Public bug reported:
1) lsb_release -rd:
Description: Ubuntu Kylin 26.04
2) apt-cache policy pkgname:
Package: ukui-sidebar (4.20.1.3-0ubuntu1)
3) What you expected to happen:
When a popup notification is triggered (e.g., inserting a USB drive), the
notification should be displayed normally without causing any system components
to crash.
4) What happened instead:
Triggering a popup notification causes `ukui-sidebar` to immediately crash and
generate a coredump.
==============================================
SRU JUSTIFICATION
==============================================
[Impact]
On Ubuntu Kylin 26.04 (compiled with Qt6), the `ukui-sidebar` crashes 100% of
the time when a notification is triggered.
The root cause is a memory management issue in `src/layout/ukui-column.cpp`.
The layout engine used `QPODVector` and manual raw pointer deletion (`delete
transitionableItem`) for UI elements. When elements change (like popups
appearing/disappearing), it triggers `ItemChildRemovedChange`, leading to
memory corruption/segmentation faults in Qt6.
The patch resolves this by replacing `QPODVector` with standard `QVector` and
using `std::shared_ptr` for safe memory management.
[Test Plan]
1. Boot into Ubuntu Kylin 26.04.
2. Monitor the sidebar process and `/var/crash/`.
3. Trigger a system notification (e.g., plug in a USB flash drive).
4. Observe that `ukui-sidebar` crashes and disappears/restarts.
5. Enable `resolute-proposed` and update the `ukui-sidebar` package.
6. Restart the sidebar or reboot.
7. Plug in the USB drive again.
8. Verify the popup shows correctly and `ukui-sidebar` remains stable with no
new coredumps.
[Where problems could occur]
The patch modifies the core layout positioning logic (`UkuiBasePositioner`)
used by the sidebar. Since it changes how child items are stored and memory is
freed, potential regressions could include:
1. Memory leaks if `std::shared_ptr` creates circular references (highly
unlikely here).
2. UI rendering issues where notification items fail to animate, position
correctly, or disappear properly.
Testing should heavily focus on the rendering and dismiss animations of
multiple overlapping notifications.
** Affects: ukui-sidebar (Ubuntu)
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2151290
Title:
[SRU] ukui-sidebar crashes (coredump) when triggering popup
notifications
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/ukui-sidebar/+bug/2151290/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
