From: Sudeep Holla sudeep.holla@arm.com
stable inclusion from linux-4.19.202 commit 193b1b15a4bd58736258e308ee26de9947649cb3
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commit 5e469dac326555d2038d199a6329458cc82a34e5 upstream.
The bus probe callback calls the driver callback without further checking. Better be safe than sorry and refuse registration of a driver without a probe function to prevent a NULL pointer exception.
Link: https://lore.kernel.org/r/20210624095059.4010157-2-sudeep.holla@arm.com Fixes: 933c504424a2 ("firmware: arm_scmi: add scmi protocol bus to enumerate protocol devices") Reported-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de Tested-by: Cristian Marussi cristian.marussi@arm.com Reviewed-by: Cristian Marussi cristian.marussi@arm.com Acked-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de Signed-off-by: Sudeep Holla sudeep.holla@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/firmware/arm_scmi/bus.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c index 7a30952b463d5..66d445b14e513 100644 --- a/drivers/firmware/arm_scmi/bus.c +++ b/drivers/firmware/arm_scmi/bus.c @@ -100,6 +100,9 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner, { int retval;
+ if (!driver->probe) + return -EINVAL; + driver->driver.bus = &scmi_bus_type; driver->driver.name = driver->name; driver->driver.owner = owner;