| Message ID | 20190723100015.5400-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb() | expand |
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 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 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;
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> --- security/smack/smack_lsm.c | 2 ++ 1 file changed, 2 insertions(+)