Re: [PATCH] Allow restricting permissions in /proc/sys

[Topi Miettinen]

On 3.11.2019 19.56, Theodore Y. Ts'o wrote:
> On Sun, Nov 03, 2019 at 04:55:48PM +0200, Topi Miettinen wrote:
> > Several items in /proc/sys need not be accessible to unprivileged
> > tasks. Let the system administrator change the permissions, but only
> > to more restrictive modes than what the sysctl tables allow.
> >
> > Signed-off-by: Topi Miettinen <toiwoton@xxxxxxxxx>
>
> Why should restruct the system administrator from changing the
> permissions to one which is more lax than what the sysctl tables?
>
> The system administrator is already very much trusted.  Why should we
> take that discretion away from the system administrator?

That could make sense, in addition changing UID/GID would allow even 
more flexibility. The current checks and restrictions which prevent 
those changes were already present in original code in 2007. I didn't 
want to change the logic too much. Perhaps loosening the restrictions 
could be a follow-up patch, as it may give chance to use more of generic 
proc or fslib code and thus a larger restructuring.

-Topi