From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753521Ab0CIP4H (ORCPT ); Tue, 9 Mar 2010 10:56:07 -0500 Received: from mail-bw0-f209.google.com ([209.85.218.209]:51519 "EHLO mail-bw0-f209.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753Ab0CIP4F (ORCPT ); Tue, 9 Mar 2010 10:56:05 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=hddSZlWJFKbsRvNWyaxKA9qEufvK6vAjD5npbigaEZrxt1KyLJ6A+lTa1asp8zDdYf YLGZzeiFHBAx9GEN71DyWQbF8HsgySJzu1wZ4Iy5pS8NAyPK6oTzh4ETXeVqrcKc2eRu ebwTlmrEK1gL1oOnBpOv4fYP9eICv02OnpsH8= Subject: Re: [2.6.34-rc1] CPU stalls when closing TCP sockets. From: Eric Dumazet To: Tetsuo Handa , David Miller Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, Stephen Hemminger In-Reply-To: <201003090654.o296sCnh065487@www262.sakura.ne.jp> References: <201003090319.o293J6WF026448@www262.sakura.ne.jp> <1268116647.2819.64.camel@edumazet-laptop> <201003090654.o296sCnh065487@www262.sakura.ne.jp> Content-Type: text/plain; charset="UTF-8" Date: Tue, 09 Mar 2010 16:55:56 +0100 Message-ID: <1268150156.3113.12.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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);