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 106C3C46467 for ; Mon, 16 Jan 2023 16:47:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233855AbjAPQrK (ORCPT ); Mon, 16 Jan 2023 11:47:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233733AbjAPQqZ (ORCPT ); Mon, 16 Jan 2023 11:46:25 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81BA2298F4 for ; Mon, 16 Jan 2023 08:34:27 -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 ams.source.kernel.org (Postfix) with ESMTPS id 444B0B8105D for ; Mon, 16 Jan 2023 16:34:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3F02C433EF; Mon, 16 Jan 2023 16:34:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673886865; bh=1dqAHGRbfaQnDFsQsvdy3d0rpymkmJrWcZC5DZFVBz4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GRa7dHQxTHqB3yM7K5qoZrRqHEum2eaS6EzzcKZcbr8FblpJlIdnNmmykja83GysO b3tHr0Lq01U4lVgJw24UDXGEJmTQZmY0IWihkGTeVcPMR0H1sC3iQaZ61bbdzOk3v8 Lnni9mMdag8O+/NBVxl6HbJN2zZysytlhc2mPdt8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+ba9dac45bc76c490b7c3@syzkaller.appspotmail.com, Eric Biggers , Theodore Tso , stable@kernel.org Subject: [PATCH 5.4 592/658] ext4: dont allow journal inode to have encrypt flag Date: Mon, 16 Jan 2023 16:51:20 +0100 Message-Id: <20230116154936.570722114@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: Eric Biggers commit 105c78e12468413e426625831faa7db4284e1fec upstream. Mounting a filesystem whose journal inode has the encrypt flag causes a NULL dereference in fscrypt_limit_io_blocks() when the 'inlinecrypt' mount option is used. The problem is that when jbd2_journal_init_inode() calls bmap(), it eventually finds its way into ext4_iomap_begin(), which calls fscrypt_limit_io_blocks(). fscrypt_limit_io_blocks() requires that if the inode is encrypted, then its encryption key must already be set up. That's not the case here, since the journal inode is never "opened" like a normal file would be. Hence the crash. A reproducer is: mkfs.ext4 -F /dev/vdb debugfs -w /dev/vdb -R "set_inode_field <8> flags 0x80808" mount /dev/vdb /mnt -o inlinecrypt To fix this, make ext4 consider journal inodes with the encrypt flag to be invalid. (Note, maybe other flags should be rejected on the journal inode too. For now, this is just the minimal fix for the above issue.) I've marked this as fixing the commit that introduced the call to fscrypt_limit_io_blocks(), since that's what made an actual crash start being possible. But this fix could be applied to any version of ext4 that supports the encrypt feature. Reported-by: syzbot+ba9dac45bc76c490b7c3@syzkaller.appspotmail.com Fixes: 38ea50daa7a4 ("ext4: support direct I/O with fscrypt using blk-crypto") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221102053312.189962-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4836,7 +4836,7 @@ static struct inode *ext4_get_journal_in jbd_debug(2, "Journal inode found at %p: %lld bytes\n", journal_inode, journal_inode->i_size); - if (!S_ISREG(journal_inode->i_mode)) { + if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) { ext4_msg(sb, KERN_ERR, "invalid journal inode"); iput(journal_inode); return NULL;