Predator did not provide any possible suspects.
Assigning to concern owner from CL --
https://chromium.googlesource.com/chromium/src/+log/34d219ed15d7efa1e01cf832de018ff7f28eb995..3ec03002a6414356338782bb9ed7239d4b0c16d9?pretty=fuller

Suspecting Commit#
https://chromium.googlesource.com/chromium/src/+/458f112fc74b085dc972e35bed33665e465a8ba3

From the above commit assigning to concern owner--
@rharrison -- Could you please look into the issue, kindly re-assign if this is not related to your changes.
Thank You.

Fixed by https://pdfium-review.googlesource.com/c/9630

The following revision refers to this bug:
  https://pdfium.googlesource.com/pdfium/+/b73680c6b57d3848de6e1a2355b4650601031e12

commit b73680c6b57d3848de6e1a2355b4650601031e12
Author: Ryan Harrison <rharrison@chromium.org>
Date: Mon Jul 31 18:36:00 2017

Remove null derefence case caught by fuzzers

This change also removes some variable shadowing that was going on
here.

BUG= chromium:750013 

Change-Id: I7314166af3ecd55ea5e1105afbe171443b1b22ae
Reviewed-on: https://pdfium-review.googlesource.com/9630
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

[modify] https://crrev.com/b73680c6b57d3848de6e1a2355b4650601031e12/xfa/fxfa/fm2js/cxfa_fmparser.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/465d8c7e2f9ef26784e50e8360f80340fec7ed05

commit 465d8c7e2f9ef26784e50e8360f80340fec7ed05
Author: pdfium-deps-roller@chromium.org <pdfium-deps-roller@chromium.org>
Date: Tue Aug 01 06:41:40 2017

Roll src/third_party/pdfium/ f0e9c849a..ab3909796 (5 commits)

https://pdfium.googlesource.com/pdfium.git/+log/f0e9c849a3fd..ab3909796cf2

$ git log f0e9c849a..ab3909796 --date=short --no-merges --format='%ad %ae %s'
2017-07-28 drgage Add FORM_ReplaceSelection() and embedder tests.
2017-07-31 hnakashima Initialize CPDF_PathObject members on constructor.
2017-07-31 rharrison Remove null derefence case caught by fuzzers
2017-07-31 rharrison Fix bad change when converting Mid to Left/Right
2017-07-31 rharrison More fixes for coverage_report.py

Created with:
  roll-dep src/third_party/pdfium
BUG= 59266 , 750013 , 750568 


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: I014ffe18675c95a6778bd99e50f317801a45f0fd
Reviewed-on: https://chromium-review.googlesource.com/595122
Reviewed-by: <pdfium-deps-roller@chromium.org>
Commit-Queue: <pdfium-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490888}
[modify] https://crrev.com/465d8c7e2f9ef26784e50e8360f80340fec7ed05/DEPS

ClusterFuzz has detected this issue as fixed in range 490884:490938.

Detailed report: https://clusterfuzz.com/testcase?key=5568761024479232

Fuzzer: afl_pdf_fm2js_fuzzer
Job Type: afl_chrome_asan
Platform Id: linux

Crash Type: Null-dereference READ
Crash Address: 0x000000000010
Crash State:
  CXFA_FMParser::ParsePostExpression
  CXFA_FMParser::ParsePrimaryExpression
  CXFA_FMParser::ParseUnaryExpression
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=afl_chrome_asan&range=490107:490254
Fixed: https://clusterfuzz.com/revisions?job=afl_chrome_asan&range=490884:490938

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5568761024479232


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.

ClusterFuzz testcase 5568761024479232 is verified as fixed, so closing issue as verified.

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