diff options
| author | Wei Wang <weiwan@google.com> | 2017-05-18 20:22:33 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-05-21 19:24:47 +0200 |
| commit | 499350a5a6e7512d9ed369ed63a4244b6536f4f8 (patch) | |
| tree | 4b81c6f4df9119704c570e73a6cdde12094e1c89 | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf (diff) | |
| download | linux-499350a5a6e7512d9ed369ed63a4244b6536f4f8.tar.xz linux-499350a5a6e7512d9ed369ed63a4244b6536f4f8.zip | |
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>
| -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 1e4c76d2b827..842b575f8fdd 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2320,6 +2320,10 @@ 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); |