s390/vfio-ap: fix memory leak in vfio_ap device driver

[ Upstream commit 8f8cf767589f2131ae5d40f3758429095c701c84 ]

The device release callback function invoked to release the matrix device
uses the dev_get_drvdata(device *dev) function to retrieve the
pointer to the vfio_matrix_dev object in order to free its storage. The
problem is, this object is not stored as drvdata with the device; since the
kfree function will accept a NULL pointer, the memory for the
vfio_matrix_dev object is never freed.

Since the device being released is contained within the vfio_matrix_dev
object, the container_of macro will be used to retrieve its pointer.

Fixes: 099e96540ac7 ("s390: vfio-ap: base implementation of VFIO AP device driver")
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Link: https://lore.kernel.org/r/20230320150447.34557-1-akrowiak@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
index 7dc72cb718b0e2866226eefcde6a4832b99cbeb3..22128eb44f7faf426fdd06de353dc25b507453ec 100644 (file)
--- a/drivers/s390/crypto/vfio_ap_drv.c
+++ b/drivers/s390/crypto/vfio_ap_drv.c
@@ -82,8 +82,9 @@ 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);
+       struct ap_matrix_dev *matrix_dev;
 
+       matrix_dev = container_of(dev, struct ap_matrix_dev, device);
        kfree(matrix_dev);
 }