From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52704 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726709AbeKLGCn (ORCPT ); Mon, 12 Nov 2018 01:02:43 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jaco Kroon" , "Andreas Dilger" , "Theodore Ts'o" , "Jan Kara" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: Subject: [PATCH 3.16 088/366] ext4: fix fencepost error in check for inode count overflow during resize In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit 4f2f76f751433908364ccff82f437a57d0e6e9b7 upstream. ext4_resize_fs() has an off-by-one bug when checking whether growing of a filesystem will not overflow inode count. As a result it allows a filesystem with 8192 inodes per group to grow to 64TB which overflows inode count to 0 and makes filesystem unusable. Fix it. Fixes: 3f8a6411fbada1fa482276591e037f3b1adcf55b Reported-by: Jaco Kroon Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Reviewed-by: Andreas Dilger Signed-off-by: Ben Hutchings --- fs/ext4/resize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1906,7 +1906,7 @@ retry: return 0; n_group = ext4_get_group_number(sb, n_blocks_count - 1); - if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { + if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { ext4_warning(sb, "resize would cause inodes_count overflow"); return -EINVAL; }