tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0
authorWei Wang <weiwan@google.com>
Thu, 18 May 2017 18:22:33 +0000 (11:22 -0700)
committerDavid S. Miller <davem@davemloft.net>
Sun, 21 May 2017 17:24:47 +0000 (13:24 -0400)
commit499350a5a6e7512d9ed369ed63a4244b6536f4f8
tree4b81c6f4df9119704c570e73a6cdde12094e1c89
parent23416e230416a9201561f1db553b1515e9959f6a
tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0

When tcp_disconnect() is called, inet_csk_delack_init() sets
icsk->icsk_ack.rcv_mss to 0.
This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() =>
__tcp_select_window() call path to have division by 0 issue.
So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/tcp.c