From: "Darrick J. Wong" Subject: [PATCH v2] ext4: ext4_fill_super shouldn't return 0 on corruption Date: Mon, 15 Nov 2010 15:03:46 -0800 Message-ID: <20101115230346.GB18195@tux1.beaverton.ibm.com> References: <20101115214831.GA18195@tux1.beaverton.ibm.com> <4CE1AC38.9040201@redhat.com> Reply-To: djwong@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Theodore Ts'o" , "Patrick J. LoPresti" , linux-kernel , linux-ext4 , Mingming Cao To: Eric Sandeen Return-path: Received: from e8.ny.us.ibm.com ([32.97.182.138]:43804 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752355Ab0KOXDt (ORCPT ); Mon, 15 Nov 2010 18:03:49 -0500 Content-Disposition: inline In-Reply-To: <4CE1AC38.9040201@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: At the start of ext4_fill_super, ret is set to -EINVAL, and any failure path out of that function returns ret. However, the generic_check_addressable clause sets ret = 0 (if it passes), which means that a subsequent failure (e.g. a group checksum error) returns 0 even though the mount should fail. This causes vfs_kern_mount in turn to think that the mount succeeded, leading to an oops. A simple fix is to avoid using ret for the generic_check_addressable check, which was last changed in commit 30ca22c70e3ef0a96ff84de69cd7e8561b416cb2. v2: Return -EFBIG in the error case, per Eric Sandeen's suggestion. Signed-off-by: Darrick J. Wong --- fs/ext4/super.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 40131b7..120c034 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3257,13 +3257,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) * Test whether we have more sectors than will fit in sector_t, * and whether the max offset is addressable by the page cache. */ - ret = generic_check_addressable(sb->s_blocksize_bits, - ext4_blocks_count(es)); - if (ret) { + if (generic_check_addressable(sb->s_blocksize_bits, + ext4_blocks_count(es))) { ext4_msg(sb, KERN_ERR, "filesystem" " too large to mount safely on this system"); if (sizeof(sector_t) < 8) ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled"); + ret = -EFBIG; goto failed_mount; }