LibCrypto: Avoid UB in BigFraction::to_byte_string for 0/x fractions

Author: https://github.com/DanShaders Commit: https://github.com/SerenityOS/serenity/commit/2a2e31f2ed Pull-request: https://github.com/SerenityOS/serenity/pull/23123 Reviewed-by: https://github.com/ADKaster ✅
2024-02-08 14:39:26 -05:00 · 2024-02-08 14:39:26 -05:00 · 2a2e31f2ed · 2024-07-17 06:09:44 +09:00
commit 2a2e31f2ed
parent bd26e5dce9
1 changed files with 1 additions and 1 deletions
--- a/Userland/Libraries/LibCrypto/BigFraction/BigFraction.cpp
+++ b/Userland/Libraries/LibCrypto/BigFraction/BigFraction.cpp
@ -213,7 +213,7 @@ ByteString BigFraction::to_byte_string(unsigned rounding_threshold) const
    auto const remove_trailing_zeros = [](StringView value) -> StringView {
        auto n = value.length();
        VERIFY(n > 0);
-        while (value.characters_without_null_termination()[n - 1] == '0')
+        while (n > 0 && value.characters_without_null_termination()[n - 1] == '0')
            --n;
        return { value.characters_without_null_termination(), n };
    };