From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41111 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934085AbcILPdD (ORCPT ); Mon, 12 Sep 2016 11:33:03 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Biggers , Theodore Tso Subject: [PATCH 4.7 47/59] fscrypto: only allow setting encryption policy on directories Date: Mon, 12 Sep 2016 17:30:07 +0200 Message-Id: <20160912152130.749279772@linuxfoundation.org> In-Reply-To: <20160912152128.765864031@linuxfoundation.org> References: <20160912152128.765864031@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit 002ced4be6429918800ce3e41d5cbc2d7c01822c upstream. The FS_IOC_SET_ENCRYPTION_POLICY ioctl allowed setting an encryption policy on nondirectory files. This was unintentional, and in the case of nonempty regular files did not behave as expected because existing data was not actually encrypted by the ioctl. In the case of ext4, the user could also trigger filesystem errors in ->empty_dir(), e.g. due to mismatched "directory" checksums when the kernel incorrectly tried to interpret a regular file as a directory. This bug affected ext4 with kernels v4.8-rc1 or later and f2fs with kernels v4.6 and later. It appears that older kernels only permitted directories and that the check was accidentally lost during the refactoring to share the file encryption code between ext4 and f2fs. This patch restores the !S_ISDIR() check that was present in older kernels. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/crypto/policy.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -102,6 +102,8 @@ int fscrypt_process_policy(struct inode return -EINVAL; if (!inode_has_encryption_context(inode)) { + if (!S_ISDIR(inode->i_mode)) + return -EINVAL; if (!inode->i_sb->s_cop->empty_dir) return -EOPNOTSUPP; if (!inode->i_sb->s_cop->empty_dir(inode))