On Sun, Nov 18, 2012 at 8:05 PM, Sasha Levin <[email protected]> wrote: > Hi Kees, > > On Thu, Oct 18, 2012 at 6:39 PM, Kees Cook <[email protected]> wrote: >> On Wed, Oct 17, 2012 at 8:10 PM, Sasha Levin <[email protected]> wrote: >>> Hi all, >>> >>> I was fuzzing with trinity within a KVM tools guest (lkvm) on a linux-next >>> kernel, and got the >>> following dump which I believe to be noise due to how the timers work - but >>> I'm not 100% sure. >>> ... >>> [ 954.674123] Possible interrupt unsafe locking scenario: >>> [ 954.674123] >>> [ 954.674123] CPU0 CPU1 >>> [ 954.674123] ---- ---- >>> [ 954.674123] lock(ptracer_relations_lock); >>> [ 954.674123] local_irq_disable(); >>> [ 954.674123] >>> lock(&(&new_timer->it_lock)->rlock); >>> [ 954.674123] lock(ptracer_relations_lock); >>> [ 954.674123] <Interrupt> >>> [ 954.674123] lock(&(&new_timer->it_lock)->rlock); >>> [ 954.674123] >>> [ 954.674123] *** DEADLOCK *** >> >> I've been wanting to get rid of the Yama ptracer_relations_lock >> anyway, so maybe I should do that now just to avoid this case at all? > > I still see this one in -rc6, is there anything to get rid of it > before the release?
I'm not sure about changes to the timer locks, but I haven't been able to get rid of the locking on Yama's task_free path. I did send a patch to get rid of locking during a read, though: https://lkml.org/lkml/2012/11/13/808 -Kees -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
