Re: [PATCH] block: Check ADMIN before NICE for IOPRIO_CLASS_RT

From: Alistair Delva
Date: Mon Nov 15 2021 - 19:57:40 EST


On Mon, Nov 15, 2021 at 10:04 AM Jens Axboe <axboe@xxxxxxxxx> wrote:
>
> On 11/15/21 10:38 AM, Alistair Delva wrote:
> > Booting to Android userspace on 5.14 or newer triggers the following
> > SELinux denial:
> >
> > avc: denied { sys_nice } for comm="init" capability=23
> > scontext=u:r:init:s0 tcontext=u:r:init:s0 tclass=capability
> > permissive=0
> >
> > Init is PID 0 running as root, so it already has CAP_SYS_ADMIN. For
> > better compatibility with older SEPolicy, check ADMIN before NICE.
>
> Seems a bit wonky to me, but the end result is the same.

No argument from me..

> In any case,
> this warrants a comment above it detailing why the ordering is
> seemingly important.

Sent v2.

> --
> Jens Axboe
>