From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jaco Kroon , Jan Kara , Theodore Tso , Andreas Dilger Subject: [PATCH 4.14 18/52] ext4: fix fencepost error in check for inode count overflow during resize Date: Sun, 24 Jun 2018 23:21:11 +0800 Message-Id: <20180624142745.555268342@linuxfoundation.org> In-Reply-To: <20180624142744.234164867@linuxfoundation.org> References: <20180624142744.234164867@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable 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. Cc: stable@vger.kernel.org Fixes: 3f8a6411fbada1fa482276591e037f3b1adcf55b Reported-by: Jaco Kroon Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Reviewed-by: Andreas Dilger Signed-off-by: Greg Kroah-Hartman --- fs/ext4/resize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1905,7 +1905,7 @@ 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; }