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authorDavid S. Miller <davem@davemloft.net>2010-11-12 16:35:00 -0500
committerDavid S. Miller <davem@davemloft.net>2010-11-12 16:35:00 -0500
commit8f49c2703b33519aaaccc63f571b465b9d2b3a2d (patch)
tree3b2db10ae8642c87c7258522e06ee56910d5b420
parent5ef41308f94dcbb3b7afc56cdef1c2ba53fa5d2f (diff)
tcp: Don't change unlocked socket state in tcp_v4_err().
Alexey Kuznetsov noticed a regression introduced by commit f1ecd5d9e7366609d640ff4040304ea197fbc618 ("Revert Backoff [v3]: Revert RTO on ICMP destination unreachable") The RTO and timer modification code added to tcp_v4_err() doesn't check sock_owned_by_user(), which if true means we don't have exclusive access to the socket and therefore cannot modify it's critical state. Just skip this new code block if sock_owned_by_user() is true and eliminate the now superfluous sock_owned_by_user() code block contained within. Reported-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net> CC: Damian Lukowski <damian@tvk.rwth-aachen.de> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
-rw-r--r--net/ipv4/tcp_ipv4.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 8f8527d41682..69ccbc1dde9c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -415,6 +415,9 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
415 !icsk->icsk_backoff) 415 !icsk->icsk_backoff)
416 break; 416 break;
417 417
418 if (sock_owned_by_user(sk))
419 break;
420
418 icsk->icsk_backoff--; 421 icsk->icsk_backoff--;
419 inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) << 422 inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) <<
420 icsk->icsk_backoff; 423 icsk->icsk_backoff;
@@ -429,11 +432,6 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
429 if (remaining) { 432 if (remaining) {
430 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, 433 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
431 remaining, TCP_RTO_MAX); 434 remaining, TCP_RTO_MAX);
432 } else if (sock_owned_by_user(sk)) {
433 /* RTO revert clocked out retransmission,
434 * but socket is locked. Will defer. */
435 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
436 HZ/20, TCP_RTO_MAX);
437 } else { 435 } else {
438 /* RTO revert clocked out retransmission. 436 /* RTO revert clocked out retransmission.
439 * Will retransmit now */ 437 * Will retransmit now */