Bug#830144: systemd-container: machinectl segfaults trying to enable a new container

[Vasudev Kamath]

Package: systemd-container
Version: 230-5
Severity: important

Dear Maintainer,

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

   * What led up to the situation?

I created a new chroot at /var/lib/machines called localrepo using my
home grown script ¹

 bootstrap_debian --arch=i386 sid localrepo \
     http://localhost:3142/deb.debian.org/debian

After creating I ran machinectl to enable the container

machinectl enable localrepo

And I got a segfault.

¹ https://github.com/copyninja/bin/blob/master/bootstrap_debian

   * What outcome did you expect instead?

It should create a symlink systemd-nspawn at localrepo.service and do a
normal exit. In my case symbolic link is created but then there is a
segfault.

I got the -dbgsym package from unstable-debug and ran with gdb to get
backtrace. which is as follows

(gdb) bt
#0  0xf7e55ccb in bus_deserialize_and_dump_unit_file_changes (m=0x5656a7d0, quiet=false, changes=0x0, n_changes=0x0)
    at ../src/shared/bus-unit-util.c:893
#1  0x5655ced9 in enable_machine.lto_priv.20 (argc=2, argv=0xffffd788, userdata=0x56568850) at ../src/machine/machinectl.c:1665
#2  0xf7ec3db9 in dispatch_verb (argc=3, argv=0xffffd784, verbs=0x56566840 <verbs>, userdata=0x56568850) at ../src/basic/verbs.c:92
#3  0x56557975 in machinectl_main () at ../src/machine/machinectl.c:2742
#4  main (argc=3, argv=0xffffd784) at ../src/machine/machinectl.c:2765

Looks like there is a NULL pointer dereference for changes and
n_changes in line 893 of bus-unit-util.c which is

        unit_file_dump_changes(0, NULL, *changes, *n_changes, false);

If any more information is needed please let me know.


Cheers,

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

Kernel: Linux 4.6.0-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages systemd-container depends on:
ii  libacl1          2.2.52-3
ii  libblkid1        2.28-5
ii  libbz2-1.0       1.0.6-8
ii  libc6            2.22-11
ii  libcurl3-gnutls  7.47.0-1
ii  libgcc1          1:6.1.1-6
ii  libgcrypt20      1.7.0-2
ii  liblzma5         5.1.1alpha+20120614-2.1
ii  libseccomp2      2.3.1-2
ii  libselinux1      2.5-3
ii  systemd          230-5
ii  zlib1g           1:1.2.8.dfsg-2+b1

Versions of packages systemd-container recommends:
ii  btrfs-progs        4.5.2-1
ii  btrfs-tools        4.5.2-1
pn  libnss-mymachines  <none>

systemd-container suggests no packages.

-- no debconf information