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 8630AC67871 for ; Mon, 16 Jan 2023 16:44:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233735AbjAPQoX (ORCPT ); Mon, 16 Jan 2023 11:44:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233822AbjAPQnp (ORCPT ); Mon, 16 Jan 2023 11:43:45 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBB0539BA8 for ; Mon, 16 Jan 2023 08:31:26 -0800 (PST) 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 786546106E for ; Mon, 16 Jan 2023 16:31:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BFB9C433EF; Mon, 16 Jan 2023 16:31:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673886685; bh=xOvi7aIxPjKXJsKEx5kQQgW2dp3oENq6smwAh6Mly+Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2DTvesiQVzY/bJdyYAyPpSOAov5icjWjtZ2d1a+CDrdK9bUqto3Z+gnkOoBuCgx90 3Fw2PmwUyYcaDRLMHmOcYt38LOKlLHlGVCI8Uo7WIObIKGHQ8rh700EGZdUI5aZ1Je hA80eVW6LGZIJ+bjlkGAoCiBa/E0zbwHgP/Fxf5w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Baokun Li , Jason Yan , Jan Kara , Theodore Tso , stable@kernel.org Subject: [PATCH 5.4 524/658] ext4: add EXT4_IGET_BAD flag to prevent unexpected bad inode Date: Mon, 16 Jan 2023 16:50:12 +0100 Message-Id: <20230116154933.511427664@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154909.645460653@linuxfoundation.org> References: <20230116154909.645460653@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Baokun Li commit 63b1e9bccb71fe7d7e3ddc9877dbdc85e5d2d023 upstream. There are many places that will get unhappy (and crash) when ext4_iget() returns a bad inode. However, if iget the boot loader inode, allows a bad inode to be returned, because the inode may not be initialized. This mechanism can be used to bypass some checks and cause panic. To solve this problem, we add a special iget flag EXT4_IGET_BAD. Only with this flag we'd be returning bad inode from ext4_iget(), otherwise we always return the error code if the inode is bad inode.(suggested by Jan Kara) Signed-off-by: Baokun Li Reviewed-by: Jason Yan Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20221026042310.3839669-4-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ext4.h | 3 ++- fs/ext4/inode.c | 8 +++++++- fs/ext4/ioctl.c | 3 ++- 3 files changed, 11 insertions(+), 3 deletions(-) --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2608,7 +2608,8 @@ int do_journal_get_write_access(handle_t typedef enum { EXT4_IGET_NORMAL = 0, EXT4_IGET_SPECIAL = 0x0001, /* OK to iget a system inode */ - EXT4_IGET_HANDLE = 0x0002 /* Inode # is from a handle */ + EXT4_IGET_HANDLE = 0x0002, /* Inode # is from a handle */ + EXT4_IGET_BAD = 0x0004 /* Allow to iget a bad inode */ } ext4_iget_flags; extern struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5192,8 +5192,14 @@ struct inode *__ext4_iget(struct super_b if (IS_CASEFOLDED(inode) && !ext4_has_feature_casefold(inode->i_sb)) ext4_error_inode(inode, function, line, 0, "casefold flag without casefold feature"); - brelse(iloc.bh); + if (is_bad_inode(inode) && !(flags & EXT4_IGET_BAD)) { + ext4_error_inode(inode, function, line, 0, + "bad inode without EXT4_IGET_BAD flag"); + ret = -EUCLEAN; + goto bad_inode; + } + brelse(iloc.bh); unlock_new_inode(inode); return inode; --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -121,7 +121,8 @@ static long swap_inode_boot_loader(struc blkcnt_t blocks; unsigned short bytes; - inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO, EXT4_IGET_SPECIAL); + inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO, + EXT4_IGET_SPECIAL | EXT4_IGET_BAD); if (IS_ERR(inode_bl)) return PTR_ERR(inode_bl); ei_bl = EXT4_I(inode_bl);