diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-11-15 13:26:28 -0700 |
|---|---|---|
| committer | Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> | 2016-11-15 14:54:51 -0700 |
| commit | 68b87a2b4ab9b0883915656883a5520d4cca3d1a (patch) | |
| tree | ec5810ab65125c23d04ea919f481e48294527601 /net/ipv6/tcp_ipv6.c | |
| parent | f36f22a49d4d32ae12a6557ab1a630f5a74da857 (diff) | |
tcp: take care of truncations done by sk_filter()
With syzkaller help, Marco Grassi found a bug in TCP stack,
crashing in tcp_collapse()
Root cause is that sk_filter() can truncate the incoming skb,
but TCP stack was not really expecting this to happen.
It probably was expecting a simple DROP or ACCEPT behavior.
We first need to make sure no part of TCP header could be removed.
Then we need to adjust TCP_SKB_CB(skb)->end_seq
Many thanks to syzkaller team and Marco for giving us a reproducer.
CRs-Fixed: 1089895
Change-Id: I84185558fa6e80b13d7d0078bda9d75143680941
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Marco Grassi <marco.gra@gmail.com>
Reported-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-commit: ac6e780070e30e4c35bd395acfe9191e6268bdd3
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
[subashab@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 04955a5d2350..8647afa77db4 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1199,7 +1199,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) if (skb->protocol == htons(ETH_P_IP)) return tcp_v4_do_rcv(sk, skb); - if (sk_filter(sk, skb)) + if (tcp_filter(sk, skb)) goto discard; /* @@ -1431,8 +1431,10 @@ process: if (tcp_v6_inbound_md5_hash(sk, skb)) goto discard_and_relse; - if (sk_filter(sk, skb)) + if (tcp_filter(sk, skb)) goto discard_and_relse; + th = (const struct tcphdr *)skb->data; + hdr = ipv6_hdr(skb); skb->dev = NULL; |