Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750923AbWHBO32 (ORCPT ); Wed, 2 Aug 2006 10:29:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751023AbWHBO32 (ORCPT ); Wed, 2 Aug 2006 10:29:28 -0400 Received: from mx1.dg.gov.cn ([61.145.199.108]:18693 "HELO dg.gov.cn") by vger.kernel.org with SMTP id S1750886AbWHBO31 (ORCPT ); Wed, 2 Aug 2006 10:29:27 -0400 Date: Wed, 2 Aug 2006 22:30:46 +0800 From: Kenneth Lee To: Rusty Russell Cc: linux-kernel@vger.kernel.org Subject: [Patch] kernel: bug fixing for kernel/kmod.c Message-ID: <20060802143046.GA5645@kenny> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Signed-off-by: Kenneth Lee User-Agent: Mutt/1.5.12-2006-07-14 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1439 Lines: 38 I think there is a bug in kmod.c: In __call_usermodehelper(), when kernel_thread(wait_for_helper, ...) return success, since wait_for_helper() might call complete() at any time, the sub_info should not be used any more. Normally wait_for_helper() take a long time to finish, you may not get problem for most of the case. But if you remove /sbin/modprobe, it may become easier for you to get a oop in khelper. the following patch is made in 2.6.17.7 --- linux-2.6.17.7/kernel/kmod.c.orig 2006-08-02 22:13:21.805902750 +0800 +++ linux-2.6.17.7/kernel/kmod.c 2006-08-02 22:15:36.946348500 +0800 @@ -198,6 +198,7 @@ static void __call_usermodehelper(void * { struct subprocess_info *sub_info = data; pid_t pid; + int wait = sub_info->wait; /* CLONE_VFORK: wait until the usermode helper has execve'd * successfully We need the data structures to stay around @@ -212,7 +213,7 @@ static void __call_usermodehelper(void * if (pid < 0) { sub_info->retval = pid; complete(sub_info->complete); - } else if (!sub_info->wait) + } else if (!wait) complete(sub_info->complete); } -- - 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/