s390/ccwgroup: require at least one ccw device
ccwgroup_create_dev() derives the gdev's device name from gdev->cdev[0],
so make sure that this reference is valid.
For robustness only, all current ccwgroup drivers get this right.
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index bfec148..5535312 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -323,6 +323,9 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv,
struct ccw_dev_id dev_id;
int rc, i;
+ if (num_devices < 1)
+ return -EINVAL;
+
gdev = kzalloc(sizeof(*gdev) + num_devices * sizeof(gdev->cdev[0]),
GFP_KERNEL);
if (!gdev)
@@ -375,7 +378,7 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv,
goto error;
}
/* Check if the devices are bound to the required ccw driver. */
- if (gdev->count && gdrv && gdrv->ccw_driver &&
+ if (gdrv && gdrv->ccw_driver &&
gdev->cdev[0]->drv != gdrv->ccw_driver) {
rc = -EINVAL;
goto error;
