From: Sudeep Holla <sudeep.holla@arm.com> stable inclusion from stable-5.10.57 commit 93ef561406a712b32e9a2203b406877081fa0df7 bugzilla: 176179 https://gitee.com/openeuler/kernel/issues/I4DZ64 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@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 1377ec76a45d..def8a84d1611 100644 --- a/drivers/firmware/arm_scmi/bus.c +++ b/drivers/firmware/arm_scmi/bus.c @@ -113,6 +113,9 @@ 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; -- 2.20.1