Re: [STABLE] kernel oops which can be fixed by peterz's patches

[Greg KH]

On Mon, Jul 18, 2016 at 03:31:46PM +0900, Byungchul Park wrote:
> On Tue, Mar 01, 2016 at 08:15:55AM +0000, Greg KH wrote:
> > On Tue, Jan 05, 2016 at 05:52:11PM +0900, Byungchul Park wrote:
> > > 
> > > Upstream commits to be applied
> > > ==============================
> > > 
> > > e3fca9e: sched: Replace post_schedule with a balance callback list
> > > 4c9a4bc: sched: Allow balance callbacks for check_class_changed()
> > > 8046d68: sched,rt: Remove return value from pull_rt_task()
> > > fd7a4be: sched, rt: Convert switched_{from, to}_rt() / prio_changed_rt() to balance callbacks
> > > 0ea60c2: sched,dl: Remove return value from pull_dl_task()
> > > 9916e21: sched, dl: Convert switched_{from, to}_dl() / prio_changed_dl() to balance callbacks
> > > 
> > > The reason why these should be applied
> > > ======================================
> > > 
> > > Our products developed using 3.16 kernel, faced a kernel oops which can
> > > be fixed with above upstreamed patches. The oops is caused by "Unable
> > > to handle kernel NULL pointer dereference at virtual address 000000xx"
> > > in the call path,
> > > 
> > > __sched_setscheduler()
> > > 	check_class_changed()
> > > 		switched_to_fair()
> > > 			check_preempt_curr()
> > > 				check_preempt_wakeup()
> > > 					find_matching_se()
> > > 						is_same_group()
> > > 
> > > by "if (se->cfs_rq == pse->cfs_rq) // se, pse == NULL" condition.
> > > 
> > > How to apply it
> > > ===============
> > > 
> > > For stable 4.2.8+:
> > > 	N/A (already applied)
> > > 
> > > For longterm 4.1.15:
> > > 	Cherry-picking the upsteam commits works with a trivial conflict.
> > > 
> > > For longterm 3.18.25:
> > > 	Refer to the backported patches in this thread.
> > > 
> > > For longterm 3.14.58:
> > > 	Refer to the backported patches in this thread. And applying
> > > 	additional "6c3b4d4: sched: Clean up idle task SMP logic" commit
> > > 	makes backporting the upstream commits much simpler. So my
> > > 	backporting patches include the patch.
> > 
> > All now applied to the 3.14-stable queue, thanks.
> 
> Hello,
> 
> I realized this was not applied to 3.18-stable yet.
> 
> Is there any reason?

I don't maintain the 3.18-stable tree, so there's nothing I can do
there, please be patient and let the other stable maintainers catch up
on things...

thanks,

greg k-h