Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759238Ab0G3R16 (ORCPT ); Fri, 30 Jul 2010 13:27:58 -0400 Received: from kroah.org ([198.145.64.141]:52084 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758353Ab0G3RTx (ORCPT ); Fri, 30 Jul 2010 13:19:53 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Jul 30 10:15:11 2010 Message-Id: <20100730171511.136417144@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 30 Jul 2010 10:15:55 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, "Theodore Tso" Subject: [127/165] ext4: Avoid crashing on NULL ptr dereference on a filesystem error In-Reply-To: <20100730171550.GA1299@kroah.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1895 Lines: 57 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ commit f70f362b4a6fe47c239dbfb3efc0cc2c10e4f09c upstream (as of v2.6.34-git13) If the EOFBLOCK_FL flag is set when it should not be and the inode is zero length, then eh_entries is zero, and ex is NULL, so dereferencing ex to print ex->ee_block causes a kernel OOPS in ext4_ext_map_blocks(). On top of that, the error message which is printed isn't very helpful. So we fix this by printing something more explanatory which doesn't involve trying to print ex->ee_block. Addresses-Google-Bug: #2655740 Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/extents.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3281,8 +3281,8 @@ int ext4_ext_get_blocks(handle_t *handle */ if (path[depth].p_ext == NULL && depth != 0) { ext4_error(inode->i_sb, __func__, "bad extent address " - "inode: %lu, iblock: %d, depth: %d", - inode->i_ino, iblock, depth); + "inode: %lu, iblock: %lu, depth: %d", + inode->i_ino, (unsigned long) iblock, depth); err = -EIO; goto out2; } @@ -3418,8 +3418,11 @@ int ext4_ext_get_blocks(handle_t *handle } else { WARN_ON(eh->eh_entries == 0); ext4_error(inode->i_sb, __func__, - "inode#%lu, eh->eh_entries = 0!", inode->i_ino); - } + "inode#%lu, eh->eh_entries = 0 and " + "EOFBLOCKS_FL set", inode->i_ino); + err = -EIO; + goto out2; + } } err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); if (err) { -- 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/