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 78962CCA487 for ; Wed, 8 Jun 2022 00:58:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1392619AbiFHAxA (ORCPT ); Tue, 7 Jun 2022 20:53:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1382933AbiFGWM7 (ORCPT ); Tue, 7 Jun 2022 18:12:59 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 079D225F430; Tue, 7 Jun 2022 12:19:48 -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 B551F61935; Tue, 7 Jun 2022 19:19:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1801C385A2; Tue, 7 Jun 2022 19:19:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654629588; bh=jk3GPX/z1hEDFjC03/RcNKJq/h0HQGSSLN8X7A3cII8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VwhS8G4u9U/gVou8hYx+Je3g6I6MsFMQU9a+iO8yvSakVr63VaRE61YbUjYqjXptf YWpGJSkZtFSz4REff9Efg5wx54J5Oo7PgEIfkDHE0xtZ56RB7a+kPy3KQd41sJQpy3 vFgoOdW/WAMTHWLrubDyci5KoCjs2R4uN8Y3tMYw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , Theodore Tso Subject: [PATCH 5.18 745/879] ext4: verify dir block before splitting it Date: Tue, 7 Jun 2022 19:04:23 +0200 Message-Id: <20220607165024.481567191@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607165002.659942637@linuxfoundation.org> References: <20220607165002.659942637@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Kara commit 46c116b920ebec58031f0a78c5ea9599b0d2a371 upstream. Before splitting a directory block verify its directory entries are sane so that the splitting code does not access memory it should not. Cc: stable@vger.kernel.org Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20220518093332.13986-1-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/namei.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -277,9 +277,9 @@ static struct dx_frame *dx_probe(struct struct dx_hash_info *hinfo, struct dx_frame *frame); static void dx_release(struct dx_frame *frames); -static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, - unsigned blocksize, struct dx_hash_info *hinfo, - struct dx_map_entry map[]); +static int dx_make_map(struct inode *dir, struct buffer_head *bh, + struct dx_hash_info *hinfo, + struct dx_map_entry *map_tail); static void dx_sort_map(struct dx_map_entry *map, unsigned count); static struct ext4_dir_entry_2 *dx_move_dirents(struct inode *dir, char *from, char *to, struct dx_map_entry *offsets, @@ -1249,15 +1249,23 @@ static inline int search_dirblock(struct * Create map of hash values, offsets, and sizes, stored at end of block. * Returns number of entries mapped. */ -static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de, - unsigned blocksize, struct dx_hash_info *hinfo, +static int dx_make_map(struct inode *dir, struct buffer_head *bh, + struct dx_hash_info *hinfo, struct dx_map_entry *map_tail) { int count = 0; - char *base = (char *) de; + struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data; + unsigned int buflen = bh->b_size; + char *base = bh->b_data; struct dx_hash_info h = *hinfo; - while ((char *) de < base + blocksize) { + if (ext4_has_metadata_csum(dir->i_sb)) + buflen -= sizeof(struct ext4_dir_entry_tail); + + while ((char *) de < base + buflen) { + if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen, + ((char *)de) - base)) + return -EFSCORRUPTED; if (de->name_len && de->inode) { if (ext4_hash_in_dirent(dir)) h.hash = EXT4_DIRENT_HASH(de); @@ -1270,8 +1278,7 @@ static int dx_make_map(struct inode *dir count++; cond_resched(); } - /* XXX: do we need to check rec_len == 0 case? -Chris */ - de = ext4_next_entry(de, blocksize); + de = ext4_next_entry(de, dir->i_sb->s_blocksize); } return count; } @@ -1943,8 +1950,11 @@ static struct ext4_dir_entry_2 *do_split /* create map in the end of data2 block */ map = (struct dx_map_entry *) (data2 + blocksize); - count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1, - blocksize, hinfo, map); + count = dx_make_map(dir, *bh, hinfo, map); + if (count < 0) { + err = count; + goto journal_error; + } map -= count; dx_sort_map(map, count); /* Ensure that neither split block is over half full */