diff options
| author | Wei Wang <weiwan@google.com> | 2017-05-18 11:22:33 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-27 11:00:11 +0200 |
| commit | 611a98c8eca3098173309642df187056c17e0f65 (patch) | |
| tree | f21abc168697a33df4d8f6ba417f5b54784cfa63 /net | |
| parent | 081be8c9efd6003e1aa78679b3265732de4cec9b (diff) | |
tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0
[ Upstream commit 499350a5a6e7512d9ed369ed63a4244b6536f4f8 ]
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -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 0870a86e9d96..5597120c8ffd 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2260,6 +2260,10 @@ 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); |