Find it did not find provide any possible suspect.
Assigning to the concern owner from the regressed range -
https://chromium.googlesource.com/chromium/src/+log/b9014646db766be89300d38806c340e4b2772e7a..721ba2cac4a5b76803d9488a831a2bd44867ed81?pretty=fuller

Suspecting the Commit# 
https://chromium.googlesource.com/chromium/src/+/1deca3a90d6421a377d718d09479645af0d9fe53

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

I don't have free time to help. Reassigned.

https://pdfium-review.googlesource.com/c/3231/

The following revision refers to this bug:
  https://pdfium.googlesource.com/pdfium/+/96169fc007f271412ffa7bf2ebd3cf3fc04f71a5

commit 96169fc007f271412ffa7bf2ebd3cf3fc04f71a5
Author: Dan Sinclair <dsinclair@chromium.org>
Date: Mon Mar 27 18:45:54 2017

Verify available bits in bit stream

The methods to read n bits from the huffman stream are not correctly
checking that the bits are available. This means, we'll end up reading
0 bits due to the checks below and pretend like the read worked.

This Cl adds the check that we are not at the end of the bit buffer
before attempting the bit read.

Bug:  chromium:672176 
Change-Id: I206f2d54da31c344cf649ca024644d1cce762fe7
Reviewed-on: https://pdfium-review.googlesource.com/3231
Reviewed-by: Nicolás Peña <npm@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

[modify] https://crrev.com/96169fc007f271412ffa7bf2ebd3cf3fc04f71a5/core/fxcodec/jbig2/JBig2_BitStream.cpp

ClusterFuzz has detected this issue as fixed in range 459865:459906.

Detailed report: https://clusterfuzz.com/testcase?key=6157225234268160

Fuzzer: libfuzzer_pdf_codec_jbig2_fuzzer
Job Type: libfuzzer_chrome_msan
Platform Id: linux

Crash Type: Out-of-memory (exceeds 2048 MB)
Crash Address: 
Crash State:
  pdf_codec_jbig2_fuzzer
  
Sanitizer: memory (MSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_msan&range=421422:421468
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_msan&range=459865:459906

Reproducer Testcase: https://clusterfuzz.com/download/AMIfv943_LXSyuLQJd1sdLL24h8cu-GsoAA5bVZ2QIjIH2HGrLw6Mtl8PACaZeiW8mjGPV6SEyKso0CBOOp3E3kfpREKQfYBOJ-bz-PjdKv_45fdJ14yIOKBqvF5lejqmh2rSUEWcMZk6d3A3xezxE-ntbJreRO8wF0IDvd6-zOiykcGs9ocsNLS6Z066a3ryIHOHIOIP8XPy4T1BKpxdtuMbVggUMnfBsyRKoepqCBo9FIViy3BxrftS8hvwXJhCeEe8oczhJad4EH6Q79V3z-zMBeKY73NuUFHS6axW2gqFXCjKo21JOzW2bPD3jiugLnHObLDvYvhWBNbx0gB9b5O41oivOqG2bsXi_qXU4labYkyx35uZ2s?testcase_id=6157225234268160


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.

The following revision refers to this bug:
  https://pdfium.googlesource.com/pdfium/+/0eb74769c9efbcb94e57f160882ce3309684b2f9

commit 0eb74769c9efbcb94e57f160882ce3309684b2f9
Author: Dan Sinclair <dsinclair@chromium.org>
Date: Tue Mar 28 16:50:45 2017

Add JBig2_BitStream ReadNBits unittests

Add test for reading past end of buffer and successful read of bits.

Bug:  chromium:672176 
Change-Id: Ibe2d818185cdb2260011d3fc8cad94ebb16984b7
Reviewed-on: https://pdfium-review.googlesource.com/3233
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

[modify] https://crrev.com/0eb74769c9efbcb94e57f160882ce3309684b2f9/BUILD.gn
[add] https://crrev.com/0eb74769c9efbcb94e57f160882ce3309684b2f9/core/fxcodec/jbig2/JBig2_BitStream_unittest.cpp