From e8b812b3e515742a4faaf2e4722bdc5755b98f56 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 21 Feb 2023 13:53:51 +0100 Subject: driver core: bus: Handle early calls to bus_to_subsys() When calling soc_device_match() from early_initcall(), bus_kset is still NULL, causing a crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000028 ... Call trace: __lock_acquire+0x530/0x20f0 lock_acquire.part.0+0xc8/0x210 lock_acquire+0x64/0x80 _raw_spin_lock+0x4c/0x60 bus_to_subsys+0x24/0xac bus_for_each_dev+0x30/0xcc soc_device_match+0x4c/0xe0 r8a7795_sysc_init+0x18/0x60 rcar_sysc_pd_init+0xb0/0x33c do_one_initcall+0x128/0x2bc Before, bus_for_each_dev() handled this gracefully by checking that the back-pointer to the private structure was valid. Fix this by adding a NULL check for bus_kset to bus_to_subsys(). Fixes: 83b9148df2c95e23 ("driver core: bus: bus iterator cleanups") Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/0a92979f6e790737544638e8a4c19b0564e660a2.1676983596.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index cfe8615d5106..dd4b82d7510f 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -62,7 +62,7 @@ static struct subsys_private *bus_to_subsys(const struct bus_type *bus) struct subsys_private *sp = NULL; struct kobject *kobj; - if (!bus) + if (!bus || !bus_kset) return NULL; spin_lock(&bus_kset->list_lock); -- cgit v1.2.3