Predator and CL could not provide any possible suspects.
Using the code search for the file, “xfa_codec_fuzzer.h” assigning to concern owner from GIT blame.
Suspecting Commit#
https://pdfium.googlesource.com/pdfium.git/+/704cf8361659c4719d1294048a0e37991fa41748

@rharrison -- Could you please look into this issue, kindly reassign if it has nothing to do with your changes.
Thank You.

The following revision refers to this bug:
  https://pdfium.googlesource.com/pdfium/+/1fc3c3b309d96b4e4f4c6d8b270a4e72710ca4a1

commit 1fc3c3b309d96b4e4f4c6d8b270a4e72710ca4a1
Author: Ryan Harrison <rharrison@chromium.org>
Date: Mon Oct 30 14:06:12 2017

Fix overflow in image size check

BUG= chromium:779342 

Change-Id: I2a087a08fe87594eb73d9d955955be0e66e5cdc2
Reviewed-on: https://pdfium-review.googlesource.com/17030
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

[modify] https://crrev.com/1fc3c3b309d96b4e4f4c6d8b270a4e72710ca4a1/testing/libfuzzer/xfa_codec_fuzzer.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e7a3f7c4e9adced8f6f82e4db170db84996767c5

commit e7a3f7c4e9adced8f6f82e4db170db84996767c5
Author: pdfium-deps-roller@chromium.org <pdfium-deps-roller@chromium.org>
Date: Mon Oct 30 16:48:34 2017

Roll src/third_party/pdfium/ 7170226d2..1fc3c3b30 (1 commit)

https://pdfium.googlesource.com/pdfium.git/+log/7170226d2020..1fc3c3b309d9

$ git log 7170226d2..1fc3c3b30 --date=short --no-merges --format='%ad %ae %s'
2017-10-30 rharrison Fix overflow in image size check

Created with:
  roll-dep src/third_party/pdfium
BUG= 779342 


Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls


TBR=dsinclair@chromium.org

Change-Id: Ib002c903b923ca2efe472c96c9da0a3e4a7a9d74
Reviewed-on: https://chromium-review.googlesource.com/743711
Reviewed-by: <pdfium-deps-roller@chromium.org>
Commit-Queue: <pdfium-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512517}
[modify] https://crrev.com/e7a3f7c4e9adced8f6f82e4db170db84996767c5/DEPS

ClusterFuzz has detected this issue as fixed in range 512499:512517.

Detailed report: https://clusterfuzz.com/testcase?key=5249135879127040

Fuzzer: libFuzzer_pdf_codec_png_fuzzer
Job Type: libfuzzer_chrome_ubsan
Platform Id: linux

Crash Type: Integer-overflow
Crash Address: 
Crash State:
  XFACodecFuzzer::Fuzz
  _start
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=512223:512260
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=512499:512517

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5249135879127040

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

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

ClusterFuzz testcase 5249135879127040 is verified as fixed, so closing issue as verified.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.