From: Hidehiro Kawai Subject: [PATCH 2/2] ext4: fix a bug accessing freed memory in ext4_abort Date: Mon, 27 Oct 2008 16:37:09 +0900 Message-ID: <49056FA5.7070202@hitachi.com> References: <19f34abd0810250422t17990222x78fcf0fad2e6f04b@mail.gmail.com> <49056D29.2010700@hitachi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Vegard Nossum , Jan Kara , Stephen Rothwell , Al Viro , linux-ext4@vger.kernel.org, Andrew Morton , "Rafael J. Wysocki" , Ingo Molnar , Pekka Enberg , linux-kernel@vger.kernel.org, sugita , Satoshi OSHIMA To: Theodore Tso , Linus Torvalds Return-path: Received: from mail9.hitachi.co.jp ([133.145.228.44]:35115 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751901AbYJ0Hhd (ORCPT ); Mon, 27 Oct 2008 03:37:33 -0400 In-Reply-To: <49056D29.2010700@hitachi.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Vegard Nossum reported a bug which accesses freed memory. When journal has been aborted, ext4_put_super() calls ext4_abort() after freeing the journal_t object, and then ext4_abort() accesses it. This patch fix it. Signed-off-by: Hidehiro Kawai --- fs/ext4/super.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) Index: linux-2.6.28-rc2/fs/ext4/super.c =================================================================== --- linux-2.6.28-rc2.orig/fs/ext4/super.c +++ linux-2.6.28-rc2/fs/ext4/super.c @@ -333,7 +333,8 @@ void ext4_abort(struct super_block *sb, EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS; sb->s_flags |= MS_RDONLY; EXT4_SB(sb)->s_mount_opt |= EXT4_MOUNT_ABORT; - jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO); + if (EXT4_SB(sb)->s_journal) + jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO); } void ext4_warning(struct super_block *sb, const char *function, @@ -442,14 +443,16 @@ static void ext4_put_super(struct super_ { struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_super_block *es = sbi->s_es; - int i; + int i, err; ext4_mb_release(sb); ext4_ext_release(sb); ext4_xattr_put_super(sb); - if (jbd2_journal_destroy(sbi->s_journal) < 0) - ext4_abort(sb, __func__, "Couldn't clean up the journal"); + err = jbd2_journal_destroy(sbi->s_journal); sbi->s_journal = NULL; + if (err < 0) + ext4_abort(sb, __func__, "Couldn't clean up the journal"); + if (!(sb->s_flags & MS_RDONLY)) { EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER); es->s_state = cpu_to_le16(sbi->s_mount_state);