From patchwork Thu May 24 11:36:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 919797 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.cz Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40s6mc4qRtz9s2L for ; Thu, 24 May 2018 21:37:04 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S969104AbeEXLhC (ORCPT ); Thu, 24 May 2018 07:37:02 -0400 Received: from mx2.suse.de ([195.135.220.15]:39907 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S969064AbeEXLg7 (ORCPT ); Thu, 24 May 2018 07:36:59 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D5481AC9F; Thu, 24 May 2018 11:36:57 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id B865A1E050C; Thu, 24 May 2018 13:36:56 +0200 (CEST) From: Jan Kara To: Ted Tso Cc: , Jaco Kroon , Jan Kara , stable@vger.kernel.org Subject: [PATCH] ext4: Forbid overflowing inode count when resizing Date: Thu, 24 May 2018 13:36:46 +0200 Message-Id: <20180524113646.3859-1-jack@suse.cz> X-Mailer: git-send-email 2.13.6 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org 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 Acked-By: Jaco Kroon Reviewed-by: Andreas Dilger --- fs/ext4/resize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index b6bec270a8e4..d792b7689d92 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1933,7 +1933,7 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) 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; }