From: Christopher Faulet <cfaulet@haproxy.com>
Date: Mon, 12 Apr 2021 10:24:47 +0000 (+0200)
Subject: BUG/MINOR: hlua: Fix memory leaks on error path when registering a task
X-Git-Tag: v2.4-dev17~132
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5294ec0708ab686e59c48252d1ef6e8c7e40972b;p=thirdparty%2Fhaproxy.git

BUG/MINOR: hlua: Fix memory leaks on error path when registering a task

When an error occurred in hlua_register_task(), the allocated lua context
and task must be released to avoid memory leaks.

This patch may be backported in all stable versions.
---

diff --git a/src/hlua.c b/src/hlua.c
index c147fc3752..660c967074 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -6402,8 +6402,8 @@ __LJMP static int hlua_register_init(lua_State *L)
  */
 static int hlua_register_task(lua_State *L)
 {
-	struct hlua *hlua;
-	struct task *task;
+	struct hlua *hlua = NULL;
+	struct task *task = NULL;
 	int ref;
 	int state_id;
 
@@ -6424,7 +6424,7 @@ static int hlua_register_task(lua_State *L)
 
 	hlua = pool_alloc(pool_head_hlua);
 	if (!hlua)
-		WILL_LJMP(luaL_error(L, "Lua out of memory error."));
+		goto alloc_error;
 	HLUA_INIT(hlua);
 
 	/* We are in the common lua state, execute the task anywhere,
@@ -6435,13 +6435,13 @@ static int hlua_register_task(lua_State *L)
 	else
 		task = task_new(tid_bit);
 	if (!task)
-		WILL_LJMP(luaL_error(L, "Lua out of memory error."));
+		goto alloc_error;
 
 	task->context = hlua;
 	task->process = hlua_process_task;
 
 	if (!hlua_ctx_init(hlua, state_id, task, 1))
-		WILL_LJMP(luaL_error(L, "Lua out of memory error."));
+		goto alloc_error;
 
 	/* Restore the function in the stack. */
 	lua_rawgeti(hlua->T, LUA_REGISTRYINDEX, ref);
@@ -6451,6 +6451,12 @@ static int hlua_register_task(lua_State *L)
 	task_schedule(task, now_ms);
 
 	return 0;
+
+  alloc_error:
+	task_destroy(task);
+	hlua_ctx_destroy(hlua);
+	WILL_LJMP(luaL_error(L, "Lua out of memory error."));
+	return 0; /* Never reached */
 }
 
 /* Wrapper called by HAProxy to execute an LUA converter. This wrapper