#459 Signed Integer Overflow - 65657174

[Google-Autofuzz]

Hello flac team,

As part of our fuzzing efforts at Google, we have identified an issue affecting
flac (tested with revision * master f7cd466c24fb5d1966943f3ea36a1f4a37858597).

To reproduce, we are attaching a Dockerfile which compiles the project with
LLVM, taking advantage of the sanitizers that it offers. More information about
how to use the attached Dockerfile can be found here:
https://docs.docker.com/engine/reference/builder/

TL;DR instructions:
mkdir project
cp Dockerfile /path/to/project
docker build --no-cache /path/to/project
docker run -it image_id_from_docker_build

From another terminal, outside the container:
docker cp /path/to/attached/reproducer running_container_hostname:/fuzzing/reproducer
(reference: https://docs.docker.com/engine/reference/commandline/cp/)

And, back inside the container:
/fuzzing/repro.sh /fuzzing/reproducer

Alternatively, and depending on the bug, you could use gcc, valgrind or other
instrumentation tools to aid in the investigation. The sanitizer error that we
encountered is here:

sample rate : 44100 Hz
channels : 2
bits per sample: 16
total samples : 3261048
fixed.c:378:27: runtime error: signed integer overflow: -415664578 + -2084338901 cannot be represented in type 'int'
SUMMARY: AddressSanitizer: undefined-behavior fixed.c:378:27 in

We will gladly work with you so you can successfully confirm and reproduce this
issue. Do let us know if you have any feedback surrounding the documentation.

Once you have reproduced the issue, we'd appreciate to learn your expected
timeline for an update to be released. With any fix, please attribute the report
to "Google Autofuzz project".

We are also pleased to inform you that your project is eligible for inclusion to
the OSS-Fuzz project, which can provide additional continuous fuzzing, and
encourage you to investigate integration options.

Don't hesitate to let us know if you have any questions!

Google AutoFuzz Team

[Erik]

This one is like #466, undefined behavior in the audio path.

I highly recommend only fuzzing FLAC with the address sanitizer enabled and the undefined behavior sanitizer disabled.