[PATCH 3.16.y-ckt 095/216] KEYS: Fix stale key registration at error path

[Luis Henriques]

3.16.7-ckt4 -stable review patch.  If anyone has any objections, please let me know.

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

From: Takashi Iwai <tiwai at suse.de>

commit b26bdde5bb27f3f900e25a95e33a0c476c8c2c48 upstream.

When loading encrypted-keys module, if the last check of
aes_get_sizes() in init_encrypted() fails, the driver just returns an
error without unregistering its key type.  This results in the stale
entry in the list.  In addition to memory leaks, this leads to a kernel
crash when registering a new key type later.

This patch fixes the problem by swapping the calls of aes_get_sizes()
and register_key_type(), and releasing resources properly at the error
paths.

Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=908163
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Mimi Zohar <zohar at linux.vnet.ibm.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 security/keys/encrypted-keys/encrypted.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 5fe443d120af..556c43df6636 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -1018,10 +1018,13 @@ static int __init init_encrypted(void)
 	ret = encrypted_shash_alloc();
 	if (ret < 0)
 		return ret;
+	ret = aes_get_sizes();
+	if (ret < 0)
+		goto out;
 	ret = register_key_type(&key_type_encrypted);
 	if (ret < 0)
 		goto out;
-	return aes_get_sizes();
+	return 0;
 out:
 	encrypted_shash_release();
 	return ret;
-- 
2.1.4