Bug#883997: libkscreenlocker5: screen lock with photo slideshow eats up all memory and triggers oom killer

[Philipp Huebner <debalance@debian.org>]

Package: libkscreenlocker5
Version: 5.10.5.1-1
Severity: important

Hi,

I'm using the screenlocker's slideshow feature to display another photo
every 5 seconds out of a choice of ~4000.

After a couple of hours sddm freezes completely, no reaction to any
mouse or keyboard input, except the magic key combination ctrl+alt+b to force an
immediate reboot.

Looking at syslog after the reboot, I see that oom killer was triggered
several times, as there was no free RAM and no free SWAP left any more.
It also shows that libkscreenlocker5 is using by far the most memory,
and every time oom killer is invoked, libkscreenlocker5 is using even
more memory than before, e.g. total_vm 7549136 -> 7589587.

For reference: this box has 16 GB of memory + 16 GB of swap and only
runs standard office applications.


Regards,
Philipp


-- System Information:
Debian Release: buster/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (500, 'oldstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.14.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libkscreenlocker5 depends on:
ii  kpackagetool5         5.37.0-2
ii  libc6                 2.25-3
ii  libkf5configcore5     5.37.0-2
ii  libkf5configgui5      5.37.0-2
ii  libkf5coreaddons5     5.37.0-2
ii  libkf5crash5          5.37.0-2
ii  libkf5declarative5    5.37.0-2+b1
ii  libkf5globalaccel5    5.37.0-2
ii  libkf5i18n5           5.37.0-2
ii  libkf5idletime5       5.37.0-2
ii  libkf5notifications5  5.37.0-2
ii  libkf5package5        5.37.0-2
ii  libkf5quickaddons5    5.37.0-2+b1
ii  libkf5waylandclient5  4:5.37.0-2
ii  libkf5waylandserver5  4:5.37.0-2
ii  libkf5windowsystem5   5.37.0-2
ii  libpam0g              1.1.8-3.6
ii  libqt5core5a          5.9.2+dfsg-6
ii  libqt5dbus5           5.9.2+dfsg-6
ii  libqt5gui5            5.9.2+dfsg-6
ii  libqt5network5        5.9.2+dfsg-6
ii  libqt5qml5            5.9.2-3
ii  libqt5quick5          5.9.2-3
ii  libqt5widgets5        5.9.2+dfsg-6
ii  libqt5x11extras5      5.9.2-1
ii  libstdc++6            7.2.0-17
ii  libwayland-client0    1.14.0-1+b1
ii  libwayland-server0    1.14.0-1+b1
ii  libx11-6              2:1.6.4-3
ii  libxcb-keysyms1       0.4.0-1+b2
ii  libxcb1               1.12-1
ii  libxi6                2:1.7.9-1

Versions of packages libkscreenlocker5 recommends:
ii  kde-config-screenlocker  5.10.5.1-1

libkscreenlocker5 suggests no packages.

-- no debconf information