From: Vsevolod Stakhov <vsevolod@rspamd.com>
Date: Sat, 6 Dec 2025 14:18:20 +0000 (+0000)
Subject: [Fix] Handle Lua 5.4 require returning two values
X-Git-Tag: 3.14.2~12
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5b62d047fa2bfef42792fc4e7d75f8f31a6174a4;p=thirdparty%2Frspamd.git

[Fix] Handle Lua 5.4 require returning two values

Lua 5.4's require() returns both the module and the file path, while
LuaJIT returns only the module. Save stack top before luaL_dostring
and restore to top+1 after to keep only the first return value.
---

diff --git a/src/libstat/stat_config.c b/src/libstat/stat_config.c
index 5ada7d4681..ecc96c1741 100644
--- a/src/libstat/stat_config.c
+++ b/src/libstat/stat_config.c
@@ -180,14 +180,14 @@ void rspamd_stat_init(struct rspamd_config *cfg, struct ev_loop *ev_base)
 	stat_ctx->lua_stat_tokens_ref = -1;
 
 	/* Interact with lua_stat */
+	int lua_stat_top = lua_gettop(L);
 	if (luaL_dostring(L, "return require \"lua_stat\"") != 0) {
 		msg_err_config("cannot require lua_stat: %s",
 					   lua_tostring(L, -1));
 	}
 	else {
-#if LUA_VERSION_NUM >= 504
-		lua_settop(L, -2);
-#endif
+		/* Lua 5.4's require returns 2 values (module + path), keep only first */
+		lua_settop(L, lua_stat_top + 1);
 		if (lua_type(L, -1) != LUA_TTABLE) {
 			msg_err_config("lua stat must return "
 						   "table and not %s",
diff --git a/src/lua/lua_config.c b/src/lua/lua_config.c
index c7534980a8..b863e11d72 100644
--- a/src/lua/lua_config.c
+++ b/src/lua/lua_config.c
@@ -5115,11 +5115,14 @@ lua_config_register_re_selector(lua_State *L)
 			}
 		}
 
+		int selector_top = lua_gettop(L);
 		if (luaL_dostring(L, "return require \"lua_selectors\"") != 0) {
 			msg_warn_config("cannot require lua_selectors: %s",
 							lua_tostring(L, -1));
 		}
 		else {
+			/* Lua 5.4's require returns 2 values (module + path), keep only first */
+			lua_settop(L, selector_top + 1);
 			if (lua_type(L, -1) != LUA_TTABLE) {
 				msg_warn_config("lua selectors must return "
 								"table and not %s",
@@ -5541,11 +5544,14 @@ lua_config_register_re_selector_scoped(lua_State *L)
 			}
 		}
 
+		int selector_top = lua_gettop(L);
 		if (luaL_dostring(L, "return require \"lua_selectors\"") != 0) {
 			msg_warn_config("cannot require lua_selectors: %s",
 							lua_tostring(L, -1));
 		}
 		else {
+			/* Lua 5.4's require returns 2 values (module + path), keep only first */
+			lua_settop(L, selector_top + 1);
 			if (lua_type(L, -1) != LUA_TTABLE) {
 				msg_warn_config("lua selectors must return "
 								"table and not %s",
diff --git a/src/plugins/fuzzy_check.c b/src/plugins/fuzzy_check.c
index 030d14a7b3..75da5640da 100644
--- a/src/plugins/fuzzy_check.c
+++ b/src/plugins/fuzzy_check.c
@@ -2609,15 +2609,15 @@ int fuzzy_check_module_config(struct rspamd_config *cfg, bool validate)
 	fuzzy_module_ctx->cleanup_rules_ref = -1;
 
 	/* Interact with lua_fuzzy */
+	int lua_fuzzy_top = lua_gettop(L);
 	if (luaL_dostring(L, "return require \"lua_fuzzy\"") != 0) {
 		msg_err_config("cannot require lua_fuzzy: %s",
 					   lua_tostring(L, -1));
 		fuzzy_module_ctx->enabled = FALSE;
 	}
 	else {
-#if LUA_VERSION_NUM >= 504
-		lua_settop(L, -2);
-#endif
+		/* Lua 5.4's require returns 2 values (module + path), keep only first */
+		lua_settop(L, lua_fuzzy_top + 1);
 		if (lua_type(L, -1) != LUA_TTABLE) {
 			msg_err_config("lua fuzzy must return "
 						   "table and not %s",
diff --git a/src/rspamadm/rspamadm.c b/src/rspamadm/rspamadm.c
index 655b8606d0..e3b95895c7 100644
--- a/src/rspamadm/rspamadm.c
+++ b/src/rspamadm/rspamadm.c
@@ -248,12 +248,17 @@ rspamadm_execute_lua_ucl_subr(int argc, char **argv,
 						script_name);
 	}
 
+	int top = lua_gettop(L);
+
 	if (luaL_dostring(L, str) != 0) {
 		msg_err("cannot execute lua script %s: %s",
 				str, lua_tostring(L, -1));
 		return FALSE;
 	}
 	else {
+		/* Lua 5.4's require returns 2 values (module + path), keep only first */
+		lua_settop(L, top + 1);
+
 		if (lua_type(L, -1) == LUA_TTABLE) {
 			lua_pushstring(L, "handler");
 			lua_gettable(L, -2);