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From: Johannes Weiner <hannes@cmpxchg.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Hunt <johunt@akamai.com>, Ingo Molnar <mingo@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files
Date: Thu, 1 Apr 2021 15:47:57 -0400	[thread overview]
Message-ID: <YGYjbcqThAVOi8kP@cmpxchg.org> (raw)
In-Reply-To: <YGVshWmKgZgIgBKd@hirez.programming.kicks-ass.net>

On Thu, Apr 01, 2021 at 08:47:33AM +0200, Peter Zijlstra wrote:
> On Wed, Mar 31, 2021 at 11:31:56PM -0400, Josh Hunt wrote:
> > Currently only root can write files under /proc/pressure. Relax this to
> > allow tasks running as unprivileged users with CAP_SYS_RESOURCE to be
> > able to write to these files.
> > 
> > Signed-off-by: Josh Hunt <johunt@akamai.com>
> 
> I suppose that's ok, but lets also ask Johannes.

The write creates a kthread that runs as SCHED_FIFO. For userspace
threads this is reserved for CAP_SYS_NICE tasks, but it's a kernel
thread and not arbitrary code, so I suppose CAP_SYS_RESOURCE is fine.

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

      reply	other threads:[~2021-04-01 19:48 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-01  3:31 [PATCH] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files Josh Hunt
2021-04-01  4:36 ` Eric W. Biederman
2021-04-01  7:50   ` Kees Cook
2021-04-01 17:47     ` Eric W. Biederman
2021-04-01 18:10       ` Josh Hunt
2021-04-01  6:47 ` Peter Zijlstra
2021-04-01 19:47   ` Johannes Weiner [this message]

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