When a HEARTBEAT is sent out, the current timestamp is stored in the
parameter that will be returned by the HEARTBEAT-ACK. If the timestamp
from the HEARTBEAT-ACK would be from the future (either by jumping
clocks, bit errors, exploiting peer or a fuzzer), the measured RTT would
become really large, and when it was calculated, it would result in an
integer overflow; a wrapping subtraction.
This isn't a problem, as RetransmissionTimeout::ObserveRTT method would
discard measurements that were negative or too large, but it would
trigger an UBSAN violation.
Adding an additional check so that the subtraction doesn't ever wrap.
Bug: chromium:1252515
Change-Id: I1f97b1e773a4639b8193a528716ebd6a27fcb740
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/232904
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35095}
f75f9c2b29