[PATCH 4.19 34/91] vfio-ccw: Set pa_nr to 0 if memory allocation fails for pa_iova_pfn

[Greg Kroah-Hartman]

[ Upstream commit c1ab69268d124ebdbb3864580808188ccd3ea355 ]

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 <al...@linux.ibm.com>
Reviewed-by: Eric Farman <far...@linux.ibm.com>
Reviewed-by: Cornelia Huck <coh...@redhat.com>
Message-Id: 
<33a89467ad6369196ae6edf820cbcb1e2d8d050c.1562854091.git.al...@linux.ibm.com>
Signed-off-by: Cornelia Huck <coh...@redhat.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/s390/cio/vfio_ccw_cp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index 70a006ba4d050..4fe06ff7b2c8b 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -89,8 +89,10 @@ static int pfn_array_alloc_pin(struct pfn_array *pa, struct 
device *mdev,
                                  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;
-- 
2.20.1