LibJS: Avoid potential overflow in Array.prototype.toSpliced() #14466
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The implementation no longer matches the spec text, but I believe that's a bug anyway. No point in allowing array lengths up to 2^53 - 1 when the ArrayCreate AO rejects anything above 2^32 - 1.
IdanHo
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Jul 2, 2022
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| // FIXME: ArrayCreate throws for any length > 2^32 - 1, so there's no point in letting | ||
| // values up to 2^53 - 1 through (spec issue). This also prevents a potential | ||
| // overflow when casting from double to size_t, which is 32 bits on x86. | ||
| if (new_length_double > NumericLimits<u32>::max()) | ||
| return vm.throw_completion<TypeError>(global_object, ErrorType::ArrayMaxSize); |
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That's a good point, generally Array prototype methods allow up to MAX_ARRAY_LIKE_INDEX and not just 2^32 - 1, since they are supposed to be generic, so you can use them on other objects like strings that do not have this limitation, but these toX class of methods create arrays, so they do have to use the smaller maximum, which is the array maximum size.
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Filed tc39/proposal-change-array-by-copy#94 for this :)
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