From nobody Fri Dec 19 20:51:07 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A211AC32772 for ; Tue, 23 Aug 2022 09:38:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351705AbiHWJiz (ORCPT ); Tue, 23 Aug 2022 05:38:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351594AbiHWJh7 (ORCPT ); Tue, 23 Aug 2022 05:37:59 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1BC295A158; Tue, 23 Aug 2022 01:40:48 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0030FB81C6A; Tue, 23 Aug 2022 08:39:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50021C4314C; Tue, 23 Aug 2022 08:39:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661243992; bh=bKOMXVn5Qf7CFuGv6kc/zrvEaFQfUTDMxbBHWEk4aqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tXwh8GvFoWbkZxeeWct7H1lxFaT+mLpjhbuuRXWSdAJcohumDgORef7/CSQ8ik6WI 2kG6iLpdginPggKKUQw5/s9uBHBKem+dCIbV6ZpVbpGkxQsrIKlOOPYnb9hoUY3dGi ZtQk0425EnmGWUALWA82Nm2uMuUMFOISwcEHjYkc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+d273f7d7f58afd93be48@syzkaller.appspotmail.com, Jan Kara , Sasha Levin Subject: [PATCH 4.14 041/229] ext2: Add more validity checks for inode counts Date: Tue, 23 Aug 2022 10:23:22 +0200 Message-Id: <20220823080055.066458693@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080053.202747790@linuxfoundation.org> References: <20220823080053.202747790@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Jan Kara [ Upstream commit fa78f336937240d1bc598db817d638086060e7e9 ] Add checks verifying number of inodes stored in the superblock matches the number computed from number of inodes per group. Also verify we have at least one block worth of inodes per group. This prevents crashes on corrupted filesystems. Reported-by: syzbot+d273f7d7f58afd93be48@syzkaller.appspotmail.com Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/ext2/super.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/ext2/super.c b/fs/ext2/super.c index f3d55f1c0ce4..5f7079b65426 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -1072,9 +1072,10 @@ static int ext2_fill_super(struct super_block *sb, v= oid *data, int silent) sbi->s_frags_per_group); goto failed_mount; } - if (sbi->s_inodes_per_group > sb->s_blocksize * 8) { + if (sbi->s_inodes_per_group < sbi->s_inodes_per_block || + sbi->s_inodes_per_group > sb->s_blocksize * 8) { ext2_msg(sb, KERN_ERR, - "error: #inodes per group too big: %lu", + "error: invalid #inodes per group: %lu", sbi->s_inodes_per_group); goto failed_mount; } @@ -1084,6 +1085,13 @@ static int ext2_fill_super(struct super_block *sb, v= oid *data, int silent) sbi->s_groups_count =3D ((le32_to_cpu(es->s_blocks_count) - le32_to_cpu(es->s_first_data_block) - 1) / EXT2_BLOCKS_PER_GROUP(sb)) + 1; + if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=3D + le32_to_cpu(es->s_inodes_count)) { + ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu", + le32_to_cpu(es->s_inodes_count), + (u64)sbi->s_groups_count * sbi->s_inodes_per_group); + goto failed_mount; + } db_count =3D (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / EXT2_DESC_PER_BLOCK(sb); sbi->s_group_desc =3D kmalloc (db_count * sizeof (struct buffer_head *), = GFP_KERNEL); --=20 2.35.1