4.15-stable review patch. If anyone has any objections, please let me know.
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From: Soheil Hassas Yeganeh soheil@google.com
[ Upstream commit a27fd7a8ed3856faaf5a2ff1c8c5f00c0667aaa0 ]
When the connection is reset, there is no point in keeping the packets on the write queue until the connection is closed.
RFC 793 (page 70) and RFC 793-bis (page 64) both suggest purging the write queue upon RST: https://tools.ietf.org/html/draft-ietf-tcpm-rfc793bis-07
Moreover, this is essential for a correct MSG_ZEROCOPY implementation, because userspace cannot call close(fd) before receiving zerocopy signals even when the connection is reset.
Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY") Signed-off-by: Soheil Hassas Yeganeh soheil@google.com Reviewed-by: Eric Dumazet edumazet@google.com Signed-off-by: Yuchung Cheng ycheng@google.com Signed-off-by: Neal Cardwell ncardwell@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/tcp_input.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3988,6 +3988,7 @@ void tcp_reset(struct sock *sk) /* This barrier is coupled with smp_rmb() in tcp_poll() */ smp_wmb();
+ tcp_write_queue_purge(sk); tcp_done(sk);
if (!sock_flag(sk, SOCK_DEAD))