From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 72C301C03 for ; Mon, 20 Mar 2023 15:11:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9069C4339B; Mon, 20 Mar 2023 15:11:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1679325078; bh=+IHKjxMRq+xQiERRykX1ADAudBxEAWEx2ropZEXZbE8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gJaWYembRRqvCn+HfisEw1YB03BIWe6r9ttLgSq5K30noDXuMqUQ8F0TgEV8zch1y tczcP7dkAyD976JIRZVzIGbnqwWg76WtqDnn1n4N+7eSMYeA9+hSWMC4fxDjbiHyHl +Hakrhj6CaugYWZCkuPgVOyQ635RIYreTd4Jsw4w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Lu=C3=ADs=20Henriques?= , Theodore Tso , Baokun Li , Jan Kara , Sasha Levin Subject: [PATCH 5.15 066/115] ext4: fail ext4_iget if special inode unallocated Date: Mon, 20 Mar 2023 15:54:38 +0100 Message-Id: <20230320145452.175177331@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230320145449.336983711@linuxfoundation.org> References: <20230320145449.336983711@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Baokun Li [ Upstream commit 5cd740287ae5e3f9d1c46f5bfe8778972fd6d3fe ] In ext4_fill_super(), EXT4_ORPHAN_FS flag is cleared after ext4_orphan_cleanup() is executed. Therefore, when __ext4_iget() is called to get an inode whose i_nlink is 0 when the flag exists, no error is returned. If the inode is a special inode, a null pointer dereference may occur. If the value of i_nlink is 0 for any inodes (except boot loader inodes) got by using the EXT4_IGET_SPECIAL flag, the current file system is corrupted. Therefore, make the ext4_iget() function return an error if it gets such an abnormal special inode. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199179 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216541 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216539 Reported-by: Luís Henriques Suggested-by: Theodore Ts'o Signed-off-by: Baokun Li Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230107032126.4165860-2-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/inode.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index b2600e8021b1d..a39d5cca41212 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4636,13 +4636,6 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, goto bad_inode; raw_inode = ext4_raw_inode(&iloc); - if ((ino == EXT4_ROOT_INO) && (raw_inode->i_links_count == 0)) { - ext4_error_inode(inode, function, line, 0, - "iget: root inode unallocated"); - ret = -EFSCORRUPTED; - goto bad_inode; - } - if ((flags & EXT4_IGET_HANDLE) && (raw_inode->i_links_count == 0) && (raw_inode->i_mode == 0)) { ret = -ESTALE; @@ -4715,11 +4708,16 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, * NeilBrown 1999oct15 */ if (inode->i_nlink == 0) { - if ((inode->i_mode == 0 || + if ((inode->i_mode == 0 || flags & EXT4_IGET_SPECIAL || !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) && ino != EXT4_BOOT_LOADER_INO) { - /* this inode is deleted */ - ret = -ESTALE; + /* this inode is deleted or unallocated */ + if (flags & EXT4_IGET_SPECIAL) { + ext4_error_inode(inode, function, line, 0, + "iget: special inode unallocated"); + ret = -EFSCORRUPTED; + } else + ret = -ESTALE; goto bad_inode; } /* The only unlinked inodes we let through here have -- 2.39.2