From 80cb50dea482246656a49e54a915bdc343ffe897 Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@rspamd.com>
Date: Fri, 1 Nov 2024 09:38:11 +0000
Subject: [PATCH] [Fix] Fix memory leak in `lua_new_text` invocations

---
 src/lua/lua_common.h   |  5 ++---
 src/lua/lua_compress.c | 12 +++++++-----
 src/lua/lua_text.c     |  4 ++--
 src/lua/lua_util.c     | 11 +++++++++--
 4 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/lua/lua_common.h b/src/lua/lua_common.h
index 198735c66..1d39d0c52 100644
--- a/src/lua/lua_common.h
+++ b/src/lua/lua_common.h
@@ -94,8 +94,7 @@ static inline int lua_absindex(lua_State *L, int i)
 #define LUA_PUBLIC_FUNCTION_DEF(class, name) int lua_##class##_##name(lua_State *L)
 #define LUA_INTERFACE_DEF(class, name) \
 	{                                  \
-		#name, lua_##class##_##name    \
-	}
+		#name, lua_##class##_##name}
 
 extern const luaL_reg null_reg[];
 
@@ -281,7 +280,7 @@ struct rspamd_lua_text *lua_check_text_or_string(lua_State *L, int pos);
  * @return
  */
 struct rspamd_lua_text *lua_new_text(lua_State *L, const char *start,
-									 gsize len, gboolean own);
+									 gsize len, gboolean allocate_memory);
 /**
  * Create new text object from task pool if allocation is needed
  * @param task
diff --git a/src/lua/lua_compress.c b/src/lua/lua_compress.c
index 4a348404c..c82394ed6 100644
--- a/src/lua/lua_compress.c
+++ b/src/lua/lua_compress.c
@@ -1,11 +1,11 @@
-/*-
- * Copyright 2021 Vsevolod Stakhov
+/*
+ * Copyright 2024 Vsevolod Stakhov
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *   http://www.apache.org/licenses/LICENSE-2.0
+ *    http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -504,7 +504,8 @@ lua_zstd_compress_stream(lua_State *L)
 		return lua_zstd_push_error(L, err);
 	}
 
-	lua_new_text(L, onb.dst, onb.pos, TRUE);
+	t = lua_new_text(L, onb.dst, onb.pos, FALSE);
+	t->flags |= RSPAMD_TEXT_FLAG_OWN;
 
 	return 1;
 }
@@ -598,7 +599,8 @@ lua_zstd_decompress_stream(lua_State *L)
 		return lua_zstd_push_error(L, err);
 	}
 
-	lua_new_text(L, onb.dst, onb.pos, TRUE);
+	t = lua_new_text(L, onb.dst, onb.pos, FALSE);
+	t->flags |= RSPAMD_TEXT_FLAG_OWN;
 
 	return 1;
 }
diff --git a/src/lua/lua_text.c b/src/lua/lua_text.c
index 4478314f1..3342fc95c 100644
--- a/src/lua/lua_text.c
+++ b/src/lua/lua_text.c
@@ -312,14 +312,14 @@ lua_check_text_or_string(lua_State *L, int pos)
 }
 
 struct rspamd_lua_text *
-lua_new_text(lua_State *L, const char *start, gsize len, gboolean own)
+lua_new_text(lua_State *L, const char *start, gsize len, gboolean allocate_memory)
 {
 	struct rspamd_lua_text *t;
 
 	t = lua_newuserdata(L, sizeof(*t));
 	t->flags = 0;
 
-	if (own) {
+	if (allocate_memory) {
 		char *storage;
 
 		if (len > 0) {
diff --git a/src/lua/lua_util.c b/src/lua/lua_util.c
index 92f831f6f..251d1e1e7 100644
--- a/src/lua/lua_util.c
+++ b/src/lua/lua_util.c
@@ -1025,7 +1025,12 @@ lua_util_encode_base64(lua_State *L)
 		}
 
 		if (out != NULL) {
-			lua_new_text(L, out, outlen, TRUE);
+			/*
+			 * Manually set OWN flag, as `lua_new_text` will allocate another chunk of memory,
+			 * and we will have memory leak of the memory allocated by `rspamd_encode_base64_fold`
+			 */
+			t = lua_new_text(L, out, outlen, FALSE);
+			t->flags = RSPAMD_TEXT_FLAG_OWN;
 		}
 		else {
 			lua_pushnil(L);
@@ -1650,7 +1655,9 @@ lua_util_transliterate(lua_State *L)
 
 	gsize outlen;
 	char *transliterated = rspamd_utf8_transliterate(t->start, t->len, &outlen);
-	lua_new_text(L, transliterated, outlen, TRUE);
+
+	t = lua_new_text(L, transliterated, outlen, FALSE);
+	t->flags = RSPAMD_TEXT_FLAG_OWN;
 
 	return 1;
 }
-- 
2.39.5