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Date: Tue, 24 Jan 2017 14:17:48 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        syzkaller <syzkaller@googlegroups.com>
Subject: Re: perf: use-after-free in perf_event_for_each
Message-ID: <20170124131748.GD6536@twins.programming.kicks-ass.net>
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On Mon, Jan 23, 2017 at 06:04:42PM +0100, Peter Zijlstra wrote:
> On Mon, Jan 23, 2017 at 02:30:12PM +0100, Dmitry Vyukov wrote:
> > Hello,
> > 
> > The following program triggers use-after-free in perf_event_for_each:
> > https://gist.githubusercontent.com/dvyukov/f1c354a8356e42f4d0b3d912e1bec956/raw/31d7ecdf6dc2c7327b80ef8581a39c823bbe405d/gistfile1.txt

I've been running 60 concurrent instances of that thing for hours now,
and have not been able to reproduce :-/

I did enable CONFIG_KASAN but otherwise booted as normal, and the thing
says:

[    0.000000] kasan: KernelAddressSanitizer initialized

Is there anything else I should do?

I've ran out of ideas and it would be very helpful if I could prod at
something that fails...