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 <u...@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

Reply via email to