Predator and CL did not provide any possible suspects.
Using Code Search for the file, "low_cut_filter.cc" assigning to the concern owner.
Suspecting Commit#
https://chromium.googlesource.com/external/webrtc/trunk/webrtc.git/+/797d4cf2a8bf94549a93859e01bea3f04ba6a9f6

@aleloi -- Could you please look into the issue, kindly re-assign if this is not related to your changes.
Thank You.

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/b5c1607e9286581bb63c8225df75e47aff8eae96

commit b5c1607e9286581bb63c8225df75e47aff8eae96
Author: Alex Loiko <aleloi@webrtc.org>
Date: Tue Jul 18 12:23:08 2017

UBSan fuzzer bug in LowCutFilter::BiqueadFilter::Process

The variable 'tmp_int32' in LowCutFilter::BiqueadFilter::Process can
be negative. This replaces a left shift with multiplication.

Bug:  chromium:735593 ,  chromium:743330 
Change-Id: Idec7fbcc17495f7241eb4bea44920585740e3695
Reviewed-on: https://chromium-review.googlesource.com/575136
Commit-Queue: Alex Loiko <aleloi@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#19074}
[modify] https://crrev.com/b5c1607e9286581bb63c8225df75e47aff8eae96/webrtc/modules/audio_processing/low_cut_filter.cc

ClusterFuzz has detected this issue as fixed in range 488172:488220.

Detailed report: https://clusterfuzz.com/testcase?key=5037144400986112

Fuzzer: libFuzzer_audio_processing_fuzzer
Job Type: libfuzzer_chrome_ubsan
Platform Id: linux

Crash Type: Undefined-shift
Crash Address: 
Crash State:
  webrtc::LowCutFilter::BiquadFilter::Process
  webrtc::LowCutFilter::Process
  webrtc::AudioProcessingImpl::ProcessCaptureStreamLocked
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=481133:481204
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=488172:488220

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5037144400986112


See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.