Add memory bounds to fuzz harnesses, add test for a new crasher #181
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With the changes we've made recently, the fuzzer has been running out of memory by discovering very large padding 😂 In this commit, I attempted to fix these fuzzing failures by using the `strftime::io` and `strftime::fmt` variants. In `strftime::fmt`, the fuzzer immediately found a crash. If a multibyte UTF-8 sequence appears immediately following a `%` spec begin marker, the loop to pluck out padding consumes one element from the cursor and then breaks. This leads to pushing a partial UTF-8 character into the `fmt::Write` instance, which causes a panic in the underlying `String` because the string's contents is now malformed UTF-8. Add a test and break with `None` if encountering a non-ASCII byte while processing the spec. I've also cleaned up the fuzz targets so they build without warnings.
x-hgg-x
approved these changes
Mar 23, 2025
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I added more commits to fix another issue found by the fuzzer. |
lopopolo
commented
Mar 23, 2025
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With the changes we've made recently, the fuzzer has been running out of memory by discovering very large padding 😂
In this commit, I attempted to fix these fuzzing failures by using the
strftime::ioandstrftime::fmtvariants. Instrftime::fmt, the fuzzer immediately found a crash.If a multibyte UTF-8 sequence appears immediately following a
%spec begin marker, the loop to pluck out padding consumes one element from the cursor and then breaks. This leads to pushing a partial UTF-8 character into thefmt::Writeinstance, which causes a panic in the underlyingStringbecause the string's contents is now malformed UTF-8.Add a test and break with
Noneif encountering a non-ASCII byte while processing the spec.I've also cleaned up the fuzz targets so they build without warnings.