[Minor] Add protection against infinite recursion

diff --git a/src/lua/lua_cryptobox.c b/src/lua/lua_cryptobox.c
index 821baae47f99dab090eeafa9384425da83fce05a..0fa9e23c1592523ecdcb65a09f0022bc9039696e 100644 (file)
--- a/src/lua/lua_cryptobox.c
+++ b/src/lua/lua_cryptobox.c
@@ -1412,13 +1412,20 @@ lua_cryptobox_hash_copy(const struct rspamd_lua_cryptobox_hash *orig)
        return nhash;
 }
 
+#define MAX_HASH_UPDATE_REC 16
+
 static void
-lua_cryptobox_update_pos(lua_State *L, struct rspamd_lua_cryptobox_hash *h, int pos)
+lua_cryptobox_update_pos(lua_State *L, struct rspamd_lua_cryptobox_hash *h, int pos, int rec)
 {
        const char *data;
        struct rspamd_lua_text *t;
        gsize len;
 
+       if (rec > MAX_HASH_UPDATE_REC) {
+               /* Max recursion is reached, do nothing */
+               return;
+       }
+
        /* Inverse pos if it is relative to the top of the stack */
        if (pos < 0) {
                pos = lua_gettop(L) + pos + 1;
@@ -1462,7 +1469,7 @@ lua_cryptobox_update_pos(lua_State *L, struct rspamd_lua_cryptobox_hash *h, int
 
                for (gsize i = 1; i <= alen; i++) {
                        lua_rawgeti(L, pos, i);
-                       lua_cryptobox_update_pos(L, h, -1); /* Recurse */
+                       lua_cryptobox_update_pos(L, h, -1, rec + 1); /* Recurse */
                        lua_pop(L, 1);
                }
 
@@ -1475,14 +1482,14 @@ lua_cryptobox_update_pos(lua_State *L, struct rspamd_lua_cryptobox_hash *h, int
                        struct lua_hash_elt he;
                        /* Hash key */
                        lua_pushvalue(L, -2);
-                       lua_cryptobox_update_pos(L, key_h, -1);
+                       lua_cryptobox_update_pos(L, key_h, -1, rec + 1);
                        lua_pop(L, 1);
                        lua_cryptobox_hash_finish(key_h);
                        memcpy(he.key_hash, key_h->out, sizeof(he.key_hash));
                        REF_RELEASE(key_h);
 
                        /* Hash value */
-                       lua_cryptobox_update_pos(L, value_h, -1);
+                       lua_cryptobox_update_pos(L, value_h, -1, rec + 1);
                        lua_pop(L, 1);
                        lua_cryptobox_hash_finish(value_h);
                        memcpy(he.value_hash, value_h->out, sizeof(he.value_hash));
@@ -1536,7 +1543,7 @@ lua_cryptobox_hash_update(lua_State *L)
                return luaL_error(L, "invalid arguments or hash is already finalized");
        }
 
-       lua_cryptobox_update_pos(L, h, 2);
+       lua_cryptobox_update_pos(L, h, 2, 0);
 
        ph = lua_newuserdata(L, sizeof(void *));
        *ph = h;