From ce3653a8d3db096aa163fc80239d8ec1305c81fa Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Pouiller?= Date: Tue, 25 Aug 2020 10:58:24 +0200 Subject: [PATCH] staging: wfx: fix potential use before init MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The trace below can appear: [83613.832200] INFO: trying to register non-static key. [83613.837248] the code is fine but needs lockdep annotation. [83613.842808] turning off the locking correctness validator. [83613.848375] CPU: 3 PID: 141 Comm: kworker/3:2H Tainted: G O 5.6.13-silabs15 #2 [83613.857019] Hardware name: BCM2835 [83613.860605] Workqueue: events_highpri bh_work [wfx] [83613.865552] Backtrace: [83613.868041] [] (dump_backtrace) from [] (show_stack+0x20/0x24) [83613.881463] [] (show_stack) from [] (dump_stack+0xe8/0x114) [83613.888882] [] (dump_stack) from [] (register_lock_class+0x748/0x768) [83613.905035] [] (register_lock_class) from [] (__lock_acquire+0x88/0x13dc) [83613.924192] [] (__lock_acquire) from [] (lock_acquire+0xe8/0x274) [83613.942644] [] (lock_acquire) from [] (_raw_spin_lock_irqsave+0x58/0x6c) [83613.961714] [] (_raw_spin_lock_irqsave) from [] (skb_dequeue+0x24/0x78) [83613.974967] [] (skb_dequeue) from [] (wfx_tx_queues_get+0x96c/0x1294 [wfx]) [83613.989728] [] (wfx_tx_queues_get [wfx]) from [] (bh_work+0x454/0x26d8 [wfx]) [83614.009337] [] (bh_work [wfx]) from [] (process_one_work+0x23c/0x7ec) [83614.028141] [] (process_one_work) from [] (worker_thread+0x4c/0x55c) [83614.046861] [] (worker_thread) from [] (kthread+0x138/0x168) [83614.064876] [] (kthread) from [] (ret_from_fork+0x14/0x20) [83614.072200] Exception stack(0xecad3fb0 to 0xecad3ff8) [83614.077323] 3fa0: 00000000 00000000 00000000 00000000 [83614.085620] 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [83614.093914] 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 Indeed, the code of wfx_add_interface() shows that the interface is enabled to early. So, the spinlock associated with some skb_queue may not yet initialized when wfx_tx_queues_get() is called. Signed-off-by: Jérôme Pouiller Link: https://lore.kernel.org/r/20200825085828.399505-8-Jerome.Pouiller@silabs.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/wfx/sta.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/staging/wfx/sta.c b/drivers/staging/wfx/sta.c index 7a4c9f63c4a2c7..a890fe32161cd6 100644 --- a/drivers/staging/wfx/sta.c +++ b/drivers/staging/wfx/sta.c @@ -759,17 +759,6 @@ int wfx_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif) return -EOPNOTSUPP; } - for (i = 0; i < ARRAY_SIZE(wdev->vif); i++) { - if (!wdev->vif[i]) { - wdev->vif[i] = vif; - wvif->id = i; - break; - } - } - if (i == ARRAY_SIZE(wdev->vif)) { - mutex_unlock(&wdev->conf_mutex); - return -EOPNOTSUPP; - } // FIXME: prefer use of container_of() to get vif wvif->vif = vif; wvif->wdev = wdev; @@ -786,12 +775,22 @@ int wfx_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif) init_completion(&wvif->scan_complete); INIT_WORK(&wvif->scan_work, wfx_hw_scan_work); - mutex_unlock(&wdev->conf_mutex); + wfx_tx_queues_init(wvif); + wfx_tx_policy_init(wvif); + + for (i = 0; i < ARRAY_SIZE(wdev->vif); i++) { + if (!wdev->vif[i]) { + wdev->vif[i] = vif; + wvif->id = i; + break; + } + } + WARN(i == ARRAY_SIZE(wdev->vif), "try to instantiate more vif than supported"); hif_set_macaddr(wvif, vif->addr); - wfx_tx_queues_init(wvif); - wfx_tx_policy_init(wvif); + mutex_unlock(&wdev->conf_mutex); + wvif = NULL; while ((wvif = wvif_iterate(wdev, wvif)) != NULL) { // Combo mode does not support Block Acks. We can re-enable them @@ -823,6 +822,7 @@ void wfx_remove_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif) wvif->vif = NULL; mutex_unlock(&wdev->conf_mutex); + wvif = NULL; while ((wvif = wvif_iterate(wdev, wvif)) != NULL) { // Combo mode does not support Block Acks. We can re-enable them