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AK+Everywhere: Fix data corruption due to code-point-to-char conversion

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In particular, StringView::contains(char) is often used with a u32
code point. When this is done, the compiler will for some reason allow
data corruption to occur silently.

In fact, this is one of two reasons for the following OSS Fuzz issue:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=49184
This is probably a very old bug.

In the particular case of URLParser, AK::is_url_code_point got confused:
    return /* ... */ || "!$&'()*+,-./:;=?@_~"sv.contains(code_point);
If code_point is a large code point that happens to have the correct
lower bytes, AK::is_url_code_point is then convinced that the given
code point is okay, even if it is actually problematic.

This commit fixes *only* the silent data corruption due to the erroneous
conversion, and does not fully resolve OSS-Fuzz#49184.
This commit is contained in:
Ben Wiederhake 2022-09-12 16:31:16 +02:00 • committed by Andrew Kaster
parent f07e0180d6
commit 3aeb57ed09
7 changed files with 29 additions and 13 deletions
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2
Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Headers.cpp
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@ -402,7 +402,7 @@ bool is_cors_safelisted_request_header(Header const& header)
else if (name.is_one_of_ignoring_case("accept-language"sv, "content-language"sv)) {
// If value contains a byte that is not in the range 0x30 (0) to 0x39 (9), inclusive, is not in the range 0x41 (A) to 0x5A (Z), inclusive, is not in the range 0x61 (a) to 0x7A (z), inclusive, and is not 0x20 (SP), 0x2A (*), 0x2C (,), 0x2D (-), 0x2E (.), 0x3B (;), or 0x3D (=), then return false.
if (any_of(value.span(), [](auto byte) {
return !(is_ascii_digit(byte) || is_ascii_alpha(byte) || " *,-.;="sv.contains(byte));
return !(is_ascii_digit(byte) || is_ascii_alpha(byte) || " *,-.;="sv.contains(static_cast<char>(byte)));
}))
return false;
}