Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755570AbXJCNei (ORCPT ); Wed, 3 Oct 2007 09:34:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753361AbXJCNeb (ORCPT ); Wed, 3 Oct 2007 09:34:31 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:55586 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753028AbXJCNeb (ORCPT ); Wed, 3 Oct 2007 09:34:31 -0400 Date: Wed, 3 Oct 2007 14:34:22 +0100 From: Al Viro To: Ingo Molnar Cc: Linus Torvalds , Linux Kernel Mailing List , Greg KH , Peter Zijlstra Subject: Re: [bug] crash when reading /proc/mounts (was: Re: Linux 2.6.23-rc9 and a heads-up for the 2.6.24 series..) Message-ID: <20071003133422.GI8181@ftp.linux.org.uk> References: <20071003084607.GC32218@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071003084607.GC32218@elte.hu> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1402 Lines: 30 On Wed, Oct 03, 2007 at 10:46:07AM +0200, Ingo Molnar wrote: > > hm, i just triggered the procfs crash below with -rc9 on a testbox. > Config attached. It's easy to reproduce it via 'service sshd restart'. > The crash site is: > > (gdb) list *0xc017599d > 0xc017599d is in seq_path (fs/seq_file.c:354). > 349 if (m->count < m->size) { > 350 char *s = m->buf + m->count; > 351 char *p = d_path(dentry, mnt, s, m->size - m->count); > 352 if (!IS_ERR(p)) { > 353 while (s <= p) { > 354 char c = *p++; > 355 if (!c) { > 356 p = m->buf + m->count; > 357 m->count = s - m->buf; > 358 return s - p; > (gdb) > > any ideas? Fortunately i was able to do an strace of the incident: Charming... So we get d_path() either returning junk or we get something that isn't NUL-terminated. Which one it is? I.e. what does p look like and what's in s? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/