vfio-ccw: Set pa_nr to 0 if memory allocation fails for pa_iova_pfn

So we don't call try to call vfio_unpin_pages() incorrectly.

Fixes: 0a19e61e6d4c ("vfio: ccw: introduce channel program interfaces")
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <33a89467ad6369196ae6edf820cbcb1e2d8d050c.1562854091.git.alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index e4e8724eddaac90720fe3833127123e472c5a1a0..3645d1720c4b572666ca80940308a7ef53e6c866 100644 (file)
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -72,8 +72,10 @@ static int pfn_array_alloc(struct pfn_array *pa, u64 iova, unsigned int len)
                                  sizeof(*pa->pa_iova_pfn) +
                                  sizeof(*pa->pa_pfn),
                                  GFP_KERNEL);
-       if (unlikely(!pa->pa_iova_pfn))
+       if (unlikely(!pa->pa_iova_pfn)) {
+               pa->pa_nr = 0;
                return -ENOMEM;
+       }
        pa->pa_pfn = pa->pa_iova_pfn + pa->pa_nr;
 
        pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;