It's called from WebAXObject::UpdateLayoutAndCheckValidity(). dmazzoni@ can you take a look?

I think the priority of this might be lower since it relies on a test_runner API: accessibilityController.addNotificationListener.

Here's the smallest repro I could create - make sure the relative path to js-test.js is updated.

<script src="../resources/js-test.js"></script>
<button style="height: 600px;">
<script>
window.jsTestIsAsync = true;
    window.scrollTo(0, 223);
    shouldBe("window.pageYOffset", "0");
    accessibilityController.addNotificationListener(function (target, notification) {
        shouldBe("window.pageYOffset", "500");
    });
</script>

The crash is happening when AccessibilityController::NotificationReceived calls WebAXObject::UpdateLayoutAndCheckValidity(), which calls FrameView::UpdateLifecycleToCompositingCleanPlusScrolling(), and the crash is happening here:

  ForAllNonThrottledFrameViews([](FrameView& frame_view) {
    frame_view.PerformScrollAnchoringAdjustments();
  });

AccessibilityController::NotificationReceived is happening inside of a timer callback, so it should be a safe place to update layout.

I think someone who understands scroll anchoring should take a look.

ClusterFuzz has detected this issue as fixed in range 471033:471049.

Detailed report: https://clusterfuzz.com/testcase?key=4635463068680192

Fuzzer: ochang_domfuzzer
Job Type: linux_asan_content_shell_drt
Platform Id: linux

Crash Type: Use-after-poison READ 8
Crash Address: 0x7ecc229aab10
Crash State:
  void blink::FrameView::forAllNonThrottledFrameViews<blink::FrameView::updateLife
  blink::FrameView::updateLifecyclePhasesInternal
  blink::WebAXObject::updateLayoutAndCheckValidity
  
Sanitizer: address (ASAN)

Recommended Security Severity: High

Regressed: https://clusterfuzz.com/revisions?job=linux_asan_content_shell_drt&range=434178:434255
Fixed: https://clusterfuzz.com/revisions?job=linux_asan_content_shell_drt&range=471033:471049

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4635463068680192


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 4635463068680192 is verified as fixed, so closing issue.

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

Your change meets the bar and is auto-approved for M59. Please go ahead and merge the CL to branch 3071 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), gkihumba@(ChromeOS), Abdul Syed@(Desktop)

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

Please merge your change to M59 branch 3071 before 4:00 PM PT tomorrow, Tuesday (05/16 )so we can pick it for this week beta release. Thank you.

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

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

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

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

+awhalley

awhalley@, since this is security-related, can you confirm if anything needs to be merged here for M59?

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