diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2023-02-21 15:53:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-02-25 12:51:21 +0300 |
| commit | e8b812b3e515742a4faaf2e4722bdc5755b98f56 (patch) | |
| tree | d06bc4ac8f2c4d3e8f3883573f61e2629194265e /drivers/base | |
| parent | a93e884edf61f9debc9ca61ef9e545f0394ab666 (diff) | |
| download | linux-e8b812b3e515742a4faaf2e4722bdc5755b98f56.tar.xz | |
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 <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/0a92979f6e790737544638e8a4c19b0564e660a2.1676983596.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/bus.c | 2 |
1 files changed, 1 insertions, 1 deletions
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); |