keys: Fix dependency loop between construction record and auth key

[mirror_ubuntu-bionic-kernel.git] / security / keys / request_key.c

diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 7385536986497801e4c1f23606887c8772ed119e..1a547cec8385e7a925f59252dfb8deccbcb1484c 100644 (file)
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -18,31 +18,30 @@
 #include <linux/keyctl.h>
 #include <linux/slab.h>
 #include "internal.h"
+#include <keys/request_key_auth-type.h>
 
 #define key_negative_timeout   60      /* default timeout on a negative key's existence */
 
 /**
  * complete_request_key - Complete the construction of a key.
- * @cons: The key construction record.
+ * @auth_key: The authorisation key.
  * @error: The success or failute of the construction.
  *
  * Complete the attempt to construct a key.  The key will be negated
  * if an error is indicated.  The authorisation key will be revoked
  * unconditionally.
  */
-void complete_request_key(struct key_construction *cons, int error)
+void complete_request_key(struct key *authkey, int error)
 {
-       kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error);
+       struct request_key_auth *rka = get_request_key_auth(authkey);
+       struct key *key = rka->target_key;
+
+       kenter("%d{%d},%d", authkey->serial, key->serial, error);
 
        if (error < 0)
-               key_negate_and_link(cons->key, key_negative_timeout, NULL,
-                                   cons->authkey);
+               key_negate_and_link(key, key_negative_timeout, NULL, authkey);
        else
-               key_revoke(cons->authkey);
-
-       key_put(cons->key);
-       key_put(cons->authkey);
-       kfree(cons);
+               key_revoke(authkey);
 }
 EXPORT_SYMBOL(complete_request_key);
 
@@ -91,21 +90,19 @@ static int call_usermodehelper_keys(const char *path, char **argv, char **envp,
  * Request userspace finish the construction of a key
  * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
  */
-static int call_sbin_request_key(struct key_construction *cons,
-                                const char *op,
-                                void *aux)
+static int call_sbin_request_key(struct key *authkey, void *aux)
 {
        static char const request_key[] = "/sbin/request-key";
+       struct request_key_auth *rka = get_request_key_auth(authkey);
        const struct cred *cred = current_cred();
        key_serial_t prkey, sskey;
-       struct key *key = cons->key, *authkey = cons->authkey, *keyring,
-               *session;
+       struct key *key = rka->target_key, *keyring, *session;
        char *argv[9], *envp[3], uid_str[12], gid_str[12];
        char key_str[12], keyring_str[3][12];
        char desc[20];
        int ret, i;
 
-       kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
+       kenter("{%d},{%d},%s", key->serial, authkey->serial, rka->op);
 
        ret = install_user_keyrings();
        if (ret < 0)
@@ -163,7 +160,7 @@ static int call_sbin_request_key(struct key_construction *cons,
        /* set up the argument list */
        i = 0;
        argv[i++] = (char *)request_key;
-       argv[i++] = (char *) op;
+       argv[i++] = (char *)rka->op;
        argv[i++] = key_str;
        argv[i++] = uid_str;
        argv[i++] = gid_str;
@@ -191,7 +188,7 @@ error_link:
        key_put(keyring);
 
 error_alloc:
-       complete_request_key(cons, ret);
+       complete_request_key(authkey, ret);
        kleave(" = %d", ret);
        return ret;
 }
@@ -205,42 +202,31 @@ static int construct_key(struct key *key, const void *callout_info,
                         size_t callout_len, void *aux,
                         struct key *dest_keyring)
 {
-       struct key_construction *cons;
        request_key_actor_t actor;
        struct key *authkey;
        int ret;
 
        kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
 
-       cons = kmalloc(sizeof(*cons), GFP_KERNEL);
-       if (!cons)
-               return -ENOMEM;
-
        /* allocate an authorisation key */
-       authkey = request_key_auth_new(key, callout_info, callout_len,
+       authkey = request_key_auth_new(key, "create", callout_info, callout_len,
                                       dest_keyring);
-       if (IS_ERR(authkey)) {
-               kfree(cons);
-               ret = PTR_ERR(authkey);
-               authkey = NULL;
-       } else {
-               cons->authkey = key_get(authkey);
-               cons->key = key_get(key);
+       if (IS_ERR(authkey))
+               return PTR_ERR(authkey);
 
-               /* make the call */
-               actor = call_sbin_request_key;
-               if (key->type->request_key)
-                       actor = key->type->request_key;
+       /* Make the call */
+       actor = call_sbin_request_key;
+       if (key->type->request_key)
+               actor = key->type->request_key;
 
-               ret = actor(cons, "create", aux);
+       ret = actor(authkey, aux);
 
-               /* check that the actor called complete_request_key() prior to
-                * returning an error */
-               WARN_ON(ret < 0 &&
-                       !test_bit(KEY_FLAG_REVOKED, &authkey->flags));
-               key_put(authkey);
-       }
+       /* check that the actor called complete_request_key() prior to
+        * returning an error */
+       WARN_ON(ret < 0 &&
+               !test_bit(KEY_FLAG_REVOKED, &authkey->flags));
 
+       key_put(authkey);
        kleave(" = %d", ret);
        return ret;
 }
@@ -275,7 +261,7 @@ static int construct_get_dest_keyring(struct key **_dest_keyring)
                        if (cred->request_key_auth) {
                                authkey = cred->request_key_auth;
                                down_read(&authkey->sem);
-                               rka = authkey->payload.data[0];
+                               rka = get_request_key_auth(authkey);
                                if (!test_bit(KEY_FLAG_REVOKED,
                                              &authkey->flags))
                                        dest_keyring =