From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
"Sylvain 'ythier' Hitier" <sylvain.hitier@gmail.com>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Vince Weaver <vincent.weaver@maine.edu>
Subject: Re: [PATCH] fork.c: copy_process(): fix cleanup WRT perf_event_free_task()
Date: Mon, 29 Sep 2014 16:00:48 +0200 [thread overview]
Message-ID: <20140929140048.GK5430@worktop> (raw)
In-Reply-To: <20140929120722.GA11943@gmail.com>
On Mon, Sep 29, 2014 at 02:07:22PM +0200, Ingo Molnar wrote:
>
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > Subject: perf: Fix perf bug in fork()
> >
> > Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by
> > calling perf_event_free_task() when failing sched_fork() we will not yet
> > have done the memset() on ->perf_event_ctxp[] and will therefore try and
> > 'free' the inherited contexts, which are still in use by the parent
> > process. This is bad..
> >
> > Suggested-by: Oleg Nesterov <oleg@redhat.com>
> > Reported-by: Oleg Nesterov <oleg@redhat.com>
> > Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com>
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
>
> Could this fix a couple of fuzzer triggered perf crashes perhaps?
It could indeed I suppose.. you never know what paths those fuzzers
manage to hit.
next prev parent reply other threads:[~2014-09-29 14:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-26 21:06 [PATCH] fork.c: copy_process(): fix cleanup WRT perf_event_free_task() Sylvain 'ythier' Hitier
2014-09-27 18:07 ` Oleg Nesterov
2014-09-29 10:12 ` Peter Zijlstra
2014-09-29 12:07 ` Ingo Molnar
2014-09-29 14:00 ` Peter Zijlstra [this message]
2014-10-01 22:44 ` Andrew Morton
2014-09-29 22:28 ` Oleg Nesterov
2014-10-03 5:27 ` [tip:perf/urgent] perf: Fix perf bug in fork() tip-bot for Peter Zijlstra
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