[pkg-lxqt-devel] Bug#965096: lxqt: LXQt Mount dialog hangs unresponsive when inserting LUKS encrypted USB volume

[Bernhard Bodenstorfer]

Package: lxqt
Version: 29
Severity: normal
Tags: a11y

Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

The issue appeared from the beginning, right after the fresh installations of Debian 10.3 and 10.4 likewise with LXQt.

I have prepared a USB memory stick with two partitions shown as sdb1 and sdb4.
(The problem also affects at least one other similar USB-disk.)
The former partition sdb1 is just plain ext2, the latter is LUKS encrypted dos or ext2 file system
(I tried both file systems, both yield the hang, as I would expect, because before decryption the filesystem should be unknown to LXQt).
Note: When at earlier times, sdb4 carried just a plain ext2, the bug did not appear, so the memory stick appears physically undamaged.

The commands to create the encrypted drive were on the root command line (4 being the alias for /dev/dm-0)
/sbin/cryptsetup luksFormat /dev/sdb4
/sbin/cryptsetup open /dev/sdb4 4
/sbin/mkdosfs -n SDIG4 /dev/dm-0
/sbin/cryptsetup close 4

Note that in the same session, directly after creation of the encrypted partition, unplugging and re-plugging the device did work fine and LXQt would properly ask for password and mount the encrypted partition as expected.

The bug, however, shows after a re-start of the computer. In this case, when I plug in the device, a Mount dialog comes up, but is immediately frozen (see attached unresponsive dialog screenshot). When I switch desktops hence and forth, the hanging dialog window keeps the background from the other desktop, i.e. does not refresh with its own content (see attached black dialog screenshot).

I can close the dialog window (accepting the warning "This window might be busy and is not responding. Do you want to terminate the application?"), and the LXQt desktop will grey out, leaving only the panel and my active windows, but no desktop icons.

When I log out and log in again, I can repeat the freeze by plugging in the device again.

--- WORK-AROUND ---

When the device with the encrypted partition is connected, I can still explicitly mount the volume from the root command line:
/sbin/cryptsetup open /dev/sdb4 4
This subsequently triggers a dialog asking for the root password and then mounts the device.

*** End of the template - remove these template lines ***


-- System Information:
Debian Release: 10.4
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 4.19.0-9-686 (SMP w/2 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages lxqt depends on:
ii  featherpad                             0.9.4-2
ii  lximage-qt                             0.14.1-1
ii  lxqt-about                             0.14.1-1
ii  lxqt-admin                             0.14.1-1
ii  lxqt-branding-debian [lxqt-branding]   0.14.0.3
ii  lxqt-core                              29
ii  lxqt-openssh-askpass                   0.14.1-1
ii  lxqt-powermanagement                   0.14.1-1
ii  lxqt-sudo                              0.14.1-2
ii  openbox [x-window-manager]             3.6.1-8
ii  pavucontrol                            3.0-4
ii  pavucontrol-qt                         0.14.1-1
ii  qlipper                                1:5.1.2-1
ii  qps                                    1.10.20-1
ii  qterminal                              0.14.1-1
ii  qttranslations5-l10n                   5.11.3-2
ii  sddm-theme-debian-elarun [sddm-theme]  0.18.0-1
ii  sddm-theme-debian-maui [sddm-theme]    0.18.0-1
ii  xarchiver                              1:0.5.4.14-1
ii  xfwm4 [x-window-manager]               4.12.5-1

Versions of packages lxqt recommends:
ii  audacious                  3.10.1-1
ii  cmst                       2019.01.13-1
ii  feathernotes               0.4.6-1
ii  firefox-esr [www-browser]  68.10.0esr-1~deb10u1
ii  gucharmap                  1:11.0.3-3
ii  lynx [www-browser]         2.8.9rel.1-3
ii  meteo-qt                   1.0.0-1
ii  network-manager-gnome      1.8.20-1.1
pn  preload                    <none>
ii  qpdfview                   0.4.17~beta1+git20180709-2
ii  quassel                    1:0.13.1-1+deb10u2
ii  screengrab                 1.101-1
ii  smplayer                   18.10.0~ds0-1
ii  smtube                     18.3.0-1
ii  thunderbird                1:68.10.0-1~deb10u1

Versions of packages lxqt suggests:
pn  calibre            <none>
pn  compton-conf       <none>
pn  juffed             <none>
pn  nomacs             <none>
pn  obconf-qt          <none>
pn  qt5-style-kvantum  <none>
pn  qtpass             <none>
pn  shutter            <none>
pn  vokoscreen         <none>

-- no debconf information