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
next prev parent 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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