From: Thomas Gleixner <tglx@linutronix.de>
To: Frederic Weisbecker <frederic@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Oleg Nesterov <oleg@redhat.com>, Ingo Molnar <mingo@kernel.org>,
Kees Cook <keescook@chromium.org>
Subject: Re: [patch 2/6] posix-cpu-timers: Fix permission check regression
Date: Thu, 5 Sep 2019 20:55:22 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1909052054200.1902@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20190905173148.GE18251@lenoir>
On Thu, 5 Sep 2019, Frederic Weisbecker wrote:
> On Thu, Sep 05, 2019 at 02:03:41PM +0200, Thomas Gleixner wrote:
> > + if (gettime) {
> > + /*
> > + * For clock_gettime() the task does not need to be the
> > + * actual group leader. tsk->sighand gives access to the
> > + * group's clock.
> > + */
>
> I'm a bit confused with the explanation. Why is it fine to do so with clock
> and not with timer? tsk->sighand gives access to the group's timer as
> well.
Timer stores the target task and that's the group leader for process wide
while clock read is just momentary. Lemme rephrase that.
Thanks,
tglx
next prev parent reply other threads:[~2019-09-05 18:55 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 [this message]
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
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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