CVE-2023-52853

What it actually does

Duplicate initialization of a delayed workqueue in the cp2112 HID driver during repeated IRQ startup calls leads to warnings in set_work_data and a rare NULL pointer dereference in process_one_work within the workqueue subsystem.

Why it matters to the business

Systems using the affected cp2112 driver may experience occasional kernel warnings or crashes during IRQ handling, resulting in device instability or reduced availability for hardware relying on this GPIO/IRQ functionality.

How an attack unfolds

An attacker with local access triggers multiple IRQ startup sequences on the cp2112 device after the initial probe, causing the workqueue to be re-initialized and hitting the race condition that leads to the NULL dereference during work processing.

How to fix it

Update the Linux kernel to a version containing commit df0daac2709473531d6a3472997cc65301ac06d6 or the equivalent cp2112 probe initialization change; for azure-rtos/guix apply commit 354445beacb6f69042c4721cae98d24fbb8651d4. Rebuild and deploy the updated kernel or driver module.

How to confirm the fix worked

Confirm the cp2112 driver source no longer contains INIT_DELAYED_WORK inside cp2112_gpio_irq_startup and that initialization occurs only in the probe routine; test by exercising repeated IRQ startup sequences and verifying absence of workqueue warnings or crashes.

Typical attack path

1. Obtain local access to a system with the cp2112 driver loaded
2. Trigger repeated cp2112_gpio_irq_startup calls via user-space IRQ requests or device interaction
3. Force the duplicate INIT_DELAYED_WORK path before the probe-time initialization fix
4. Observe workqueue processing hitting the uninitialized state leading to NULL dereference

How to detect it

Search kernel logs for repeated workqueue warnings mentioning set_work_data or process_one_work in conjunction with cp2112 device activity; examine dmesg or syslog for NULL dereference traces tied to the hid-cp2112 module.

What your security team should do

• Prioritize kernel updates on systems exposing the cp2112 HID driver
• Monitor workqueue-related kernel logs for set_work_data warnings as an indicator of exposure
• Restrict unprivileged local access on affected embedded or IoT devices until patched