cargo-fuzz is not happy with some of the code paths

[liuw]

The iced-x86 crate is used by Cloud Hypervisor to decode instructions.

I recently wrote this cloud-hypervisor/cloud-hypervisor#6895. It fuzzes a lot of the code paths in iced-x86.

cargo-fuzz reported a few leaks. Upon closer inspection they are both from iced-x86. I disabled the two features for now to placate libfuzzer.

Looking at the output from the fuzzer, it is likely complaining these two places (v1.21.0).

iced/src/rust/iced-x86/src/formatter/fast/fmt_tbl.rs

Line 72 in c50f29b

let len_data = Box::leak(Box::new(new_vec)).as_ptr();

iced/src/rust/iced-x86/src/decoder/table_de/mod.rs

Line 37 in c50f29b

(decode, Box::into_raw(Box::new(handler)) as *const OpCodeHandler)

I don't think these are accidental leaks. Not sure what's the best way to fix them.

[wtfsck]

can you test against master

[liuw]

I did take a brief look at the difference between master and v1.21.0. I see that the formatter has been changed, but the table_de module code which calls Box::into_raw is still there. I expect libfuzzer will continue to complain about the latter.

I can try finding some time to reproduce this on master. That's going to take a while though.

[wtfsck]

There's at least one pr that possibly fixed this #528

[liuw]

Good to know. I will circle back when I try out master.

[liuw]

Both leaks are gone in the master branch. Closing this.