3.16.7-ckt22 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Eric Dumazet <eduma...@google.com> commit 142a2e7ece8d8ac0e818eb2c91f99ca894730e2a upstream. 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 <eduma...@google.com> Reported-by: Dmitry Vyukov <dvyu...@google.com> Tested-by: Dmitry Vyukov <dvyu...@google.com> Signed-off-by: David S. Miller <da...@davemloft.net> Signed-off-by: Luis Henriques <luis.henriq...@canonical.com> --- net/ipv4/tcp_input.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e3d40a303b8f..43404d3f9da8 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5549,6 +5549,7 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
