commit d579e6bc7b28c724969c91e64052d8d4230b4aac
author Victor Boivie <boivie@webrtc.org> Wed Jun 09 07:24:26 2021
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Jun 16 13:02:32 2021
tree d32d55973c0cdcace0839a49bd4564d673f06ae5
parent 72b79986a57602515598056315a51c81f4cb8e56

dcsctp: Do explicit bounds checking in bounded IO

The previous approach was that the caller was responsible for ensuring
that any buffer passed in to the Bounded IO wrappers, and that any
offset from where sub-readers were created were valid. The called would
always do a validation of the data and return proper error messages
if they were not.

This didn't pan out. https://crbug.com/1216758 found an overflow that
fooled the validation logic and the fuzzer could read out-of-bounds,
although it would always crash in that particular case.

There was already bounds checking, but under DCHECKs. This CL changes
that so that any bounds checking is done with CHECKS, as would've been
done in Rust. It's better to crash than to read arbitrary memory.

Bug: chromium:1216758
Change-Id: I89b52f0758495b5fe46f926c142870a263b96314
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/221743
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34303}