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

If this doesn't affect a release branch, or has not been properly classified for severity, please update the Security_Impact or Security_Severity labels, and remove the ReleaseBlock label. To disable this altogether, apply ReleaseBlock-NA.

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

Automatically applying components based on crash stacktrace and information from OWNERS files.

If this is incorrect, please apply the Test-Predator-Wrong-Components label.

Automatically assigning owner based on suspected regression changelist https://chromium.googlesource.com/chromium/src/+/fed2c859128b1a97ded6b611fa5cd7c68bc30bcb (Round aw contents size when converting it to CSS pixels).

If this is incorrect, please let us know why and apply the Test-Predator-Wrong-CLs label. If you aren't the correct owner for this issue, please unassign yourself as soon as possible so it can be re-triaged.

awhalley@ assigning it to you since jaebaek@ is not on the team anymore.

Thanks. Removing owner and setting to Unassigned so it'll get picked up by the security sheriff.

And adding Test-Predator-Wrong since it looks like automatic assignment doesn't cover this case.

cbiesinger: This looks like an issue with layout_block or layout_block_flow, can you take a look? (And reassign if appropriate). Thanks.

boliu: You were a reviewer on the CL that clusterfuzz points to, I don't think the CL is related in this case, but can you take a look? Thanks.

M67 Stable promotion is coming soon. Your bug is labelled as Stable ReleaseBlock, pls make sure to land the fix and request a merge into the release branch ASAP. Thank you.

cbiesinger: Uh oh! This issue still open and hasn't been updated in the last 14 days. This is a serious vulnerability, and we want to ensure that there's progress. Could you please leave an update with the current status and any potential blockers?

If you're not the right owner for this issue, could you please remove yourself as soon as possible or help us find the right one?

If the issue is fixed or you can't reproduce it, please close the bug. If you've started working on a fix, please set the status to Started.

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

Hi cbiesinger@, have you been able to take a look? Minimized test case seems to crash pretty reliably.

ClusterFuzz has detected this issue as fixed in range 555009:555011.

Detailed report: https://clusterfuzz.com/testcase?key=5780046216953856

Fuzzer: ochang_domfuzzer
Job Type: linux_asan_chrome_mp
Platform Id: linux

Crash Type: Heap-use-after-free READ 8
Crash Address: 0x61200003a100
Crash State:
  blink::LayoutBlockFlow::XPositionForFloatIncludingMargin
  blink::LayoutBlockFlow::AddOverflowFromFloats
  blink::LayoutBlock::SimplifiedLayout
  
Sanitizer: address (ASAN)

Recommended Security Severity: High

Regressed: https://clusterfuzz.com/revisions?job=linux_asan_chrome_mp&range=526624:526625
Fixed: https://clusterfuzz.com/revisions?job=linux_asan_chrome_mp&range=555009:555011

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5780046216953856

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 5780046216953856 is verified as fixed, so closing issue as verified.

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

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