RE: [PATCH 1/3] Drivers: hv: balloon: don't crash when memory is added in non-sorted order

From: KY Srinivasan
Date: Sat Apr 30 2016 - 17:38:54 EST




> -----Original Message-----
> From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
> Sent: Saturday, April 30, 2016 2:03 PM
> To: KY Srinivasan <kys@xxxxxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx;
> olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; vkuznets@xxxxxxxxxx;
> jasowang@xxxxxxxxxx
> Subject: Re: [PATCH 1/3] Drivers: hv: balloon: don't crash when memory is
> added in non-sorted order
>
> On Fri, Apr 29, 2016 at 11:45:17AM -0700, K. Y. Srinivasan wrote:
> > From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> >
> > When we iterate through all HA regions in handle_pg_range() we have an
> > assumption that all these regions are sorted in the list and the
> > 'start_pfn >= has->end_pfn' check is enough to find the proper region.
> > Unfortunately it's not the case with WS2016 where host can hot-add
> regions
> > in a different order. We end up modifying the wrong HA region and
> crashing
> > later on pages online. Modify the check to make sure we found the region
> > we were searching for while iterating. Fix the same check in pfn_covered()
> > as well.
> >
> > Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> > ---
> > drivers/hv/hv_balloon.c | 4 ++--
> > 1 files changed, 2 insertions(+), 2 deletions(-)
>
> I only received patch 1/3 here, what happened to the other 2?
>
> Can you resend the whole series?

Will do.

Thanks,

K. Y
>
> thanks,
>
> greg k-h