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LibWeb: Fix CSS attribute and ID selector parsing

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There were several crashes here from out-of-bounds memory access.
This commit is contained in:
Sam Atkins 2021-07-07 20:47:09 +01:00 • committed by Andreas Kling
parent 78d191554a
commit e5ac5e1fab
1 changed files with 20 additions and 14 deletions
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34
Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
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@ -231,7 +231,6 @@ Optional<Selector> Parser::parse_single_selector(TokenStream<T>& tokens, bool is
auto parse_simple_selector = [&]() -> Optional<Selector::SimpleSelector> { auto parse_simple_selector = [&]() -> Optional<Selector::SimpleSelector> {
auto current_value = tokens.next_token(); auto current_value = tokens.next_token();
dbgln("parse_simple_selector, start token: {}", current_value.to_string());
if (check_for_eof_or_whitespace(current_value)) if (check_for_eof_or_whitespace(current_value))
return {}; return {};
@ -267,11 +266,19 @@ Optional<Selector> Parser::parse_single_selector(TokenStream<T>& tokens, bool is
type = Selector::SimpleSelector::Type::Class; type = Selector::SimpleSelector::Type::Class;
value = current_value.to_string(); value = current_value.to_string();
} else if (current_value.is(Token::Type::Delim) && ((Token)current_value).delim() == "*") { } else if (current_value.is(Token::Type::Delim) && current_value.token().delim() == "*") {
type = Selector::SimpleSelector::Type::Universal; type = Selector::SimpleSelector::Type::Universal;
} else { } else if (current_value.is(Token::Type::Ident)) {
type = Selector::SimpleSelector::Type::TagName; type = Selector::SimpleSelector::Type::TagName;
value = current_value.to_string().to_lowercase(); value = current_value.token().ident().to_lowercase_string();
} else if ((current_value.is(Token::Type::Delim) && current_value.token().delim() == ":")
|| (current_value.is_block() && current_value.block().is_square())) {
// FIXME: This is a temporary hack until we make the Selector::SimpleSelector::Type changes.
type = Selector::SimpleSelector::Type::Universal;
tokens.reconsume_current_input_token();
} else {
dbgln("Invalid simple selector!");
return {};
} }
Selector::SimpleSelector simple_selector; Selector::SimpleSelector simple_selector;
@ -302,13 +309,10 @@ Optional<Selector> Parser::parse_single_selector(TokenStream<T>& tokens, bool is
simple_selector.attribute_match_type = Selector::SimpleSelector::AttributeMatchType::HasAttribute; simple_selector.attribute_match_type = Selector::SimpleSelector::AttributeMatchType::HasAttribute;
simple_selector.attribute_name = attribute_part.token().ident(); simple_selector.attribute_name = attribute_part.token().ident();
size_t attribute_index = 0; if (attribute_parts.size() == 1)
while (attribute_parts.at(attribute_index).is(Token::Type::Whitespace)) { return simple_selector;
attribute_index++;
if (attribute_index >= attribute_parts.size())
return simple_selector;
}
size_t attribute_index = 1;
auto& delim_part = attribute_parts.at(attribute_index); auto& delim_part = attribute_parts.at(attribute_index);
if (!delim_part.is(Token::Type::Delim)) { if (!delim_part.is(Token::Type::Delim)) {
dbgln("Expected a delim for attribute comparison, got: '{}'", delim_part.to_string()); dbgln("Expected a delim for attribute comparison, got: '{}'", delim_part.to_string());
@ -326,7 +330,7 @@ Optional<Selector> Parser::parse_single_selector(TokenStream<T>& tokens, bool is
} }
auto& delim_second_part = attribute_parts.at(attribute_index); auto& delim_second_part = attribute_parts.at(attribute_index);
if (!(delim_part.is(Token::Type::Delim) && delim_part.token().delim() == "=")) { if (!(delim_second_part.is(Token::Type::Delim) && delim_second_part.token().delim() == "=")) {
dbgln("Expected a double delim for attribute comparison, got: '{}{}'", delim_part.to_string(), delim_second_part.to_string()); dbgln("Expected a double delim for attribute comparison, got: '{}{}'", delim_part.to_string(), delim_second_part.to_string());
return {}; return {};
} }
@ -450,6 +454,8 @@ Optional<Selector> Parser::parse_single_selector(TokenStream<T>& tokens, bool is
} }
} }
tokens.reconsume_current_input_token();
return simple_selector; return simple_selector;
}; };
@ -785,12 +791,12 @@ Optional<StyleDeclarationRule> Parser::consume_a_declaration(TokenStream<T>& tok
} }
} }
for (;;) { while (!declaration.m_values.is_empty()) {
auto maybe_whitespace = declaration.m_values.at(declaration.m_values.size() - 1); auto maybe_whitespace = declaration.m_values.last();
if (!(maybe_whitespace.is(Token::Type::Whitespace))) { if (!(maybe_whitespace.is(Token::Type::Whitespace))) {
break; break;
} }
declaration.m_values.remove(declaration.m_values.size() - 1); declaration.m_values.take_last();
} }
return declaration; return declaration;