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From: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Oleg Nesterov <oleg@redhat.com>, Ingo Molnar <mingo@kernel.org>,
	Kees Cook <keescook@chromium.org>
Subject: Re: [patch 5/6] posix-cpu-timers: Sanitize thread clock permissions
Date: Thu, 5 Sep 2019 16:11:10 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.21.1909051610200.1902@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20190905122108.GO2349@hirez.programming.kicks-ass.net>

On Thu, 5 Sep 2019, Peter Zijlstra wrote:

> On Thu, Sep 05, 2019 at 02:03:44PM +0200, Thomas Gleixner wrote:
> > The thread clock permissions are restricted to tasks of the same thread
> > group, but that also prevents a ptracer from reading them. This is
> > inconsistent vs. the process restrictions and unnecessary strict.
> > 
> > Relax it to ptrace permissions in the same way as process permissions are
> > handled.
> 
> More of a meta comment on the added permission checking; so where
> clock_getcpuclockid() is allowed to return -EPERM, it doesn't because
> that's in glibc and it has no clue.
> 
> And these patches implement the ptrace checks and result in -EINVAL for
> timer_create() and clock_gettime(), even though it should arguably be
> -EPERM, but we're not allowed to return that here.

Yeah. Maybe we should nevertheless.

Thanks,

	tglx

  reply	other threads:[~2019-09-05 14:20 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-05 12:03 [patch 0/6] posix-cpu-timers: Fallout fixes and permission tightening Thomas Gleixner
2019-09-05 12:03 ` [patch 1/6] posix-cpu-timers: Always clear head pointer on dequeue Thomas Gleixner
2019-09-05 15:49   ` Frederic Weisbecker
2019-09-05 12:03 ` [patch 2/6] posix-cpu-timers: Fix permission check regression Thomas Gleixner
2019-09-05 17:31   ` Frederic Weisbecker
2019-09-05 18:55     ` Thomas Gleixner
2019-09-05 21:15       ` [patch V2 " Thomas Gleixner
2019-09-09 15:13         ` Frederic Weisbecker
2019-09-10 11:18         ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-09-05 12:03 ` [patch 3/6] posix-cpu-timers: Restrict timer_create() permissions Thomas Gleixner
2019-09-21  0:44   ` Frederic Weisbecker
2019-09-05 12:03 ` [patch 4/6] posix-cpu-timers: Restrict clock_gettime() permissions Thomas Gleixner
2019-09-23 13:39   ` Frederic Weisbecker
2019-09-05 12:03 ` [patch 5/6] posix-cpu-timers: Sanitize thread clock permissions Thomas Gleixner
2019-09-05 12:21   ` Peter Zijlstra
2019-09-05 14:11     ` Thomas Gleixner [this message]
2019-09-23 14:03   ` Frederic Weisbecker
2019-09-05 12:03 ` [patch 6/6] posix-cpu-timers: Make PID=0 and PID=self handling consistent Thomas Gleixner
2019-09-23 14:13   ` Frederic Weisbecker
2019-09-23 14:17     ` Thomas Gleixner
2019-09-05 14:48 ` [patch 0/6] posix-cpu-timers: Fallout fixes and permission tightening Frederic Weisbecker
2019-09-05 14:57   ` Thomas Gleixner
2019-09-05 15:21     ` Frederic Weisbecker
2019-09-05 20:32 ` Kees Cook
2019-09-05 21:13   ` Thomas Gleixner

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