From nobody Mon Sep 29 21:09:36 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 C0CCFC25B0D for ; Tue, 16 Aug 2022 04:58:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233814AbiHPE6M (ORCPT ); Tue, 16 Aug 2022 00:58:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233767AbiHPE47 (ORCPT ); Tue, 16 Aug 2022 00:56:59 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E085BC833; Mon, 15 Aug 2022 13:51:39 -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 dfw.source.kernel.org (Postfix) with ESMTPS id A2EC361239; Mon, 15 Aug 2022 20:51:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C6D5C433C1; Mon, 15 Aug 2022 20:51:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660596685; bh=9V2Lh427dE0c3DVs2bzvA7D9zotqaw/O2V5rkXiOl68=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jHJOQ2MeJijf5Ly76fDeuo9j9EilorVZCxkDbpy7Lf5aGMCHz1WKEaG8wM5JFA5v0 XV3UvNQdoOGpnoosEYvDmF/JVaXKuSfdLNldg8nSB4h6VJ82cKxqd9tNaryz95lTN0 pTaQkGuGySeLwyso72xXSP9/bDri6bBIGKmLhdpI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukas Czerner , Andreas Dilger , Theodore Tso , Sasha Levin Subject: [PATCH 5.19 1125/1157] ext4: check if directory block is within i_size Date: Mon, 15 Aug 2022 20:08:01 +0200 Message-Id: <20220815180525.350164423@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: Lukas Czerner [ Upstream commit 65f8ea4cd57dbd46ea13b41dc8bac03176b04233 ] Currently ext4 directory handling code implicitly assumes that the directory blocks are always within the i_size. In fact ext4_append() will attempt to allocate next directory block based solely on i_size and the i_size is then appropriately increased after a successful allocation. However, for this to work it requires i_size to be correct. If, for any reason, the directory inode i_size is corrupted in a way that the directory tree refers to a valid directory block past i_size, we could end up corrupting parts of the directory tree structure by overwriting already used directory blocks when modifying the directory. Fix it by catching the corruption early in __ext4_read_dirblock(). Addresses Red-Hat-Bugzilla: #2070205 CVE: CVE-2022-1184 Signed-off-by: Lukas Czerner Cc: stable@vger.kernel.org Reviewed-by: Andreas Dilger Link: https://lore.kernel.org/r/20220704142721.157985-1-lczerner@redhat.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/namei.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index db4ba99d1ceb..cf460aa4f81d 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -110,6 +110,13 @@ static struct buffer_head *__ext4_read_dirblock(struct= inode *inode, struct ext4_dir_entry *dirent; int is_dx_block =3D 0; =20 + if (block >=3D inode->i_size) { + ext4_error_inode(inode, func, line, block, + "Attempting to read directory block (%u) that is past i_size (%ll= u)", + block, inode->i_size); + return ERR_PTR(-EFSCORRUPTED); + } + if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO)) bh =3D ERR_PTR(-EIO); else --=20 2.35.1