Re: [PATCH v5 next 0/5] Improve Module autoloading infrastructure

From: James Morris
Date: Mon Nov 27 2017 - 17:33:03 EST


On Tue, 28 Nov 2017, David Miller wrote:

> From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Date: Mon, 27 Nov 2017 10:41:30 -0800
>
> > What are the real life use-cases for normal users having modules
> > auto-load?
>
> User opens SCTP socket, SCTP protocol module loads.
>
> People build test cases via namespaces, and in that namespaces normal
> users can setup virtual tunnel devices themselves, and those configure
> operations can bring the tunnel module in.

What about implementing a white list of modules which are able to be
loaded by unprivileged users?

Then, Linus' solution would look something like:

va_start(args, fmt);
ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
va_end(args);

if (WARN_ON_ONCE(!capable(CAP_SYS_MODULE) ||
!capable(CAP_SYS_ADMIN) ||
!capable(CAP_NET_ADMIN) ||
!unprivileged_autoload(module_name)))
return -EPERM;



--
James Morris
<james.l.morris@xxxxxxxxxx>