From mboxrd@z Thu Jan 1 00:00:00 1970 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 65285C3F6B0 for ; Mon, 8 Aug 2022 01:57:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243667AbiHHB5S (ORCPT ); Sun, 7 Aug 2022 21:57:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243886AbiHHB4a (ORCPT ); Sun, 7 Aug 2022 21:56:30 -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 3D7621C93F; Sun, 7 Aug 2022 18:39:53 -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 E4D5EB80E05; Mon, 8 Aug 2022 01:39:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01031C433D6; Mon, 8 Aug 2022 01:39:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659922790; bh=bKOMXVn5Qf7CFuGv6kc/zrvEaFQfUTDMxbBHWEk4aqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YtWwVO+MGjjTykDliOV672OCQUkeFTzYBkJewfkMyFd5JZrzcvC7EZlzww5jaadSQ e+pXCBpp6e42PcVeyBq7dkRSyOcL/c83J0Eh17zE2qOYPF7TzjX38YHG6Y7ridBn0h wUtad8qQcLsqKVBI8RkhwVo/mOXhl37bYjZKwbhSTcmwDI1y2eFHr/FXDRRAVezMd6 /kmdyFvib+hswLGIR2xivn28Wpoq+j0gLdyGw1CUcHeO/hH8W4gGTZPZAJIG3yiJRy +U5mJE9c4GGHQA46iwM/deZ6Ih+ToRid5HIpR0rwwNM2Ouv9gwjzOtbek+BlCVZqIX HD1h9m3eHDiHw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jan Kara , syzbot+d273f7d7f58afd93be48@syzkaller.appspotmail.com, Sasha Levin , jack@suse.com, linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 03/12] ext2: Add more validity checks for inode counts Date: Sun, 7 Aug 2022 21:39:33 -0400 Message-Id: <20220808013943.316907-3-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220808013943.316907-1-sashal@kernel.org> References: <20220808013943.316907-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org 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, void *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, void *data, int silent) sbi->s_groups_count = ((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 != + 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 = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) / EXT2_DESC_PER_BLOCK(sb); sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL); -- 2.35.1