From nobody Mon Sep 29 20:17:18 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 56276C32762 for ; Mon, 15 Aug 2022 22:32:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350769AbiHOWcL (ORCPT ); Mon, 15 Aug 2022 18:32:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350570AbiHOW07 (ORCPT ); Mon, 15 Aug 2022 18:26:59 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0ACA55F9E; Mon, 15 Aug 2022 12:45:23 -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 0367AB80EAB; Mon, 15 Aug 2022 19:45:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4920BC433C1; Mon, 15 Aug 2022 19:45:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660592720; bh=Ll3VrOpxsVmeadqheby9L6HRHAFePhaWMYtkUoqpQtY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Iq9A8kFwBEgJ7ovw9teq8KFFlWW811EeqTyszpJk5WEMf+gtA9WUYq58aX/7+6Y3D z/mu/0o6HaY5W1nyW6XjDjGCI3ShoIoFjWd53B4NWdvbSQ7sQzoVHS1s5wz9lSqTg8 gxg5Tk0GIFF/MLQOMyhbi0ElnPfnuftLEWqbvg2w= 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 5.19 0155/1157] ext2: Add more validity checks for inode counts Date: Mon, 15 Aug 2022 19:51:51 +0200 Message-Id: <20220815180445.881843213@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@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 f6a19f6d9f6d..cdffa2a041af 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -1059,9 +1059,10 @@ 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; } @@ -1071,6 +1072,13 @@ 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_array(db_count, --=20 2.35.1