Leak in xdg-permission-store when deleting data after uninstalling package

[ranisalt]

Hello! I'm facing an issue where the process for xdg-permission-store where it allocates huge loads of memory whenever an uninstalled package is deleting data, i.e. when running flatpak remove --delete-data <package> after pressing y when it prompts Delete data for <package>? [y/n].

This causes memory usage to ramp up very quickly, and it never deallocates. I'm talking about gigabytes on each uninstall, I just removed two packages (com.github.wwmm.easyeffects and org.freedesktop.LinuxAudio.Plugins.LSP) and xdg-permission-store is sitting at ~6 GB memory usage. It increases about 3 GB for each package, until it uses 100% of my RAM and crashes the system, requiring a hard reset.

After uninstalling 2 more packages, it peaked at 10.6 GB:

Killing the process does not seem to cause any issues. I don't know of any logs to annex, but am willing to share whatever information is necessary to fix ;)

[ranisalt]

Update: this seems to heavily affect the cleanup process, it takes several minutes to remove packages even if they have almost no data in disk, and I have a fast SSD.

[Mikenux]

I can't reproduce the RAM bug with xdg-desktop-portal 1.18.2 (Fedora 39, GNOME). I monitored that with System Monitor from GNOME. However, I am able to reproduce the high disk write activity.

@ranisalt: Are you able to reproduce with a more recent xdg-desktop-portal version (ideally, the latest: 1.18.2)?

[Mikenux]

Better with numbers.

OS: Fedora Linux 39, GNOME 45.1, xdg-desktop-portal 1.18.2.

I used System Monitor from GNOME to monitor memory usage of xdg-permission-store.

I used the following commands, two times:
flatpak install Kamoso: I made a system install. The app comes from flathub repository. It installs: org.kde.KStyle. Adwaita, org.kde.Platform.Locale, org.kde.PlatformTheme.QGnomePlatform, org.kde.WaylandDecoration.QAdwaitaDecorations, org.kde.WaylandDecoration.QGnomePlatform-decoration, org.kde.Platform, and org.kde.kamoso.locale, org.kde.kamoso
flatpak remove --delete-data Kamoso
flatpak remove --unused --delete data

I also launched Text Editor (flatpak) to take notes.

Numbers:

• Resident Memory: 6.2 MB -> 6.3 MB (Text Editor launch) -> 8.1 to 8.3 MB (remove --delete-data Kamoso) -> 8.5 MB (remove --unused --delete-data) -> 8.6 to 8.7 MB (remove --unused --delete-data, second time))
• Shared Memory: 5.8 MB -> 5.9 MB (Text Editor launch) -> 6.6 MB (remove --delete-data Kamoso) -> 6.6 MB (no change in second time)
• Memory: 392.2 KB -> 1.8 MB (Kamoso --delete-data) -> 1.9 MB (remove --unused --delete-data) -> 2.1 to 2.2 MB (remove --unused --delete-data, second time)

This bug is also a duplicate of #748 (where I took the Kamoso example).

[hfiguiere]

When I try to run this with the xdg-permission-store run under valgrind, I get the --delete-data hung.

[incloxe]

Just cross-posted over at #748. System is at 11.8GB memory usage for xdg-permission-store & can also say that the --delete-data hangs abnormally long.

One thing to note is that initially my system was hanging with --delete-data, but the memory leak had not yet occurred. Only recently did the memory leak happen.

Starting fresh will solve things, but I'm interested in the outcome of the issue.