driver core: bus: Fix double free in driver API bus_register()

commit bfa54a793b upstream.

For bus_register(), any error which happens after kset_register() will
cause that @priv are freed twice, fixed by setting @priv with NULL after
the first free.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240727-bus_register_fix-v1-1-fed8dd0dba7a@quicinc.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Brennan : Backport requires bus->p = NULL instead of priv = NULL ]
Signed-off-by: Brennan Lamoreaux <brennan.lamoreaux@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/bus.c

@@ -853,6 +853,8 @@ bus_devices_fail:
 	bus_remove_file(bus, &bus_attr_uevent);
 bus_uevent_fail:
 	kset_unregister(&bus->p->subsys);
+	/* Above kset_unregister() will kfree @bus->p */
+	bus->p = NULL;
 out:
 	kfree(bus->p);
 	bus->p = NULL;