Bug#953670: systemd: uncommanded switch to Plymouth boot screen

[Ben Caradoc-Davies]

Package: systemd
Version: 245-1
Severity: critical
Justification: breaks the whole system

Dear Maintainer,

about 20 minutes after boot, regardless of what the user is doing, the
graphical desktop is replaced with an unresponsive Plymouth boot screen. It
looks like this is on virtual console one. The X desktop can be restored by
pressing Alt-F7. Users unaware that they can switch back to X with Alt-F7 are
completely locked out. Other virtual consoles can be selected. The system
remains up. Rogue timer?

Behaviour started today after upgrade:

libsystemd0:amd64 (244.3-1, 245-1)
udev:amd64 (244.3-1, 245-1)
libudev1:amd64 (244.3-1, 245-1)
libudev-dev:amd64 (244.3-1, 245-1)
systemd-sysv:amd64 (244.3-1, 245-1)
libpam-systemd:amd64 (244.3-1, 245-1)
systemd:amd64 (244.3-1, 245-1)
libnss-systemd:amd64 (244.3-1, 245-1)

journalctl contains these log entries for the time at which the uncommanded
switch occurs:

Mar 12 14:12:56 ripley systemd[1]: Condition check resulted in FUSE Control
File System being skipped.
Mar 12 14:12:56 ripley systemd[1]: Condition check resulted in Kernel
Configuration File System being skipped.
Mar 12 14:12:56 ripley systemd[1]: Starting Wait for network to be configured
by ifupdown...
Mar 12 14:12:56 ripley systemd[1]: Starting Tell Plymouth To Write Out Runtime
Data...
Mar 12 14:12:56 ripley systemd[1]: Starting Show Plymouth Boot Screen...
Mar 12 14:12:56 ripley systemd[1]: Condition check resulted in Set Up
Additional Binary Formats being skipped.
Mar 12 14:12:56 ripley systemd[1]: Condition check resulted in Store a System
Token in an EFI Variable being skipped.
Mar 12 14:12:56 ripley systemd[1]: Condition check resulted in Rebuild Hardware
Database being skipped.
Mar 12 14:12:56 ripley systemd[1]: Condition check resulted in Commit a
transient machine-id on disk being skipped.
Mar 12 14:12:56 ripley systemd[1]: Received SIGRTMIN+20 from PID 1439
(plymouthd).
Mar 12 14:12:56 ripley systemd[1]: Finished Wait for network to be configured
by ifupdown.
Mar 12 14:12:56 ripley systemd[1]: plymouth-read-write.service: Succeeded.
Mar 12 14:12:56 ripley systemd[1]: Finished Tell Plymouth To Write Out Runtime
Data.
Mar 12 14:12:56 ripley systemd[1]: Starting Network Manager Wait Online...
Mar 12 14:12:56 ripley systemd[1]: Finished Network Manager Wait Online.
Mar 12 14:12:56 ripley systemd[1]: Reached target Network is Online.
Mar 12 14:12:56 ripley systemd[1]: Starting Daily apt-listbugs preferences
cleanup...
Mar 12 14:12:56 ripley systemd[1]: apt-listbugs.service: Succeeded.
Mar 12 14:12:56 ripley systemd[1]: Finished Daily apt-listbugs preferences
cleanup.
Mar 12 14:12:56 ripley systemd[1]: Started Show Plymouth Boot Screen.

Kind regards,
Ben.



-- Package-specific info:

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.4.0-4-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8), LANGUAGE=en_GB:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages systemd depends on:
ii  adduser          3.118
ii  libacl1          2.2.53-6
ii  libapparmor1     2.13.3-7
ii  libaudit1        1:2.8.5-2+b1
ii  libblkid1        2.34-0.1
ii  libc6            2.29-10
ii  libcap2          1:2.32-1
ii  libcrypt1        1:4.4.15-1
ii  libcryptsetup12  2:2.3.0-1
ii  libgcrypt20      1.8.5-5
ii  libgnutls30      3.6.12-2
ii  libgpg-error0    1.37-1
ii  libidn2-0        2.3.0-1
ii  libip4tc2        1.8.4-3
ii  libkmod2         27-1
ii  liblz4-1         1.9.2-2
ii  liblzma5         5.2.4-1+b1
ii  libmount1        2.34-0.1
ii  libpam0g         1.3.1-5
ii  libpcre2-8-0     10.34-7
ii  libseccomp2      2.4.2-2
ii  libselinux1      3.0-1+b1
ii  libsystemd0      245-1
ii  mount            2.34-0.1
ii  util-linux       2.34-0.1

Versions of packages systemd recommends:
ii  dbus  1.12.16-2

Versions of packages systemd suggests:
ii  policykit-1        0.105-26
pn  systemd-container  <none>

Versions of packages systemd is related to:
pn  dracut           <none>
ii  initramfs-tools  0.136
ii  libnss-systemd   245-1
ii  libpam-systemd   245-1
ii  udev             245-1

-- Configuration Files:
/etc/systemd/logind.conf changed [not included]

-- no debconf information