crypto: algapi - fix NULL dereference in crypto_remove_spawns()

[pandora-kernel.git] / crypto / algapi.c

diff --git a/crypto/algapi.c b/crypto/algapi.c
index 2f19548..49e1268 100644 (file)
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -163,6 +163,18 @@ void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
 
                        spawn->alg = NULL;
                        spawns = &inst->alg.cra_users;
+
+                       /*
+                        * We may encounter an unregistered instance here, since
+                        * an instance's spawns are set up prior to the instance
+                        * being registered.  An unregistered instance will have
+                        * NULL ->cra_users.next, since ->cra_users isn't
+                        * properly initialized until registration.  But an
+                        * unregistered instance cannot have any users, so treat
+                        * it the same as ->cra_users being empty.
+                        */
+                       if (spawns->next == NULL)
+                               break;
                }
        } while ((spawns = crypto_more_spawns(alg, &stack, &top,
                                              &secondary_spawns)));