From 0642ea2409f3bfa105570e12854b8e2628db6835 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Sun, 4 Aug 2019 17:56:43 +0800 Subject: [PATCH] ext4 crypto: fix to check feature status before get policy When getting fscrypt policy via EXT4_IOC_GET_ENCRYPTION_POLICY, if encryption feature is off, it's better to return EOPNOTSUPP instead of ENODATA, so let's add ext4_has_feature_encrypt() to do the check for that. This makes it so that all fscrypt ioctls consistently check for the encryption feature, and makes ext4 consistent with f2fs in this regard. Signed-off-by: Chao Yu [EB - removed unneeded braces, updated the documentation, and added more explanation to commit message] Signed-off-by: Eric Biggers --- Documentation/filesystems/fscrypt.rst | 3 ++- fs/ext4/ioctl.c | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 4289c29d7c5a..8a0700af9596 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -562,7 +562,8 @@ FS_IOC_GET_ENCRYPTION_POLICY_EX can fail with the following errors: or this kernel is too old to support FS_IOC_GET_ENCRYPTION_POLICY_EX (try FS_IOC_GET_ENCRYPTION_POLICY instead) - ``EOPNOTSUPP``: the kernel was not configured with encryption - support for this filesystem + support for this filesystem, or the filesystem superblock has not + had encryption enabled on it - ``EOVERFLOW``: the file is encrypted and uses a recognized encryption policy version, but the policy struct does not fit into the provided buffer diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index fe5a4b13f939..5703d607f5af 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -1113,6 +1113,8 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) #endif } case EXT4_IOC_GET_ENCRYPTION_POLICY: + if (!ext4_has_feature_encrypt(sb)) + return -EOPNOTSUPP; return fscrypt_ioctl_get_policy(filp, (void __user *)arg); case FS_IOC_GET_ENCRYPTION_POLICY_EX: