[Pkg-shadow-devel] Bug#1076619: passwd: /etc/group file corruption with usernames ending in blackslash

[Chris Hofstaedtler]

Control: retitle -1 passwd: /etc/group file corruption with usernames ending in blackslash

On Sat, Jul 20, 2024 at 01:40:24AM +0530, vijai kumar wrote:
> This happens when a username ending with backslash which belongs to a
> group is being deleted.
> 
> Steps to reproduce:
> $ useradd 'vijai\'
> $ usermod -aG sudo 'vijai\'
> $ userdel 'vijai\'

I'll note that userdel is not necesary. The following sequence also
breaks /etc/group:

$ useradd 'vijai\'
$ usermod -aG sudo 'vijai\'
$ useradd blafasel
$ usermod -aG sudo blafasel

Results in:
  sudo:x:27:install,vijaiaudio:x:29:install

Should have been:
  sudo:x:27:install,vijai\,blafasel
  audio:x:29:install


Chris