Bug#935091: systemd: sync_file_range fails in nspawn containers on arm, ppc

[Stefan Haller]

Package: systemd
Version: 241-5
Severity: normal

Dear Maintainer,

the systemd-nspawn syscall filter is incomplete and does not whitelist
the sync_file_range2 syscall. ARM has two sync_file_range syscalls,
sync_file_range and sync_file_range2. The former is apparently not used,
and glibc calls the latter whenever a userspace program calls
sync_file_range. Hence every program using this syscall's glibc wrapper
inside a systemd-nspawn container on ARM (and probably PPC) will fail.

A similar report filed for Ubuntu bionic contains additional information
and example code that will fail in the given situation:

  <https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1840640>

The bug affects packages like borgbackup and postgres in those
environments:

  <https://github.com/borgbackup/borg/issues/4710>
  <https://www.postgresql.org/message-id/flat/CA%2BhUKG%2BydOUT4zjxb6QmJWy8U9WbC-q%2BJWV7wLsEY9Df%3Dmw0Mw%40mail.gmail.com#ac8f14897647dc7eae3c7e7cbed36d93>

A very straight-forward fix is present in
<https://github.com/systemd/systemd/pull/13352>.

Best regards,
Stefan Haller

-- Package-specific info:

-- System Information:
Debian Release: 10.0
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: armhf (armv7l)

Kernel: Linux 4.19.50-v7l+ (SMP w/4 CPU cores)
Kernel taint flags: TAINT_WARN, TAINT_CRAP
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages systemd depends on:
ii  adduser          3.118
ii  libacl1          2.2.53-4
ii  libapparmor1     2.13.2-10
ii  libaudit1        1:2.8.4-3
ii  libblkid1        2.33.1-0.1
ii  libc6            2.28-10
ii  libcap2          1:2.25-2
ii  libcryptsetup12  2:2.1.0-5
ii  libgcrypt20      1.8.4-5
ii  libgnutls30      3.6.7-4
ii  libgpg-error0    1.35-1
ii  libidn11         1.33-2.2
ii  libip4tc0        1.8.2-4
ii  libkmod2         26-1
ii  liblz4-1         1.8.3-1
ii  liblzma5         5.2.4-1
ii  libmount1        2.33.1-0.1
ii  libpam0g         1.3.1-5
ii  libseccomp2      2.3.3-4
ii  libselinux1      2.8-1+b1
ii  libsystemd0      241-5
ii  mount            2.33.1-0.1
ii  util-linux       2.33.1-0.1

Versions of packages systemd recommends:
ii  dbus            1.12.16-1
ii  libpam-systemd  241-5

Versions of packages systemd suggests:
pn  policykit-1        <none>
ii  systemd-container  241-5

Versions of packages systemd is related to:
pn  dracut           <none>
pn  initramfs-tools  <none>
pn  udev             <none>

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

-- no debconf information