From patchwork Tue Mar 9 15:55:56 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [2.6.34-rc1] CPU stalls when closing TCP sockets. Date: Tue, 09 Mar 2010 05:55:56 -0000 From: Eric Dumazet X-Patchwork-Id: 47166 Message-Id: <1268150156.3113.12.camel@edumazet-laptop> To: Tetsuo Handa , David Miller Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, Stephen Hemminger Le mardi 09 mars 2010 à 15:54 +0900, Tetsuo Handa a écrit : > Eric Dumazet wrote: > > Nothing comes to my mind, I'll try to reproduce this here. > > When stopped at (8), Ctrl-C doesn't work. > > > Is 2.6.33 OK ? > > Yes. 2.6.33 and earlier are OK. OK thanks ! I believe commit d218d11133d888f9745802146a50255a4781d37a (tcp: Generalized TTL Security Mechanism) might be the bug origin. I am testing following patch, based on latest net-2.6 tree (including the LINUX_MIB_TCPMINTTLDROP bit) [PATCH] tcp: Fix tcp_v4_rcv() Commit d218d111 (tcp: Generalized TTL Security Mechanism) added a bug for TIMEWAIT sockets. We should not test min_ttl for TW sockets. Reported-by: Tetsuo Handa Signed-off-by: Eric Dumazet Acked-by: Stephen Hemminger --- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 8d51d39..70df409 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1651,15 +1651,15 @@ int tcp_v4_rcv(struct sk_buff *skb) if (!sk) goto no_tcp_socket; +process: + if (sk->sk_state == TCP_TIME_WAIT) + goto do_time_wait; + if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); goto discard_and_relse; } -process: - if (sk->sk_state == TCP_TIME_WAIT) - goto do_time_wait; - if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) goto discard_and_relse; nf_reset(skb);