From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933587Ab2JAXcP (ORCPT ); Mon, 1 Oct 2012 19:32:15 -0400 Received: from 1wt.eu ([62.212.114.60]:35175 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932653Ab2JAXAb (ORCPT ); Mon, 1 Oct 2012 19:00:31 -0400 Message-Id: <20121001225200.277864732@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 02 Oct 2012 00:53:00 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Theodore Tso" , Greg Kroah-Hartman , Willy Tarreau Subject: [ 063/180] ext4: check for zero length extent In-Reply-To: <6a854f579a99b4fe2efaca1057e8ae22@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Theodore Ts'o commit 31d4f3a2f3c73f279ff96a7135d7202ef6833f12 upstream. Explicitly test for an extent whose length is zero, and flag that as a corrupted extent. This avoids a kernel BUG_ON assertion failure. Tested: Without this patch, the file system image found in tests/f_ext_zero_len/image.gz in the latest e2fsprogs sources causes a kernel panic. With this patch, an ext4 file system error is noted instead, and the file system is marked as being corrupted. https://bugzilla.kernel.org/show_bug.cgi?id=42859 Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- fs/ext4/extents.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 93f7999..b4402c8 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -358,6 +358,8 @@ static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) ext4_fsblk_t block = ext_pblock(ext); int len = ext4_ext_get_actual_len(ext); + if (len == 0) + return 0; return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); } -- 1.7.2.1.45.g54fbc