This is caused by uninitialized member field in AuthenticatorSupportedOptions (see https://chromium-review.googlesource.com/c/chromium/src/+/969799/13/device/fido/authenticator_supported_options.h#76).

https://chromium-review.googlesource.com/c/chromium/src/+/1115900 introduced a code path that depends on the value of the member field, thus leading to use of uninitialized memory. Find-It created a revert CL https://chromium-review.googlesource.com/c/chromium/src/+/1124020 that should be landed.

In addition, I created https://chromium-review.googlesource.com/c/chromium/src/+/1123828 to provide a default member initializer to ensure the memory is initialized.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f6b27bcd23ca81f7c1f5f8dc091cc78de21be428

commit f6b27bcd23ca81f7c1f5f8dc091cc78de21be428
Author: Sylvain Defresne <sdefresne@chromium.org>
Date: Tue Jul 03 16:43:15 2018

Ensure initialisation of AuthenticatorSupportedOptions' fields

Add a default member initialization for client_pin_availability_
to prevent use of un-initialized memory (found by MSan).

Bug:  859816 
Change-Id: I5ab81ee60a6aed657f44a8bee7d094dc14f030b9
Reviewed-on: https://chromium-review.googlesource.com/1123828
Reviewed-by: Jun Choi <hongjunchoi@chromium.org>
Commit-Queue: Jun Choi <hongjunchoi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572254}
[modify] https://crrev.com/f6b27bcd23ca81f7c1f5f8dc091cc78de21be428/device/fido/authenticator_supported_options.h