Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching

torvalds · torvalds · commit 3933ec73cd9b · 2018-08-20T16:10:47.000-07:00
Pull livepatching updates from Jiri Kosina:
 "Code cleanups from Kamalesh Babulal"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: Validate module/old func name length
  livepatch: Remove reliable stacktrace check in klp_try_switch_task()
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
@@ -678,6 +678,9 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func)
 	if (!func->old_name || !func->new_func)
 		return -EINVAL;
 
+	if (strlen(func->old_name) >= KSYM_NAME_LEN)
+		return -EINVAL;
+
 	INIT_LIST_HEAD(&func->stack_node);
 	func->patched = false;
 	func->transition = false;
@@ -751,6 +754,9 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
 	if (!obj->funcs)
 		return -EINVAL;
 
+	if (klp_is_module(obj) && strlen(obj->name) >= MODULE_NAME_LEN)
+		return -EINVAL;
+
 	obj->patched = false;
 	obj->mod = NULL;
 
diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
@@ -309,13 +309,6 @@ static bool klp_try_switch_task(struct task_struct *task)
 	if (task->patch_state == klp_target_state)
 		return true;
 
-	/*
-	 * For arches which don't have reliable stack traces, we have to rely
-	 * on other methods (e.g., switching tasks at kernel exit).
-	 */
-	if (!klp_have_reliable_stack())
-		return false;
-
 	/*
 	 * Now try to check the stack for any to-be-patched or to-be-unpatched
 	 * functions.  If all goes well, switch the task to the target patch
