ecryptfs: fix dereference of NULL user_key_payload

[mirror_ubuntu-artful-kernel.git] / fs / ecryptfs / ecryptfs_kernel.h

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 9c351bf757b20e037f39aeadf0fa0ed12f963db6..3fbc0ff79699dde5cca295262591b2cb5aafcced 100644 (file)
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -84,11 +84,16 @@ struct ecryptfs_page_crypt_context {
 static inline struct ecryptfs_auth_tok *
 ecryptfs_get_encrypted_key_payload_data(struct key *key)
 {
-       if (key->type == &key_type_encrypted)
-               return (struct ecryptfs_auth_tok *)
-                       (&((struct encrypted_key_payload *)key->payload.data[0])->payload_data);
-       else
+       struct encrypted_key_payload *payload;
+
+       if (key->type != &key_type_encrypted)
                return NULL;
+
+       payload = key->payload.data[0];
+       if (!payload)
+               return ERR_PTR(-EKEYREVOKED);
+
+       return (struct ecryptfs_auth_tok *)payload->payload_data;
 }
 
 static inline struct key *ecryptfs_get_encrypted_key(char *sig)
@@ -114,12 +119,17 @@ static inline struct ecryptfs_auth_tok *
 ecryptfs_get_key_payload_data(struct key *key)
 {
        struct ecryptfs_auth_tok *auth_tok;
+       struct user_key_payload *ukp;
 
        auth_tok = ecryptfs_get_encrypted_key_payload_data(key);
-       if (!auth_tok)
-               return (struct ecryptfs_auth_tok *)user_key_payload_locked(key)->data;
-       else
+       if (auth_tok)
                return auth_tok;
+
+       ukp = user_key_payload_locked(key);
+       if (!ukp)
+               return ERR_PTR(-EKEYREVOKED);
+
+       return (struct ecryptfs_auth_tok *)ukp->data;
 }
 
 #define ECRYPTFS_MAX_KEYSET_SIZE 1024