Re: Bug#1132588: runuser: missing whitelist-environment option

[Chris Hofstaedtler <zeha@debian.org>]

[CC'ing upstream]

On Fri, Apr 03, 2026 at 11:57:46AM +0200, Katie May wrote:
> Package: util-linux
> Version: 2.42-1
> 
> Dear Maintainer,
> 
> runuser no longer accepts the whitelist-environment option (both in long
> and short form) despite it still being listed in the man page.
> 
> For example, without specifying whitelist, runuser works
> ```
> # runuser -l test -c id
> uid=12345(test) gid=12345(test) groups=12345(test)
> ```
> 
> But if I specify an environment variable to whitelist I get an error
> ```
> # runuser -l test -w MY_VAR -c id
> -sh: 0: Illegal option -w
> ```

It appears to work when placing the options in a different order, 
f.e. this works:

  # MY_VAR=foo runuser -w MY_VAR -l root -c env

Notably the placement of the -l option and the username seem to be 
the problem.

I'll note that `MY_VAR=foo runuser -l root -w MY_VAR -c env` worked in 2.41.

Maybe ac0147fd14b348097c82c1c89a5417b582e26bad broke this?

| commit ac0147fd14b348097c82c1c89a5417b582e26bad
| Author:     cgoesche <cgoesc2@wgu.edu>
| AuthorDate: Sun Nov 2 11:55:09 2025 -0500
| Commit:     cgoesche <cgoesc2@wgu.edu>
| CommitDate: Mon Nov 3 13:16:19 2025 -0500
| 
|     su: pass arguments after <user> to shell
| 
|     The su(1) manpage describes how the arguments after <user>
|     are passed to the invoked shell. However this is empirically
|     wrong, as option flags after <user> are interpreted by su(1)
|     and will eventually never be passed or yield an error that
|     terminates the program due to an unrecognized option flag.
| 
|     To fix this we can change getopt(3)'s scanning mode with a '+'
|     prefixed to 'optstring', this will make it so that getopt(3)
|     stops processing argv elements on the first occurrence of a
|     non-option argument, e.g. '-' or '<user>'.
| 
|     Additionally, if the argument that directly follows '-' is an
|     option flag, su(1) will assume that this argument and the ones
|     that follow, are to be passed to a shell invoked by the root user.
| 
|     Addresses: https://github.com/util-linux/util-linux/pull/1809
|     Signed-off-by: cgoesche <cgoesc2@wgu.edu>


Chris