From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Soheil Hassas Yeganeh , Eric Dumazet , Yuchung Cheng , Neal Cardwell , "David S. Miller" Subject: [PATCH 4.14 071/110] tcp: purge write queue upon RST Date: Wed, 7 Mar 2018 11:38:54 -0800 Message-Id: <20180307191048.728849569@linuxfoundation.org> In-Reply-To: <20180307191039.748351103@linuxfoundation.org> References: <20180307191039.748351103@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Soheil Hassas Yeganeh [ 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 Reviewed-by: Eric Dumazet Signed-off-by: Yuchung Cheng Signed-off-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_input.c | 1 + 1 file changed, 1 insertion(+) --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4011,6 +4011,7 @@ 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))