From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Thu, 20 Feb 2020 15:56:54 +0000 (+0000)
Subject: [Minor] Protect lpeg code against empty texts
X-Git-Tag: 2.4~31
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9bdb819160c5e4f1626b3ddbc76391d8c29995fd;p=thirdparty%2Frspamd.git

[Minor] Protect lpeg code against empty texts
---

diff --git a/contrib/lua-lpeg/lptree.c b/contrib/lua-lpeg/lptree.c
index ffc03f7700..f4a58dbf04 100644
--- a/contrib/lua-lpeg/lptree.c
+++ b/contrib/lua-lpeg/lptree.c
@@ -1167,12 +1167,26 @@ static int lp_match (lua_State *L) {
   else if (lua_type (L, SUBJIDX) == LUA_TUSERDATA) {
   	struct rspamd_lua_text *t = lua_check_text (L, SUBJIDX);
   	if (!t) {
+#ifdef LPEG_LUD_WORKAROUND
+		lpeg_free_mem_low (capture);
+#endif
 		return luaL_error (L, "invalid argument (not a text)");
   	}
   	s = t->start;
   	l = t->len;
+
+  	if (s == NULL) {
+		lua_pushnil(L);
+#ifdef LPEG_LUD_WORKAROUND
+		lpeg_free_mem_low (capture);
+#endif
+		return 1;
+  	}
   }
   else {
+#ifdef LPEG_LUD_WORKAROUND
+  	lpeg_free_mem_low (capture);
+#endif
   	return luaL_error (L, "invalid argument");
   }
   size_t i = initposition(L, l);