From dbb0b68175613885654cc0541e19d0792169d52d Mon Sep 17 00:00:00 2001
From: Sam Atkins <atkinssj@serenityos.org>
Date: Thu, 31 Mar 2022 20:14:21 +0100
Subject: [PATCH] LibWeb: Disallow global CSS keywords in `@font-face`
 font-family

---
 Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
index 5595de37d51..53da4a29dd4 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
@@ -4412,6 +4412,11 @@ RefPtr<CSSRule> Parser::parse_font_face_rule(TokenStream<ComponentValue>& tokens
                     continue;
                 }
                 if (part.is(Token::Type::Ident)) {
+                    if (is_builtin(part.token().ident())) {
+                        dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face font-family format invalid; discarding.");
+                        had_syntax_error = true;
+                        break;
+                    }
                     auto value_id = value_id_from_string(part.token().ident());
                     if (is_generic_font_family(value_id)) {
                         dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face font-family format invalid; discarding.");