From 4158b3431f473aad101da1100a9b241ff8b3cc74 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 12 May 2016 11:17:52 -0700 Subject: [PATCH] xt_qtaguid: Fix panic caused by processing non-full socket. In an issue very similar to 4e461c777e3 (xt_qtaguid: Fix panic caused by synack processing), we were seeing panics on occasion in testing. In this case, it was the same issue, but caused by a different call path, as the sk being returned from qtaguid_find_sk() was not a full socket. Resulting in the sk->sk_socket deref to fail. This patch adds an extra check to ensure the sk being retuned is a full socket, and if not it returns NULL. Reported-by: Milosz Wasilewski Signed-off-by: John Stultz --- net/netfilter/xt_qtaguid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/xt_qtaguid.c b/net/netfilter/xt_qtaguid.c index 822dc3c3bce1..e2e7d54f9bb1 100644 --- a/net/netfilter/xt_qtaguid.c +++ b/net/netfilter/xt_qtaguid.c @@ -1606,7 +1606,7 @@ static struct sock *qtaguid_find_sk(const struct sk_buff *skb, * When in TCP_TIME_WAIT the sk is not a "struct sock" but * "struct inet_timewait_sock" which is missing fields. */ - if (sk->sk_state == TCP_TIME_WAIT) { + if (!sk_fullsock(sk) || sk->sk_state == TCP_TIME_WAIT) { sock_gen_put(sk); sk = NULL; } -- 2.34.1