Predator and CL could not provide any possible suspects.

Using Code Search for the file, "threading.c" suspecting the below Cl might have caused this issue

Suspect CL: https://chromium.googlesource.com/webm/libvpx.git/+/45cf384738ad261de7d00769c19b9b2842af06a7

jianj@ -- Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Thanks!

ClusterFuzz testcase 5643071879118848 appears to be flaky, updating reproducibility label.

It could be fixed by this CL:

https://chromium-review.googlesource.com/c/webm/libvpx/+/1165791

I tried the fuzzer with this CL and it was fixed. 

I'm still working on that.

The following revision refers to this bug:
  https://chromium.googlesource.com/webm/libvpx/+/ca9ab3fc46b2d3d839ff1e09660e83f146dd9a0b

commit ca9ab3fc46b2d3d839ff1e09660e83f146dd9a0b
Author: Jerome Jiang <jianj@google.com>
Date: Wed Aug 22 18:03:32 2018

Revert "vp8: Fix memory address overflow in decoder."

This reverts commit 45cf384738ad261de7d00769c19b9b2842af06a7.

BUG= 875626 , 875680 ,webm:1496

Change-Id: I78037b5e57dbf6cfe326b29beaad1128868f09f2

[modify] https://crrev.com/ca9ab3fc46b2d3d839ff1e09660e83f146dd9a0b/vp8/decoder/threading.c

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8abf422373a5f872de1d91e16102ed908049fb5b

commit 8abf422373a5f872de1d91e16102ed908049fb5b
Author: Jerome Jiang <jianj@google.com>
Date: Wed Aug 22 23:14:23 2018

Roll src/third_party/libvpx/source/libvpx/ 6c62530c6..dbcb89be2 (28 commits)

https://chromium.googlesource.com/webm/libvpx.git/+log/6c62530c666f..dbcb89be244e

$ git log 6c62530c6..dbcb89be2 --date=short --no-merges --format='%ad %ae %s'
2018-08-22 jianj Revert "vp8: Fix memory address overflow in decoder."
2018-08-22 jingning Set refresh_frame_context flag off in show_existing_frame mode
2018-08-21 jingning Drop empty line in vp9_get_compressed_data()
2018-08-21 jingning Allow codec to skip temporal filter for intermediate ARFs
2018-08-21 jingning Control reference frame refresh flags for USE_BUF_FRAME
2018-08-21 jingning Safely swap the show frame buffer pointer in show_existing mode
2018-08-21 jingning Skip loop filter operation in show_existing_frame mode
2018-08-21 jingning Point show frame buffer towards existing frame buffer
2018-08-21 jingning Skip frame encoding when show_existing_frame is on
2018-08-21 jingning Add USE_BUF_FRAME enum to FRAME_UPDATE_TYPE
2018-08-20 jingning Unify set_arf_sign_bias function
2018-08-20 jingning Remove unneeded frame_till_gf_update_due assignment
2018-08-20 jingning Add multi_layer_arf flag
2018-08-20 jingning Add a comment in init_gop_frames()
2018-06-12 supradeep.tr Loopfilter MultiThread Optimization
2018-08-17 jingning Skip frame bit-stream writing for show-existing frame
2018-08-17 jingning Support code show_existing_frame in bit-stream header
2018-08-17 jingning Refactor init_gop_frame()
2018-08-17 jingning Clean up var define in apply_temporal_filter()
2018-08-17 jingning Add inline to mod_index()
(...)

Created with:
  roll-dep src/third_party/libvpx/source/libvpx
R=johannkoenig@google.com
BUG= 875626 , 875680 

Change-Id: I4d395733d13462e248119791f9483396c0614f5b
Reviewed-on: https://chromium-review.googlesource.com/1185797
Reviewed-by: Johann Koenig <johannkoenig@google.com>
Commit-Queue: Jerome Jiang <jianj@google.com>
Cr-Commit-Position: refs/heads/master@{#585297}
[modify] https://crrev.com/8abf422373a5f872de1d91e16102ed908049fb5b/DEPS
[modify] https://crrev.com/8abf422373a5f872de1d91e16102ed908049fb5b/third_party/libvpx/README.chromium
[modify] https://crrev.com/8abf422373a5f872de1d91e16102ed908049fb5b/third_party/libvpx/libvpx_srcs.gni
[modify] https://crrev.com/8abf422373a5f872de1d91e16102ed908049fb5b/third_party/libvpx/source/config/vpx_version.h

The CL causing this has been reverted.

The following revision refers to this bug:
  https://chromium.googlesource.com/webm/libvpx/+/f3a027a46de103c97f9f413fea003dc3d97e2cfc

commit f3a027a46de103c97f9f413fea003dc3d97e2cfc
Author: Jerome Jiang <jianj@google.com>
Date: Wed Oct 31 18:42:28 2018

vp8: fix to address overflow in decoder.

Can't call internal error from the decoder thread.

Add vpx_internal_error_info to MACROBLOCKD. When corrupted frame
detected, the decoder thread returns to its own context and signal
completion of decoding for current frame.

The main decoding thread will detect error too and return error code to
decoding API call.

Each thread will signal end of decoding of the frame. Main thread waits
for the signal of all other threads to start decoding next frame.

BUG= 875626 ,webm:1496
Change-Id: Icd05fbc558893a4e7d8532c1e7177e7550283a64

[modify] https://crrev.com/f3a027a46de103c97f9f413fea003dc3d97e2cfc/vp8/decoder/threading.c
[modify] https://crrev.com/f3a027a46de103c97f9f413fea003dc3d97e2cfc/vp8/common/blockd.h
[modify] https://crrev.com/f3a027a46de103c97f9f413fea003dc3d97e2cfc/vp8/decoder/decoderthreading.h
[modify] https://crrev.com/f3a027a46de103c97f9f413fea003dc3d97e2cfc/vp8/decoder/onyxd_if.c
[modify] https://crrev.com/f3a027a46de103c97f9f413fea003dc3d97e2cfc/vp8/decoder/decodeframe.c