Patch "tcp: purge write queue upon RST" has been added to the 4.15-stable tree

Patch "tcp: purge write queue upon RST" has been added to the 4.15-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    tcp: purge write queue upon RST

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tcp-purge-write-queue-upon-rst.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Mar  6 19:02:56 PST 2018
From: Soheil Hassas Yeganeh <soheil@google.com>
Date: Tue, 27 Feb 2018 18:32:18 -0500
Subject: tcp: purge write queue upon RST

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))


Patches currently in stable-queue which might be from soheil@google.com are

queue-4.15/tcp-purge-write-queue-upon-rst.patch
queue-4.15/tcp_bbr-better-deal-with-suboptimal-gso.patch