From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757299AbYEMGrk (ORCPT ); Tue, 13 May 2008 02:47:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752152AbYEMGrb (ORCPT ); Tue, 13 May 2008 02:47:31 -0400 Received: from wf-out-1314.google.com ([209.85.200.171]:15623 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751957AbYEMGra (ORCPT ); Tue, 13 May 2008 02:47:30 -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=ig6931v3pXJxJk8QRzH9tpHS2Nr0vZwQkPuCzlW6tCkkawdMKe5cPBrgrWgDQASqKV3l3GaMDiA/i8rD9CSMnCGXF1Qbyyh068YnYwh6uSx4UfJDmojS8c3btyRdOSKBu8HM8R+TYtGMaLJKp0yHalXTG6IKbktuEdDukykUDwQ= Message-ID: <19f34abd0805122347x4d9c5d03m16679d724189790e@mail.gmail.com> Date: Tue, 13 May 2008 08:47:29 +0200 From: "Vegard Nossum" To: "Harald Dunkel" Subject: Re: 2.6.25.3: su gets stuck for root Cc: linux-kernel@vger.kernel.org In-Reply-To: <4829326A.6060808@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> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tue, May 13, 2008 at 8:17 AM, Harald Dunkel wrote: > Hi folks, > > I haven't seen it mentioned here (hopefully I wasn't too blind to see): > > 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: ... > 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. > > > Maybe you could spread some light here? Can you try to run "strace su someuser" instead? This should produce some screenfulls of information, but will also pinpoint the location of the hang in userspace if it's an error somewhere in the path of a system call. Strace will output to stderr, so use 2>strace.txt to capture it to a file. If you do this as root, you should not have to enter any passwords, so they won't be logged either. 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