From nobody Wed Dec 17 09:16:06 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 C1755C32772 for ; Tue, 23 Aug 2022 10:37:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354363AbiHWKhP (ORCPT ); Tue, 23 Aug 2022 06:37:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42616 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354899AbiHWKWX (ORCPT ); Tue, 23 Aug 2022 06:22:23 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 106C513F2D; Tue, 23 Aug 2022 02:03:38 -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 CB69CB81C53; Tue, 23 Aug 2022 09:03:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F10EC433C1; Tue, 23 Aug 2022 09:03:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661245415; bh=2VWKfxtQ5ExyRo+X1gZyywgtIu3OQS7nZSsQWwD9TLw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ho3Wk9ndJF+OqHrntSJxRqe3+dbxODMK+Py8dzndkQJQVTKBkTnx7p0ZaB2T+fk7i kwk1cwBJxqnBT42SIyNgnmEr/7iRiIwFfGZTCHAol89P3jAACmIuUCPM/uvot3yrY8 IZxZBZeXE95PBoc01tSF52XfvcvxlMI48rE3941A= 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 4.19 041/287] ext2: Add more validity checks for inode counts Date: Tue, 23 Aug 2022 10:23:30 +0200 Message-Id: <20220823080101.649109026@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080100.268827165@linuxfoundation.org> References: <20220823080100.268827165@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 ad9fd08f66ba..44a1f356aca2 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -1088,9 +1088,10 @@ 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; } @@ -1100,6 +1101,13 @@ 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