ffff88812cbd3000

About the Fixes:
Why did it take eight years to be discovered?

The problem requires the following conditions to occur:
1. The device memory should be large enough.
2. Pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area.
3. The memory in ZONE_DMA32 needs to reach the watermark.

If the memory is not large enough, or if the usage design of ZONE_DMA32
area memory is reasonable, this problem is difficult to detect.

notes:
The problem is most likely to occur in ZONE_DMA32 and ZONE_NORMAL,
but other suitable scenarios may also trigger the problem.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b2e1875 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Signed-off-by: liuye <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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