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Date: Tue, 24 Jan 2017 14:49:18 +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
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On Tue, Jan 24, 2017 at 02:29:19PM +0100, Dmitry Vyukov wrote:
> 
> Try to run more parallel processes at the same time.
> This program will run 32 processes in a tight loop:
> https://gist.githubusercontent.com/dvyukov/b36aa4398bb016923278fccdd1cc5b45/raw/9607078fd5ac2daf769c13d82561a83e17b06032/gistfile1.txt
> It triggered the UAF in several minutes for me. I have 4 CPUs in the
> VM. If you have more, set number of processes to 8*CPU.

No VM here, I'll up to 320 processes.