Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759919AbZAaCz6 (ORCPT ); Fri, 30 Jan 2009 21:55:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755908AbZAaCrD (ORCPT ); Fri, 30 Jan 2009 21:47:03 -0500 Received: from kroah.org ([198.145.64.141]:54983 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752538AbZAaCq6 (ORCPT ); Fri, 30 Jan 2009 21:46:58 -0500 Date: Fri, 30 Jan 2009 18:40:42 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk Subject: [patch 25/32] ext3: Add sanity check to make_indexed_dir Message-ID: <20090131024042.GZ12147@kroah.com> References: <20090131023411.032399235@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="ext3-add-sanity-check-to-make_indexed_dir.patch" In-Reply-To: <20090131023906.GA12147@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2386 Lines: 73 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Theodore Ts'o commit a21102b55c4f8dfd3adb4a15a34cd62237b46039 upstream. Make sure the rec_len field in the '..' entry is sane, lest we overrun the directory block and cause a kernel oops on a purposefully corrupted filesystem. This fixes a bug related to a bug originally reported by Sami Liedes for ext4 at: http://bugzilla.kernel.org/show_bug.cgi?id=12430 Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext3/namei.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) --- a/fs/ext3/namei.c +++ b/fs/ext3/namei.c @@ -1374,7 +1374,7 @@ static int make_indexed_dir(handle_t *ha struct fake_dirent *fde; blocksize = dir->i_sb->s_blocksize; - dxtrace(printk("Creating index\n")); + dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); retval = ext3_journal_get_write_access(handle, bh); if (retval) { ext3_std_error(dir->i_sb, retval); @@ -1383,6 +1383,19 @@ static int make_indexed_dir(handle_t *ha } root = (struct dx_root *) bh->b_data; + /* The 0th block becomes the root, move the dirents out */ + fde = &root->dotdot; + de = (struct ext3_dir_entry_2 *)((char *)fde + + ext3_rec_len_from_disk(fde->rec_len)); + if ((char *) de >= (((char *) root) + blocksize)) { + ext3_error(dir->i_sb, __func__, + "invalid rec_len for '..' in inode %lu", + dir->i_ino); + brelse(bh); + return -EIO; + } + len = ((char *) root) + blocksize - (char *) de; + bh2 = ext3_append (handle, dir, &block, &retval); if (!(bh2)) { brelse(bh); @@ -1391,11 +1404,6 @@ static int make_indexed_dir(handle_t *ha EXT3_I(dir)->i_flags |= EXT3_INDEX_FL; data1 = bh2->b_data; - /* The 0th block becomes the root, move the dirents out */ - fde = &root->dotdot; - de = (struct ext3_dir_entry_2 *)((char *)fde + - ext3_rec_len_from_disk(fde->rec_len)); - len = ((char *) root) + blocksize - (char *) de; memcpy (data1, de, len); de = (struct ext3_dir_entry_2 *) data1; top = data1 + len; -- 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/