1967108 - Crash in [@ mozilla::EnumSet<T>::operator-=]

Status: NEW

(Core :: Web Painting, defect)

Description

[BugBot [:suhaib / :marco]]

Crash report: https://crash-stats.mozilla.org/report/index/30ffb5dd-b32e-407c-b33a-0f64e0250511

Reason: EXCEPTION_ACCESS_VIOLATION

Top 10 frames of crashing thread:

0  xul.dll  mozilla::EnumSet<mozilla::nsDisplayItem::ItemFlag, unsigned short>::operator-=  mfbt/EnumSet.h:106
0  xul.dll  mozilla::nsDisplayItem::SetItemFlag  layout/painting/nsDisplayList.h:2851
0  xul.dll  mozilla::nsDisplayItem::SetMergedPreProcessed  layout/painting/nsDisplayList.h:2874
0  xul.dll  mozilla::RetainedDisplayListBuilder::PreProcessDisplayList  layout/painting/RetainedDisplayListBuilder.cpp:195
1  xul.dll  mozilla::RetainedDisplayListBuilder::PreProcessDisplayList  layout/painting/RetainedDisplayListBuilder.cpp:277
2  xul.dll  mozilla::RetainedDisplayListBuilder::PreProcessDisplayList  layout/painting/RetainedDisplayListBuilder.cpp:277
3  xul.dll  mozilla::RetainedDisplayListBuilder::AttemptPartialUpdate  layout/painting/RetainedDisplayListBuilder.cpp:1597
3  xul.dll  nsLayoutUtils::PaintFrame  layout/base/nsLayoutUtils.cpp:3144
4  xul.dll  mozilla::PresShell::PaintInternal  layout/base/PresShell.cpp:6711
5  xul.dll  nsViewManager::ProcessPendingUpdatesPaint  view/nsViewManager.cpp:399

By querying Nightly crashes reported within the last 2 months, here are some insights about the signature:

• First crash report: 2025-04-06
• Process type: Content
• Is startup crash: No
• Has user comments: No
• Is null crash: Yes - 3 out of 4 crashes happened on null or near null memory address