From: WANG Cong <xiyou.wangcong@xxxxxxxxx>
This patch has been added to the stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit d747a7a51b00984127a88113cdbbc26f91e9d815 ]
We have to reset the sk->sk_rx_dst when we disconnect a TCP
connection, because otherwise when we re-connect it this
dst reference is simply overridden in tcp_finish_connect().
This fixes a dst leak which leads to a loopback dev refcnt
leak. It is a long-standing bug, Kevin reported a very similar
(if not same) bug before. Thanks to Andrei for providing such
a reliable reproducer which greatly narrows down the problem.
Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.")
Reported-by: Andrei Vagin <avagin@xxxxxxxxx>
Reported-by: Kevin Xu <kaiwen.xu@xxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
net/ipv4/tcp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1ba4d0964042..a1de8300cfce 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2227,6 +2227,8 @@ int tcp_disconnect(struct sock *sk, int flags)
tcp_init_send_head(sk);
memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
__sk_dst_reset(sk);
+ dst_release(sk->sk_rx_dst);
+ sk->sk_rx_dst = NULL;
WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
--
2.11.0