From: Hidehiro Kawai Subject: [PATCH 1/2] ext3: fix a bug accessing freed memory in ext3_abort Date: Mon, 27 Oct 2008 16:26:33 +0900 Message-ID: <49056D29.2010700@hitachi.com> References: <19f34abd0810250422t17990222x78fcf0fad2e6f04b@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Theodore Tso , Jan Kara , Stephen Rothwell , Al Viro , linux-ext4@vger.kernel.org, Andrew Morton , Linus Torvalds , "Rafael J. Wysocki" , Ingo Molnar , Pekka Enberg , linux-kernel@vger.kernel.org To: Vegard Nossum Return-path: Received: from mail9.hitachi.co.jp ([133.145.228.44]:32827 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751591AbYJ0H0s (ORCPT ); Mon, 27 Oct 2008 03:26:48 -0400 In-Reply-To: <19f34abd0810250422t17990222x78fcf0fad2e6f04b@mail.gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi Vegard, Vegard Nossum wrote: > commit 2d7c820e56ce83b23daee9eb5343730fb309418e > Author: Hidehiro Kawai > Date: Wed Oct 22 14:15:01 2008 -0700 > > ext3: add checks for errors from jbd > > introduces a regression which was discovered by kmemcheck: Thank you for reporting this regression. It's my fault. I send patches to fix. Regards, Subject: [PATCH 1/2] ext3: fix a bug accessing freed memory in ext3_abort Vegard Nossum reported a bug which accesses freed memory. When journal has been aborted, ext3_put_super() calls ext3_abort() after freeing the journal_t object, and then ext3_abort() accesses it. This patch fix it. Signed-off-by: Hidehiro Kawai --- fs/ext3/super.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) Index: linux-2.6.28-rc2/fs/ext3/super.c =================================================================== --- linux-2.6.28-rc2.orig/fs/ext3/super.c +++ linux-2.6.28-rc2/fs/ext3/super.c @@ -281,7 +281,8 @@ void ext3_abort (struct super_block * sb EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS; sb->s_flags |= MS_RDONLY; EXT3_SB(sb)->s_mount_opt |= EXT3_MOUNT_ABORT; - journal_abort(EXT3_SB(sb)->s_journal, -EIO); + if (EXT3_SB(sb)->s_journal) + journal_abort(EXT3_SB(sb)->s_journal, -EIO); } void ext3_warning (struct super_block * sb, const char * function, @@ -390,11 +391,14 @@ static void ext3_put_super (struct super { struct ext3_sb_info *sbi = EXT3_SB(sb); struct ext3_super_block *es = sbi->s_es; - int i; + int i, err; ext3_xattr_put_super(sb); - if (journal_destroy(sbi->s_journal) < 0) + err = journal_destroy(sbi->s_journal); + sbi->s_journal = NULL; + if (err < 0) ext3_abort(sb, __func__, "Couldn't clean up the journal"); + if (!(sb->s_flags & MS_RDONLY)) { EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER); es->s_state = cpu_to_le16(sbi->s_mount_state);