CVE-2025-22009

In the Linux kernel, the following vulnerability has been resolved:

regulator: dummy: force synchronous probing

Sometimes I get a NULL pointer dereference at boot time in kobject_get()
with the following call stack:

anatop_regulator_probe()
 devm_regulator_register()
  regulator_register()
   regulator_resolve_supply()
    kobject_get()

By placing some extra BUG_ON() statements I could verify that this is
raised because probing of the 'dummy' regulator driver is not completed
('dummy_regulator_rdev' is still NULL).

In the JTAG debugger I can see that dummy_regulator_probe() and
anatop_regulator_probe() can be run by different kernel threads
(kworker/u4:*).  I haven't further investigated whether this can be
changed or if there are other possibilities to force synchronization
between these two probe routines.  On the other hand I don't expect much
boot time penalty by probing the 'dummy' regulator synchronously.