kern: Fix crash.

Check receiver in task_create.  Fixes a crash when sending that
message to a non-task port.

* kern/bootstrap.c (boot_script_task_create): Use the new function.
* kern/task.c (task_create): Rename to task_create_internal, create a
new function in its place that checks the receiver first.
* kern/task.h (task_create_internal): New prototype.

1 files changed, 27 insertions, 1 deletions

diff --git a/kern/task.c b/kern/task.c
index 1874af69..681ce872 100644
--- a/kern/task.c
+++ b/kern/task.c
@@ -73,16 +73,42 @@ void task_init(void)
 	 * Task_create must assign to kernel_task as a side effect,
 	 * for other initialization. (:-()
 	 */
-	(void) task_create(TASK_NULL, FALSE, &kernel_task);
+	(void) task_create_kernel(TASK_NULL, FALSE, &kernel_task);
 	(void) task_set_name(kernel_task, "gnumach");
 	vm_map_set_name(kernel_map, kernel_task->name);
 }
 
+int
+task_ledger_acquire (task_t task, enum ledger_kind kind)
+{
+	return ledger_acquire (task->ledgers, kind);
+}
+
+void
+task_ledger_release (task_t task, enum ledger_kind kind)
+{
+	ledger_release (task->ledgers, kind);
+}
+
+
 kern_return_t task_create(
 	task_t		parent_task,
 	boolean_t	inherit_memory,
 	task_t		*child_task)		/* OUT */
 {
+	if (parent_task == TASK_NULL)
+		return KERN_INVALID_TASK;
+
+	return task_create_kernel (parent_task, inherit_memory,
+				   child_task);
+}
+
+kern_return_t
+task_create_kernel(
+	task_t		parent_task,
+	boolean_t	inherit_memory,
+	task_t		*child_task)		/* OUT */
+{
 	task_t		new_task;
 	processor_set_t	pset;
 #if FAST_TAS