Unable to find actual suspect through code search and also observing no related changes under regression range, hence adding appropriate label and requesting someone from blink team to look in to this issue.

Thanks!

Hello, this is due to a recent change to the CFI build that enabled cfi-icall checking. This code in libwebp was not hit by the regular unit tests but is hit by ClusterFuzz. I'm preparing a fix now.

https://chromium-review.googlesource.com/c/webm/libwebp/+/991091

The following revision refers to this bug:
  https://chromium.googlesource.com/webm/libwebp/+/978eec2507e3b5110bd1d2a408fa27a8f7e702cf

commit 978eec2507e3b5110bd1d2a408fa27a8f7e702cf
Author: Vlad Tsyrklevich <vtsyrklevich@chromium.org>
Date: Mon Apr 02 23:04:47 2018

[CFI] Remove function pointer casts

Control Flow Integrity [1] indirect call checking verifies that function
pointers only call valid functions with a matching type signature. This
change eliminates function pointer casts that were causing cfi-icall
failures.

[1] https://www.chromium.org/developers/testing/control-flow-integrity

BUG= chromium:827826 

Change-Id: I5db021d06390a6cefd670fdd2f0d34c9e530465e

[modify] https://crrev.com/978eec2507e3b5110bd1d2a408fa27a8f7e702cf/src/enc/alpha_enc.c
[modify] https://crrev.com/978eec2507e3b5110bd1d2a408fa27a8f7e702cf/src/enc/vp8l_enc.c
[modify] https://crrev.com/978eec2507e3b5110bd1d2a408fa27a8f7e702cf/src/enc/analysis_enc.c
[modify] https://crrev.com/978eec2507e3b5110bd1d2a408fa27a8f7e702cf/src/dec/frame_dec.c

The following revision refers to this bug:
  https://chromium.googlesource.com/webm/libwebp/+/38410c082fe2879f02cb60840b5fe8347c78e46b

commit 38410c082fe2879f02cb60840b5fe8347c78e46b
Author: Vlad Tsyrklevich <vtsyrklevich@chromium.org>
Date: Mon Apr 02 23:57:14 2018

[CFI] Remove function pointer casts

Control Flow Integrity [1] indirect call checking verifies that function
pointers only call valid functions with a matching type signature. This
change eliminates function pointer casts that were causing cfi-icall
failures.

[1] https://www.chromium.org/developers/testing/control-flow-integrity

BUG= chromium:827826 

Change-Id: I5db021d06390a6cefd670fdd2f0d34c9e530465e
(cherry picked from commit 978eec2507e3b5110bd1d2a408fa27a8f7e702cf)

[modify] https://crrev.com/38410c082fe2879f02cb60840b5fe8347c78e46b/src/enc/alpha_enc.c
[modify] https://crrev.com/38410c082fe2879f02cb60840b5fe8347c78e46b/src/enc/vp8l_enc.c
[modify] https://crrev.com/38410c082fe2879f02cb60840b5fe8347c78e46b/src/enc/analysis_enc.c
[modify] https://crrev.com/38410c082fe2879f02cb60840b5fe8347c78e46b/src/dec/frame_dec.c

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9a2e56d309666af45a844d9b6eb7465729c6ab41

commit 9a2e56d309666af45a844d9b6eb7465729c6ab41
Author: Vlad Tsyrklevich <vtsyrklevich@chromium.org>
Date: Wed Apr 04 22:53:09 2018

libwebp: cherry-pick upstream commit 978eec25

BUG= 827826 

Change-Id: I6b91c4a9691f19df11f39a0799df5d5a4703681f
Reviewed-on: https://chromium-review.googlesource.com/996251
Reviewed-by: James Zern <jzern@google.com>
Commit-Queue: Peter Collingbourne <pcc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548226}
[modify] https://crrev.com/9a2e56d309666af45a844d9b6eb7465729c6ab41/third_party/libwebp/README.chromium
[modify] https://crrev.com/9a2e56d309666af45a844d9b6eb7465729c6ab41/third_party/libwebp/src/dec/frame_dec.c
[modify] https://crrev.com/9a2e56d309666af45a844d9b6eb7465729c6ab41/third_party/libwebp/src/enc/alpha_enc.c
[modify] https://crrev.com/9a2e56d309666af45a844d9b6eb7465729c6ab41/third_party/libwebp/src/enc/analysis_enc.c
[modify] https://crrev.com/9a2e56d309666af45a844d9b6eb7465729c6ab41/third_party/libwebp/src/enc/vp8l_enc.c

ClusterFuzz has detected this issue as fixed in range 547798:549174.

Detailed report: https://clusterfuzz.com/testcase?key=4875000893669376

Fuzzer: inferno_webbot
Job Type: linux_cfi_chrome
Platform Id: linux

Crash Type: UNKNOWN
Crash Address: 
Crash State:
  Execute$1b5b4d74f2b6cc593f836dd5164b9587.cfi
  VP8EncAnalyze.cfi
  WebPEncode.cfi
  
Sanitizer: cfi (CFI)

Regressed: https://clusterfuzz.com/revisions?job=linux_cfi_chrome&range=546919:546953
Fixed: https://clusterfuzz.com/revisions?job=linux_cfi_chrome&range=547798:549174

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4875000893669376

See https://github.com/google/clusterfuzz-tools 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 4875000893669376 is verified as fixed, so closing issue as verified.

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