Re: perf: use-after-free in perf_release

[Dmitry Vyukov]

On Mon, Mar 6, 2017 at 1:13 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Mon, Mar 06, 2017 at 10:57:07AM +0100, Dmitry Vyukov wrote:
>> Hello,
>>
>> I've got the following use-after-free report while running syzkaller
>> fuzzer on 86292b33d4b79ee03e2f43ea0381ef85f077c760. Note that the task
>> is freed right in copy_process due to some error, but it's referenced
>> by another thread in perf subsystem.
>
> Weird... you don't happen to have a reproduction case available?


Unfortunately no. I've looked at both logs that I have and there are
no memory allocation failures preceding the crash (however maybe
somebody used NOWARN?). But probably if you inject an error into
copy_process somewhere after perf_event_init_task, it should reproduce
the bug with KASAN I think.