Re: [PATCH v2] s390/vfio-ap: fix memory leak in mdev remove callback

Jason Gunthorpe
2021-05-13T17:25:14Z

On Thu, May 13, 2021 at 10:18:44AM -0400, Tony Krowiak wrote:
>
>
> On 5/12/21 8:41 AM, Jason Gunthorpe wrote:
> > On Mon, May 10, 2021 at 05:48:37PM -0400, Tony Krowiak wrote:
> > > The mdev remove callback for the vfio_ap device driver bails out with
> > > -EBUSY if the mdev is in use by a KVM guest. The intended purpose was
> > > to prevent the mdev from being removed while in use; however, returning a
> > > non-zero rc does not prevent removal. This could result in a memory leak
> > > of the resources allocated when the mdev was created. In addition, the
> > > KVM guest will still have access to the AP devices assigned to the mdev
> > > even though the mdev no longer exists.
> > >
> > > To prevent this scenario, cleanup will be done - including unplugging the
> > > AP adapters, domains and control domains - regardless of whether the mdev
> > > is in use by a KVM guest or not.
> > >
> > > Fixes: 258287c994de ("s390: vfio-ap: implement mediated device open callback")
> > > Cc: stable@vger.kernel.org
> > > Signed-off-by: Tony Krowiak <akrowiak@stny.rr.com>
> > > drivers/s390/crypto/vfio_ap_ops.c | 13 ++-----------
> > > 1 file changed, 2 insertions(+), 11 deletions(-)
> > Can you please ensure this goes to a -rc branch or through Alex's
> > tree?
>
> I'm sorry, I don't know what a -rc branch is nor how to push this
> to Alex's tree, but I'd be happy to do so if you tell me now:)

If Christian takes it for 5.13-rc then that is OK

Otherwise please ask AlexW to take it

Thanks,
Jason