[PATCH 5.4] driver core: bus: Fix double free in driver API bus_register()

[Hagar Hemdan <hagarhem@amazon.com>]

From: Zijun Hu <quic_zijuhu@quicinc.com>

commit bfa54a793ba77ef696755b66f3ac4ed00c7d1248 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
[ hagar : required setting bus->p with NULL instead of priv]
Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
---
 drivers/base/bus.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index f970a40a2f7a..0b0969e64f5c 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -873,6 +873,8 @@ int bus_register(struct bus_type *bus)
 	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;
-- 
2.47.1