[PATCH 4.4 47/47] ext4: dont allow encrypted operations without keys

From: Greg Kroah-Hartman
Date: Tue Oct 10 2017 - 17:06:57 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Theodore Ts'o <tytso@xxxxxxx>

commit 173b8439e1ba362007315868928bf9d26e5cc5a6 upstream.

While we allow deletes without the key, the following should not be
permitted:

# cd /vdc/encrypted-dir-without-key
# ls -l
total 4
-rw-r--r-- 1 root root 0 Dec 27 22:35 6,LKNRJsp209FbXoSvJWzB
-rw-r--r-- 1 root root 286 Dec 27 22:35 uRJ5vJh9gE7vcomYMqTAyD
# mv uRJ5vJh9gE7vcomYMqTAyD 6,LKNRJsp209FbXoSvJWzB

Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>


---
fs/ext4/namei.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3506,6 +3506,12 @@ static int ext4_rename(struct inode *old
int credits;
u8 old_file_type;

+ if ((ext4_encrypted_inode(old_dir) &&
+ !ext4_has_encryption_key(old_dir)) ||
+ (ext4_encrypted_inode(new_dir) &&
+ !ext4_has_encryption_key(new_dir)))
+ return -ENOKEY;
+
retval = dquot_initialize(old.dir);
if (retval)
return retval;
@@ -3706,6 +3712,12 @@ static int ext4_cross_rename(struct inod
u8 new_file_type;
int retval;

+ if ((ext4_encrypted_inode(old_dir) &&
+ !ext4_has_encryption_key(old_dir)) ||
+ (ext4_encrypted_inode(new_dir) &&
+ !ext4_has_encryption_key(new_dir)))
+ return -ENOKEY;
+
if ((ext4_encrypted_inode(old_dir) ||
ext4_encrypted_inode(new_dir)) &&
(old_dir != new_dir) &&