On 6/18/21 2:23 PM, Jason Gunthorpe wrote:
On Fri, Jun 18, 2021 at 02:11:23PM -0400, Tony Krowiak wrote:
On 6/18/21 1:12 PM, Jason J. Herne wrote:
vfio_ap_matrix_dev_release is shadowing the global matrix_dev with a NULL
pointer. Driver data for the matrix device is never set and so
dev_get_drvdata() always returns NULL. When release is called we end up
not freeing matrix_dev. The fix is to remove the shadow variable and get
the correct pointer from the device using container_of. We'll also NULL
the global to prevent any future use.
Signed-off-by: Jason J. Herne <jjherne@xxxxxxxxxxxxx>
drivers/s390/crypto/vfio_ap_drv.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
index 7dc72cb718b0..40e66cb363d1 100644
+++ b/drivers/s390/crypto/vfio_ap_drv.c
@@ -82,9 +82,8 @@ static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
static void vfio_ap_matrix_dev_release(struct device *dev)
{
- struct ap_matrix_dev *matrix_dev = dev_get_drvdata(dev);
-
- kfree(matrix_dev);
+ kfree(container_of(dev, struct ap_matrix_dev, device));
I suppose if we're not going to assume that the release is being
called to free the global matrix_dev, then if you are going to
retrieve it using container_of(), then maybe we should verify
the retrieved pointer is the same as the global matrix_dev?
That seems like overkill to me
After thinking about it, it's probably more than overkill as I
assume the container_of() function would fail if dev was
not contained in matrix_mdev:
Reviewed-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Jason
