[PATCH 4.15 04/47] tcp: purge write queue upon aborting the connection

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Soheil Hassas Yeganeh <soh...@google.com>


[ Upstream commit e05836ac07c77dd90377f8c8140bce2a44af5fe7 ]

When the connection is aborted, there is no point in
keeping the packets on the write queue until the connection
is closed.

Similar to a27fd7a8ed38 ('tcp: purge write queue upon RST'),
this is essential for a correct MSG_ZEROCOPY implementation,
because userspace cannot call close(fd) before receiving
zerocopy signals even when the connection is aborted.

Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Soheil Hassas Yeganeh <soh...@google.com>
Signed-off-by: Neal Cardwell <ncardw...@google.com>
Reviewed-by: Eric Dumazet <eduma...@google.com>
Signed-off-by: Yuchung Cheng <ych...@google.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 net/ipv4/tcp.c       |    1 +
 net/ipv4/tcp_timer.c |    1 +
 2 files changed, 2 insertions(+)

--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3542,6 +3542,7 @@ int tcp_abort(struct sock *sk, int err)
 
        bh_unlock_sock(sk);
        local_bh_enable();
+       tcp_write_queue_purge(sk);
        release_sock(sk);
        return 0;
 }
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -34,6 +34,7 @@ static void tcp_write_err(struct sock *s
        sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT;
        sk->sk_error_report(sk);
 
+       tcp_write_queue_purge(sk);
        tcp_done(sk);
        __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONTIMEOUT);
 }