CVE-2022-48732

What it actually does

Off-by-one error in BIOS boundary checking for init scripts in the nouveau DRM driver rejects access to the final byte of the image, causing initialization failure on specific hardware.

Why it matters to the business

Driver initialization fails on legacy PowerPC Apple eMac systems with GeForce 2 MX GPUs under OpenFirmware, resulting in no working console; published 849 days ago with stable low EPSS of 0.00235 and not used in ransomware or KEV.

How an attack unfolds

The flaw is triggered automatically during nouveau driver load when the BIOS image provided by OpenFirmware lacks trailing padding bytes; no active threat actor exploitation is known despite one mismatched actor reference.

How to fix it

Update the Linux kernel to commit d4b746e60fd8eaa8016e144223abe91158edcdad or later stable release containing the bounds check fix.

How to confirm the fix worked

Verify nouveau driver initializes successfully on the affected eMac hardware and confirm the kernel tree contains commit d4b746e60fd8eaa8016e144223abe91158edcdad.

Typical attack path

1. Load nouveau DRM driver on affected OpenFirmware PowerPC hardware
2. Parse truncated BIOS init script image lacking end padding
3. Off-by-one bounds check rejects final valid byte
4. Driver initialization aborts leaving no console

How to detect it

Review kernel boot logs for nouveau driver initialization failures mentioning BIOS script parsing on PowerPC systems; no post-exploitation artifacts exist because the issue prevents driver startup.

What your security team should do

• Apply the referenced kernel commit or equivalent stable update on all systems using the nouveau driver
• Test graphics initialization on legacy PowerPC OpenFirmware hardware before broad rollout
• Monitor kernel logs for nouveau BIOS parsing errors on older Apple hardware