From nobody Tue Dec 16 12:16:58 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 B9CFAC28B2B for ; Fri, 19 Aug 2022 16:48:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354076AbiHSQsa (ORCPT ); Fri, 19 Aug 2022 12:48:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354103AbiHSQpu (ORCPT ); Fri, 19 Aug 2022 12:45:50 -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 31E6F12A558; Fri, 19 Aug 2022 09:11:57 -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 6E644B8281C; Fri, 19 Aug 2022 16:11:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE8E4C433C1; Fri, 19 Aug 2022 16:11:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660925516; bh=GMnZ7tRDjtB+T0jWJGzxZ1tR9+AlNiyqah4xgPle83g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ctvcKVJHzUUV9rOzPge1oqrHoFNw8yO5juPBstZtS40fNvRvkS6i+oFXPizqaMAsD s2epNZ2ysJnlk3zlQlaZmAdH9jZmheFiFCcbvs39ubnUcpe8Af7L5hB2RMcg2RHrrU F+5IMUnkveHXWL25vlTpLMuUBlChxO9JAjw4OhXY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukas Czerner , Andreas Dilger , Theodore Tso Subject: [PATCH 5.10 516/545] ext4: check if directory block is within i_size Date: Fri, 19 Aug 2022 17:44:46 +0200 Message-Id: <20220819153852.607421846@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220819153829.135562864@linuxfoundation.org> References: <20220819153829.135562864@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 commit 65f8ea4cd57dbd46ea13b41dc8bac03176b04233 upstream. 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: Greg Kroah-Hartman --- fs/ext4/namei.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -109,6 +109,13 @@ static struct buffer_head *__ext4_read_d 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