diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-11-26 08:18:14 -0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-11 11:00:00 +0200 |
| commit | 577404f083773b50679cd5190e7b5bf635f78104 (patch) | |
| tree | f5c46b8357b6ec0bd90b05e0fd0e09e540f24af4 | |
| parent | ecfa6192df533962bccd109759cd4479a6cb3cc7 (diff) | |
tcp: initialize tp->copied_seq in case of cross SYN connection
[ Upstream commit 142a2e7ece8d8ac0e818eb2c91f99ca894730e2a ]
Dmitry provided a syzkaller (http://github.com/google/syzkaller)
generated program that triggers the WARNING at
net/ipv4/tcp.c:1729 in tcp_recvmsg() :
WARN_ON(tp->copied_seq != tp->rcv_nxt &&
!(flags & (MSG_PEEK | MSG_TRUNC)));
His program is specifically attempting a Cross SYN TCP exchange,
that we support (for the pleasure of hackers ?), but it looks we
lack proper tcp->copied_seq initialization.
Thanks again Dmitry for your report and testings.
Change-Id: If950abf82188c20925eecfa8b9bceee90ccc2e78
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | net/ipv4/tcp_input.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 3db9f9616..0d093aacc 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5519,6 +5519,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, * move to established. */ tp->rcv_nxt = TCP_SKB_CB(skb)->seq + 1; + tp->copied_seq = tp->rcv_nxt; tp->rcv_wup = TCP_SKB_CB(skb)->seq + 1; /* RFC1323: The window in SYN & SYN/ACK segments is |