Bug#954174: login broken for usernames starting with a number (badname)

[Michael Biebl]

Package: systemd
Version: 245-2
Severity: serious
Forwarded: https://github.com/systemd/systemd/issues/15141


Usernames that contain a number (or digit) as first character are
rejected by v245:
https://github.com/systemd/systemd/blob/v245/src/basic/user-util.c#L710
This will lead to login failures.

By default, adduser will not allow such usernames to be created, but can
be forced to do so via --force-badname.

While a leading dot is really questionable, the validation should be
relaxed for a leading number.



-- Package-specific info:

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (200, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

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

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            2.30-2
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         27-2
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      2.4.3-1
ii  libselinux1      3.0-1+b1
ii  libsystemd0      245-2
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
ii  systemd-container  245-2

Versions of packages systemd is related to:
ii  dracut           048+80-2
pn  initramfs-tools  <none>
ii  libnss-systemd   245-2
ii  libpam-systemd   245-2
ii  udev             245-2

-- no debconf information