From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761005AbYENRSD (ORCPT ); Wed, 14 May 2008 13:18:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753376AbYENRRy (ORCPT ); Wed, 14 May 2008 13:17:54 -0400 Received: from po-out-1718.google.com ([72.14.252.159]:57292 "EHLO po-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752750AbYENRRx (ORCPT ); Wed, 14 May 2008 13:17:53 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=fPvj7z7Zzl0QFo18vquwCM58mvhC4i4gyyOTfumcC/SHtwbxBN88lJ/D2+QDeXI6iAYJXANdu35Rgs5SOmghOqWyitm2RuUf8/Ot/f6aikBpLQP1eY6AJe46TaJ6yI6e/+fm0Q7lANP2FC/yHWtcKUHh0404JeUdJQbq16BH2dc= Message-ID: <19f34abd0805141017g26c13e96t2e7edc23bec263d0@mail.gmail.com> Date: Wed, 14 May 2008 19:17:53 +0200 From: "Vegard Nossum" To: "Harald Dunkel" , "Alan Cox" Subject: Re: 2.6.25.3: su gets stuck for root Cc: linux-kernel@vger.kernel.org In-Reply-To: <482B1BD2.8040400@t-online.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <4829326A.6060808@t-online.de> <19f34abd0805122347x4d9c5d03m16679d724189790e@mail.gmail.com> <4829D345.7020909@t-online.de> <19f34abd0805140034j75d97ecbw5a03c200645768cb@mail.gmail.com> <482B1BD2.8040400@t-online.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 14, 2008 at 7:05 PM, Harald Dunkel wrote: > Vegard Nossum wrote: >> >> Ah, tough luck. What if you attach an strace to the already stuck >> process? Like strace -p pid. It's a long shot, but worth a try, I >> suppose. >> > > As suggested I attached strace to the blocking stty. I got a > continuous flow of > > : > : > ioctl(0, SNDCTL_TMR_STOP or TCSETSW, {B38400 opost isig icanon echo ...}) = > ? ERESTARTSYS (To be restarted) > --- SIGTTOU (Stopped (tty output)) @ 0 (0) --- > --- SIGTTOU (Stopped (tty output)) @ 0 (0) --- > : > : > > I also moved back to an old version of coreutils from about > 4 months ago. Same result. Looks good. Adding Alan Cox to conversation. Original report: -------- If I run "su someuser" as root, then it gets stuck. No prompt. I cannot interrupt it with ^C or ^Z either. /var/log/auth.log says: May 13 08:06:41 pluto su[4193]: Successful su for root by harri May 13 08:06:41 pluto su[4193]: + pts/3 harri:root May 13 08:06:41 pluto su[4193]: pam_unix(su:session): session opened for user root by harri(uid=1000) ps shows: % ps -ef | grep pts/3 harri 4007 4006 0 07:58 pts/3 00:00:00 bash root 4193 4007 0 08:06 pts/3 00:00:00 su root 4194 4193 0 08:06 pts/3 00:00:00 bash root 4209 4194 0 08:08 pts/3 00:00:00 su root 4210 4209 0 08:08 pts/3 00:00:00 bash root 4217 4210 0 08:08 pts/3 00:00:00 stty intr ^C So obviously 'stty' is to blame here (called from root's .bashrc, as it seems). But for 2.6.24.4 there is no such problem. -------- Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036