57 lines
1.9 KiB
Diff
57 lines
1.9 KiB
Diff
From 34eef919139f6a7558b43576b12b40731f12f7d7 Mon Sep 17 00:00:00 2001
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From: David S. Miller <davem@davemloft.net>
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Date: Fri, 12 Nov 2010 13:35:00 -0800
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Subject: tcp: Don't change unlocked socket state in tcp_v4_err().
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From: David S. Miller <davem@davemloft.net>
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[ Upstream commit 8f49c2703b33519aaaccc63f571b465b9d2b3a2d ]
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Alexey Kuznetsov noticed a regression introduced by
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commit f1ecd5d9e7366609d640ff4040304ea197fbc618
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("Revert Backoff [v3]: Revert RTO on ICMP destination unreachable")
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The RTO and timer modification code added to tcp_v4_err()
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doesn't check sock_owned_by_user(), which if true means we
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don't have exclusive access to the socket and therefore cannot
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modify it's critical state.
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Just skip this new code block if sock_owned_by_user() is true
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and eliminate the now superfluous sock_owned_by_user() code
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block contained within.
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Reported-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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CC: Damian Lukowski <damian@tvk.rwth-aachen.de>
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Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
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Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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---
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net/ipv4/tcp_ipv4.c | 8 +++-----
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1 file changed, 3 insertions(+), 5 deletions(-)
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--- a/net/ipv4/tcp_ipv4.c
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+++ b/net/ipv4/tcp_ipv4.c
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@@ -415,6 +415,9 @@ void tcp_v4_err(struct sk_buff *icmp_skb
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!icsk->icsk_backoff)
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break;
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+ if (sock_owned_by_user(sk))
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+ break;
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+
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icsk->icsk_backoff--;
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inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) <<
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icsk->icsk_backoff;
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@@ -429,11 +432,6 @@ void tcp_v4_err(struct sk_buff *icmp_skb
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if (remaining) {
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inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
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remaining, TCP_RTO_MAX);
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- } else if (sock_owned_by_user(sk)) {
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- /* RTO revert clocked out retransmission,
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- * but socket is locked. Will defer. */
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- inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
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- HZ/20, TCP_RTO_MAX);
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} else {
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/* RTO revert clocked out retransmission.
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* Will retransmit now */
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