Merge tag 'keys-request-20190626' of git://git.kernel.org/pub/scm/linux/kernel/git...

[platform/kernel/linux-rpi.git] / security / keys / request_key_auth.c

diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 3d8616f..5456c0c 100644 (file)
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -54,7 +54,7 @@ static void request_key_auth_free_preparse(struct key_preparsed_payload *prep)
 static int request_key_auth_instantiate(struct key *key,
                                        struct key_preparsed_payload *prep)
 {
-       key->payload.data[0] = (struct request_key_auth *)prep->data;
+       rcu_assign_keypointer(key, (struct request_key_auth *)prep->data);
        return 0;
 }
 
@@ -64,7 +64,7 @@ static int request_key_auth_instantiate(struct key *key,
 static void request_key_auth_describe(const struct key *key,
                                      struct seq_file *m)
 {
-       struct request_key_auth *rka = get_request_key_auth(key);
+       struct request_key_auth *rka = dereference_key_rcu(key);
 
        seq_puts(m, "key:");
        seq_puts(m, key->description);
@@ -79,7 +79,7 @@ static void request_key_auth_describe(const struct key *key,
 static long request_key_auth_read(const struct key *key,
                                  char __user *buffer, size_t buflen)
 {
-       struct request_key_auth *rka = get_request_key_auth(key);
+       struct request_key_auth *rka = dereference_key_locked(key);
        size_t datalen;
        long ret;
 
@@ -98,23 +98,6 @@ static long request_key_auth_read(const struct key *key,
        return ret;
 }
 
-/*
- * Handle revocation of an authorisation token key.
- *
- * Called with the key sem write-locked.
- */
-static void request_key_auth_revoke(struct key *key)
-{
-       struct request_key_auth *rka = get_request_key_auth(key);
-
-       kenter("{%d}", key->serial);
-
-       if (rka->cred) {
-               put_cred(rka->cred);
-               rka->cred = NULL;
-       }
-}
-
 static void free_request_key_auth(struct request_key_auth *rka)
 {
        if (!rka)
@@ -128,15 +111,42 @@ static void free_request_key_auth(struct request_key_auth *rka)
 }
 
 /*
+ * Dispose of the request_key_auth record under RCU conditions
+ */
+static void request_key_auth_rcu_disposal(struct rcu_head *rcu)
+{
+       struct request_key_auth *rka =
+               container_of(rcu, struct request_key_auth, rcu);
+
+       free_request_key_auth(rka);
+}
+
+/*
+ * Handle revocation of an authorisation token key.
+ *
+ * Called with the key sem write-locked.
+ */
+static void request_key_auth_revoke(struct key *key)
+{
+       struct request_key_auth *rka = dereference_key_locked(key);
+
+       kenter("{%d}", key->serial);
+       rcu_assign_keypointer(key, NULL);
+       call_rcu(&rka->rcu, request_key_auth_rcu_disposal);
+}
+
+/*
  * Destroy an instantiation authorisation token key.
  */
 static void request_key_auth_destroy(struct key *key)
 {
-       struct request_key_auth *rka = get_request_key_auth(key);
+       struct request_key_auth *rka = rcu_access_pointer(key->payload.rcu_data0);
 
        kenter("{%d}", key->serial);
-
-       free_request_key_auth(rka);
+       if (rka) {
+               rcu_assign_keypointer(key, NULL);
+               call_rcu(&rka->rcu, request_key_auth_rcu_disposal);
+       }
 }
 
 /*
@@ -245,7 +255,9 @@ struct key *key_get_instantiation_authkey(key_serial_t target_id)
 
        ctx.index_key.desc_len = sprintf(description, "%x", target_id);
 
-       authkey_ref = search_process_keyrings(&ctx);
+       rcu_read_lock();
+       authkey_ref = search_process_keyrings_rcu(&ctx);
+       rcu_read_unlock();
 
        if (IS_ERR(authkey_ref)) {
                authkey = ERR_CAST(authkey_ref);