On Mon, Mar 6, 2017 at 1:23 PM, Peter Zijlstra wrote: > On Mon, Mar 06, 2017 at 01:17:42PM +0100, Dmitry Vyukov wrote: >> On Mon, Mar 6, 2017 at 1:13 PM, Peter Zijlstra 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. > > I'll try. Thanks! I think you will also need the attached patch. It seems that it was found due to it. Going to send it out soon.