Somewhat similar to  bug 487400 .

Jochen, I have no idea whom to assign this to. Could you please help to triage?

I can't repro on ToT (but on an older rev). Is it possible to make CF bisect this?

something writes a Smi(1) into the global proxy field of a native context.

This issue is a security regression. If you are not able to fix this quickly, please revert the change that introduced it.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

ClusterFuzz has detected this issue as fixed in range 405858:405980.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=4855910413631488

Fuzzer: inferno_webbot
Job Type: mac_asan_chrome
Platform Id: mac

Crash Type: UNKNOWN READ
Crash Address: 0x000100000038
Crash State:
  v8::Context::Global
  blink::toExecutionContext
  blink::ElementV8Internal::webkitMatchesSelectorMethodCallback
  
Recommended Security Severity: Medium

Regressed: https://cluster-fuzz.appspot.com/revisions?job=mac_asan_chrome&range=405727:405740
Fixed: https://cluster-fuzz.appspot.com/revisions?job=mac_asan_chrome&range=405858:405980

Minimized Testcase (0.09 Kb):
Download: https://cluster-fuzz.appspot.com/download/AMIfv94ApaQSkzC1pddyWmVnPyWuvhNQ0dTEAXuj7G2lu32NskT20jmOR_DFjb2oCVmkuZvT6Hni9gD1twvxRWZ8ncYDBP6UqVy_rPGz05g-wwyP6NqBzBR0D49NOFJFo4udW8bNDG1VFltrrbV8wQnBy2bU3-nIUA?testcase_id=4855910413631488
<script>
window.open("http://anel.com.tr");
window.location = "http://dev.com.br";</script>


See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

This bug has been closed for more than 14 weeks. Removing security view restrictions.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot