ext4: require encryption feature for EXT4_IOC_SET_ENCRYPTION_POLICY

...otherwise an user can enable encryption for certain files even
when the filesystem is unable to support it.
Such a case would be a filesystem created by mkfs.ext4's default
settings, 1KiB block size. Ext4 supports encyption only when block size
is equal to PAGE_SIZE.
But this constraint is only checked when the encryption feature flag
is set.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Richard Weinberger 2016-09-30 01:49:55 -04:00 committed by Theodore Ts'o
parent 55be3145d1
commit 9a200d075e
1 changed files with 3 additions and 0 deletions

View File

@ -769,6 +769,9 @@ resizefs_out:
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct fscrypt_policy policy;
if (!ext4_has_feature_encrypt(sb))
return -EOPNOTSUPP;
if (copy_from_user(&policy,
(struct fscrypt_policy __user *)arg,
sizeof(policy)))