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 havent 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 dont expect much boot time penalty by probing the dummy regulator synchronously.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/5ade367b56c3947c990598df92395ce737bee872
• https://git.kernel.org/stable/c/8619909b38eeebd3e60910158d7d68441fc954e9
• https://git.kernel.org/stable/c/d3b83a1442a09b145006eb4294b1a963c5345c9c
• https://git.kernel.org/stable/c/e26f24ca4fb940b15e092796c5993142a2558bd9