From: Richard Weinberger <richard@nod.at>
Date: Fri, 30 Sep 2016 05:49:55 +0000 (-0400)
Subject: ext4: require encryption feature for EXT4_IOC_SET_ENCRYPTION_POLICY
X-Git-Tag: v4.9-rc1~86^2~6
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=9a200d075e5d05be1fcad4547a0f8aee4e2f9a04;p=users%2Fjedix%2Flinux-maple.git

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 c64239b24c2fc..22abf7aeb25d0 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -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)))