diff options
| author | Wei Wang <weiwan@google.com> | 2017-05-18 11:22:33 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-09-15 18:30:18 +0100 |
| commit | 32cb2d4a59d0512aa825e7f0352f66063482cc07 (patch) | |
| tree | 6034fef4ad95a50270153c7fc7d55c469e5bd698 | |
| parent | f664b0113d2bb8d4bcdf5d03b72eb4c433ded452 (diff) | |
tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0
commit 499350a5a6e7512d9ed369ed63a4244b6536f4f8 upstream.
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | net/ipv4/tcp.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 926518b382ec..17d425067d27 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2364,6 +2364,10 @@ int tcp_disconnect(struct sock *sk, int flags) tcp_set_ca_state(sk, TCP_CA_Open); tcp_clear_retrans(tp); inet_csk_delack_init(sk); + /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 + * issue in __tcp_select_window() + */ + icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; tcp_init_send_head(sk); memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); __sk_dst_reset(sk); |