Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751259AbXAKBVD (ORCPT ); Wed, 10 Jan 2007 20:21:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750992AbXAKBVB (ORCPT ); Wed, 10 Jan 2007 20:21:01 -0500 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:51053 "EHLO sous-sol.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965280AbXAKBVB (ORCPT ); Wed, 10 Jan 2007 20:21:01 -0500 Date: Wed, 10 Jan 2007 17:27:21 -0800 From: Chris Wright To: akpm@osdl.org, torvalds@osdl.org Cc: Eric Sandeen , linux-kernel@vger.kernel.org Subject: [PATCH] ext2: skip pages past number of blocks in ext2_find_entry (CVE-2006-6054) Message-ID: <20070111012721.GO10475@sequoia.sous-sol.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1773 Lines: 50 This one looks like it fell through the cracks, it's in 2.6.19.2 but not upstream yet. thanks, -chris -- Subject: [PATCH] ext2: skip pages past number of blocks in ext2_find_entry (CVE-2006-6054) From: Eric Sandeen This one was pointed out on the MOKB site: http://kernelfun.blogspot.com/2006/11/mokb-09-11-2006-linux-26x-ext2checkpage.html If a directory's i_size is corrupted, ext2_find_entry() will keep processing pages until the i_size is reached, even if there are no more blocks associated with the directory inode. This patch puts in some minimal sanity-checking so that we don't keep checking pages (and issuing errors) if we know there can be no more data to read, based on the block count of the directory inode. This is somewhat similar in approach to the ext3 patch I sent earlier this year. Signed-off-by: Eric Sandeen Signed-off-by: Chris Wright --- Not upstream yet fs/ext2/dir.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- linux-2.6.19.1.orig/fs/ext2/dir.c +++ linux-2.6.19.1/fs/ext2/dir.c @@ -368,6 +368,14 @@ struct ext2_dir_entry_2 * ext2_find_entr } if (++n >= npages) n = 0; + /* next page is past the blocks we've got */ + if (unlikely(n > (dir->i_blocks >> (PAGE_CACHE_SHIFT - 9)))) { + ext2_error(dir->i_sb, __FUNCTION__, + "dir %lu size %lld exceeds block count %llu", + dir->i_ino, dir->i_size, + (unsigned long long)dir->i_blocks); + goto out; + } } while (n != start); out: return NULL; - 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/