To avoid the problem of dereferencing the null pointer in the x25_accept() function, you need to add an additional check that the pointer skb is not equal to NULL. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Mikhail Lobanov <m.lobanov@xxxxxxxxxxxx> --- net/x25/af_x25.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index f7a7c7798c3b..91bc5994cef6 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -896,7 +896,7 @@ static int x25_accept(struct socket *sock, struct socket *newsock, int flags, goto out2; skb = skb_dequeue(&sk->sk_receive_queue); rc = -EINVAL; - if (!skb->sk) + if (!skb || !skb->sk) goto out2; newsk = skb->sk; sock_graft(newsk, newsock); -- 2.43.0