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>
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index c64239b..22abf7a 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -769,6 +769,9 @@
#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)))