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Commit 45b1509e authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

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: default avatarChao Yu <yuchao0@huawei.com>
[EB - removed unneeded braces, updated the documentation, and
      added more explanation to commit message]
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
parent c0751a1b

Documentation/filesystems/fscrypt.rst

+2 −1
Original line number Diff line number Diff line
@@ -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

fs/ext4/ioctl.c

+2 −0
Original line number Diff line number Diff line
@@ -981,6 +981,8 @@ 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: