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LibJS: Always taint parsing environment on call to eval()

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We had an edge case where calls to eval() left the environment untainted
*if* `eval` had also been declared as a local variable in the same
parsing context.

This broke the expected direct eval behavior when the variable `eval`
was still pointing at the global `eval` function.

This patch fixes the issue by simply always tainting the environment
when a call to something named `eval` is encountered. It doesn't seem
worth worrying about optimizing the case where someone is calling their
own function named `eval`..

Fixes 1 test-js test in bytecode mode. :^)
This commit is contained in:
Andreas Kling 2023-07-21 08:17:01 +02:00
parent c90bf22d29
commit 9054b1bc14
1 changed files with 2 additions and 13 deletions
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15
Userland/Libraries/LibJS/Parser.cpp
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@ -2230,19 +2230,8 @@ NonnullRefPtr<Expression const> Parser::parse_expression(int min_precedence, Ass
if (is<CallExpression>(*expression) && m_state.current_scope_pusher) {
auto& callee = static_ptr_cast<CallExpression const>(expression)->callee();
if (is<Identifier>(callee)) {
auto& identifier_instance = static_cast<Identifier const&>(callee);
if (identifier_instance.string() == "eval"sv) {
bool has_not_been_declared_as_variable = true;
for (auto scope = m_state.current_scope_pusher; scope; scope = scope->parent_scope()) {
if (scope->has_declaration(identifier_instance.string())) {
has_not_been_declared_as_variable = false;
break;
}
}
if (has_not_been_declared_as_variable)
m_state.current_scope_pusher->set_contains_direct_call_to_eval();
}
if (is<Identifier>(callee) && static_cast<Identifier const&>(callee).string() == "eval"sv) {
m_state.current_scope_pusher->set_contains_direct_call_to_eval();
}
}