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authorJia-Ju Bai <baijiaju1990@gmail.com>2019-07-23 18:00:15 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-07 19:01:38 +0200
commit397a607551d485877f2218fcd8e077d0a6c2e1eb (patch)
treecbbdd96271a820f14d17b537747f15a78da9596e
parenta4e61e26aa9dd9e4eba43c21c0b862d3ec786b65 (diff)
security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb()
[ Upstream commit 3f4287e7d98a2954f20bf96c567fdffcd2b63eb9 ] In smack_socket_sock_rcv_skb(), there is an if statement on line 3920 to check whether skb is NULL: if (skb && skb->secmark != 0) This check indicates skb can be NULL in some cases. But on lines 3931 and 3932, skb is used: ad.a.u.net->netif = skb->skb_iif; ipv6_skb_to_auditdata(skb, &ad.a, NULL); Thus, possible null-pointer dereferences may occur when skb is NULL. To fix these possible bugs, an if statement is added to check skb. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--security/smack/smack_lsm.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 4c5e5a438f8b..5c9fc8ba6e57 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3925,6 +3925,8 @@ access_check:
skp = smack_ipv6host_label(&sadd);
if (skp == NULL)
skp = smack_net_ambient;
+ if (skb == NULL)
+ break;
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = family;