Hi haraken, this looks like it's in the guts of Oilpan. Do you mind taking a look / retriaging? The blame list from ClusterFuzz isn't very useful. Thanks!

inferno@: https://cluster-fuzz.appspot.com/v2/testcase-detail/5211998389534720 is saying "possibly invalid vptr", but what does it mean? It looks like we're just casting a GCed object to DOMException.

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

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ClusterFuzz has detected this issue as fixed in range 434636:434661.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5211998389534720

Fuzzer: therealholden_worker
Job Type: linux_ubsan_vptr_chrome
Platform Id: linux

Crash Type: Bad-cast
Crash Address: 0x01f2e8c6d860
Crash State:
  Bad-cast to blink::DOMExceptionblink::GarbageCollectedFinalized<blink::DOMException>::finalizeGarbageCollectedObject
  blink::NormalPage::sweep
  blink::BaseArena::sweepUnsweptPage
  
Recommended Security Severity: High

Regressed: https://cluster-fuzz.appspot.com/revisions?job=linux_ubsan_vptr_chrome&range=434178:434216
Fixed: https://cluster-fuzz.appspot.com/revisions?job=linux_ubsan_vptr_chrome&range=434636:434661

Unminimized Testcase: https://cluster-fuzz.appspot.com/download/AMIfv946K9jW7INLma_TsU3Ijs5ikrdbmMGaiRZbo3JbgsJkTEyH_fo5hMxLRSN6hlj1-7b1TblVhm98bTr-3xnxAPBf36A4SAmDkkddoBQKjsqvHIkL46fWxUa7dN1H0sr07OY_N9x3mgijqqyad8Q-xMR-sRTMaA?testcase_id=5211998389534720


Additional requirements: Requires HTTP

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.

ClusterFuzz testcase is verified as fixed, closing issue.

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

The panel that declined to reward in this case, as we didn't take a fix as a result of this report. Seems like a UAF, which ubsan vptr doesn't handle too well.

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