RUST-1240 Fix potential underflow in length counting #349
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isabelatkinson
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Mar 30, 2022
abr-egn
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RUST-1240
Because
length_remainingis ani32, thechecked_subcall would allow (invalid) negative values; this was caught by the fuzzer because this particular fuzz input happened to create a value negative enough that further subtraction elsewhere underflowed.As far as I can tell this doesn't have safety implications; the underlying buffer is accessed through a safe slice, so this would have caused a panic or at worst garbage parsed data.