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 18093C28B2C for ; Mon, 8 Aug 2022 01:57:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243709AbiHHB5V (ORCPT ); Sun, 7 Aug 2022 21:57:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244019AbiHHB4s (ORCPT ); Sun, 7 Aug 2022 21:56:48 -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 EF0E2D6E; Sun, 7 Aug 2022 18:40:12 -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 DFF3CB80E05; Mon, 8 Aug 2022 01:40:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD3D6C433D6; Mon, 8 Aug 2022 01:40:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659922809; bh=0cL3Dcoz+m5ju3J7fznTl2vrUU2QaKfVBD5LsLZ8zDc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HlN8AvayQwA+ayxPVeCtpxmqEj6uGVOCpcYXoXpS47pdCHQ97qSFO5rrSeYl1WWp4 wlMYZs11WHGucjzB+k2KKNN1P90JqObjokiseOnCmMyCL/SEq/Azs8z6XaVVJKfkGG /p4Nq0P6t2C20ZEscUYpj/IHMPpN4CtbKPq1BrOhnGVu8X4StPX+Fq5NC0c1VD7kkO fPq9/BihFntYxnC58TiFEJfrEOQ8p9uP+Vi1bReb7mpQaiYhUf0GX1RToZdjhdplvr WKLJZkUfIZxPAN0NPlsSiUgGHWmCaK/xZFMOFYcQRLzDNDWhGb5qCSfqWkR6uglW4D I0Hs6IRP1jrAw== 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 4.9 2/8] ext2: Add more validity checks for inode counts Date: Sun, 7 Aug 2022 21:39:57 -0400 Message-Id: <20220808014005.317064-2-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220808014005.317064-1-sashal@kernel.org> References: <20220808014005.317064-1-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 5ca1f73958b0..7cc83403ebe7 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -1042,9 +1042,10 @@ 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; } @@ -1054,6 +1055,13 @@ 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