44 lines
1.5 KiB
Diff
44 lines
1.5 KiB
Diff
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From d747a7a51b00984127a88113cdbbc26f91e9d815 Mon Sep 17 00:00:00 2001
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From: WANG Cong <xiyou.wangcong@gmail.com>
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Date: Sat, 24 Jun 2017 23:50:30 -0700
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Subject: [PATCH] tcp: reset sk_rx_dst in tcp_disconnect()
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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We have to reset the sk->sk_rx_dst when we disconnect a TCP
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connection, because otherwise when we re-connect it this
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dst reference is simply overridden in tcp_finish_connect().
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This fixes a dst leak which leads to a loopback dev refcnt
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leak. It is a long-standing bug, Kevin reported a very similar
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(if not same) bug before. Thanks to Andrei for providing such
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a reliable reproducer which greatly narrows down the problem.
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Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.")
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Reported-by: Andrei Vagin <avagin@gmail.com>
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Reported-by: Kevin Xu <kaiwen.xu@hulu.com>
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Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
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---
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net/ipv4/tcp.c | 2 ++
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1 file changed, 2 insertions(+)
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diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
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index b5ea036ca781..40aca7803cf2 100644
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--- a/net/ipv4/tcp.c
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+++ b/net/ipv4/tcp.c
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@@ -2330,6 +2330,8 @@ int tcp_disconnect(struct sock *sk, int flags)
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tcp_init_send_head(sk);
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memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
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__sk_dst_reset(sk);
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+ dst_release(sk->sk_rx_dst);
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+ sk->sk_rx_dst = NULL;
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tcp_saved_syn_free(tp);
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/* Clean up fastopen related fields */
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--
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2.11.0
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