diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-11-26 19:18:14 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-12-30 05:26:01 +0300 |
| commit | 6cfa9781d3bf950eed455369966bbdf9d05871c5 (patch) | |
| tree | 479d32e928c479efe2eee16c2af64aa36e458f83 /net/ipv4/tcp_input.c | |
| parent | ca194f27b9dcd0d389b83f27c3a5c84caacb6246 (diff) | |
| download | linux-6cfa9781d3bf950eed455369966bbdf9d05871c5.tar.xz | |
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.
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>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -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 f8b58997c38e..3877e1678247 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5811,6 +5811,7 @@ discard: } 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 |