[PATCH v2 1/5] dax-device: Prevent registering drivers without probe callback
The bus probe function dax_bus_probe() calls the probe callback without
checking it to be non-NULL. Prevent a NULL pointer exception if a driver
without a probe function is registered by refusing to register this
driver.
Signed-off-by: Uwe Kleine-König <uwe(a)kleine-koenig.org>
---
drivers/dax/bus.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 737b207c9e30..72fc4b9b9ae6 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1392,6 +1392,13 @@ int __dax_driver_register(struct dax_device_driver *dax_drv,
struct device_driver *drv = &dax_drv->drv;
int rc = 0;
+ /*
+ * dax_bus_probe() calls dax_drv->probe() unconditionally.
+ * So better be safe than sorry and ensure it is provided.
+ */
+ if (!dax_drv->probe)
+ return -EINVAL;
+
INIT_LIST_HEAD(&dax_drv->ids);
drv->owner = module;
drv->name = mod_name;
--
2.29.2