KEYS: use kfree_sensitive with key

    key might contain private part of the key, so better use
    kfree_sensitive to free it

    Signed-off-by: Mahmoud Adam <[email protected]>
    Signed-off-by: Herbert Xu <[email protected]>

Back-port of upstream commit: 9f3fa6b

Signed-off-by: Jeremy Allison <[email protected]>

Author: jallisonciq

crypto/asymmetric_keys/public_key.c

@@ -139,7 +139,7 @@ int public_key_verify_signature(const struct public_key *pkey,
 		ret = -EKEYREJECTED;
 
 out_free_output:
-	kfree(output);
+	kfree_sensitive(output);
 error_free_req:
 	akcipher_request_free(req);
 error_free_tfm: