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openvswitch: Prevent kernel-infoleak in ovs_ct_put_key()
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ovs_ct_put_key() is potentially copying uninitialized kernel stack memory
into socket buffers, since the compiler may leave a 3-byte hole at the end
of `struct ovs_key_ct_tuple_ipv4` and `struct ovs_key_ct_tuple_ipv6`. Fix
it by initializing `orig` with memset().

Fixes: 9dd7f89 ("openvswitch: Add original direction conntrack tuple to sw_flow_key.")
Suggested-by: Dan Carpenter <[email protected]>
Signed-off-by: Peilin Ye <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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peilin-ye authored and davem330 committed Aug 3, 2020
1 parent 038ebb1 commit 9aba6c5
Showing 1 changed file with 20 additions and 18 deletions.
38 changes: 20 additions & 18 deletions net/openvswitch/conntrack.c
Original file line number Diff line number Diff line change
Expand Up @@ -276,10 +276,6 @@ void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
ovs_ct_update_key(skb, NULL, key, false, false);
}

#define IN6_ADDR_INITIALIZER(ADDR) \
{ (ADDR).s6_addr32[0], (ADDR).s6_addr32[1], \
(ADDR).s6_addr32[2], (ADDR).s6_addr32[3] }

int ovs_ct_put_key(const struct sw_flow_key *swkey,
const struct sw_flow_key *output, struct sk_buff *skb)
{
Expand All @@ -301,24 +297,30 @@ int ovs_ct_put_key(const struct sw_flow_key *swkey,

if (swkey->ct_orig_proto) {
if (swkey->eth.type == htons(ETH_P_IP)) {
struct ovs_key_ct_tuple_ipv4 orig = {
output->ipv4.ct_orig.src,
output->ipv4.ct_orig.dst,
output->ct.orig_tp.src,
output->ct.orig_tp.dst,
output->ct_orig_proto,
};
struct ovs_key_ct_tuple_ipv4 orig;

memset(&orig, 0, sizeof(orig));
orig.ipv4_src = output->ipv4.ct_orig.src;
orig.ipv4_dst = output->ipv4.ct_orig.dst;
orig.src_port = output->ct.orig_tp.src;
orig.dst_port = output->ct.orig_tp.dst;
orig.ipv4_proto = output->ct_orig_proto;

if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
sizeof(orig), &orig))
return -EMSGSIZE;
} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
struct ovs_key_ct_tuple_ipv6 orig = {
IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.src),
IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.dst),
output->ct.orig_tp.src,
output->ct.orig_tp.dst,
output->ct_orig_proto,
};
struct ovs_key_ct_tuple_ipv6 orig;

memset(&orig, 0, sizeof(orig));
memcpy(orig.ipv6_src, output->ipv6.ct_orig.src.s6_addr32,
sizeof(orig.ipv6_src));
memcpy(orig.ipv6_dst, output->ipv6.ct_orig.dst.s6_addr32,
sizeof(orig.ipv6_dst));
orig.src_port = output->ct.orig_tp.src;
orig.dst_port = output->ct.orig_tp.dst;
orig.ipv6_proto = output->ct_orig_proto;

if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
sizeof(orig), &orig))
return -EMSGSIZE;
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