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| author | Eric Dumazet <edumazet@google.com> | 2015-11-26 08:18:14 -0800 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-12-14 12:19:25 -0500 |
| commit | 7d76c6f791676f1a27fcfad0031209e70509e226 (patch) | |
| tree | e7f4aaca6703339c70b0a59a7b3f121370264710 /net/ipv4/tcp_input.c | |
| parent | ea5ef9fc2c94fd0156d4671f2327d14f830ec80b (diff) | |
| download | linux-stable-7d76c6f791676f1a27fcfad0031209e70509e226.tar.gz linux-stable-7d76c6f791676f1a27fcfad0031209e70509e226.tar.bz2 linux-stable-7d76c6f791676f1a27fcfad0031209e70509e226.zip | |
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: Sasha Levin <sasha.levin@oracle.com>
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 aa167155b686..0c96055b2382 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5540,6 +5540,7 @@ 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 |