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

From: Greg Kroah-Hartman
Date: Thu Mar 29 2018 - 14:02:02 EST


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

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

From: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>


[ 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 <soheil@xxxxxxxxxx>
Signed-off-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Yuchung Cheng <ycheng@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
}