From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:60566 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932974AbeGAQPZ (ORCPT ); Sun, 1 Jul 2018 12:15:25 -0400 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 4.4 014/105] ext4: fix fencepost error in check for inode count overflow during resize Date: Sun, 1 Jul 2018 18:01:24 +0200 Message-Id: <20180701153150.471523090@linuxfoundation.org> In-Reply-To: <20180701153149.382300170@linuxfoundation.org> References: <20180701153149.382300170@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-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 @@ -1903,7 +1903,7 @@ 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; }