CVE-2024-42147

What it actually does

Double release of register mappings during error handling in HiSilicon ZIP debugfs initialization causes a use-after-free when the uninit path executes without a null check on regs.

Why it matters to the business

Low-probability memory corruption or crashes on Linux systems with HiSilicon hardware during device probe; no known active exploitation or ransomware use reduces operational urgency despite the kernel-wide exposure.

How an attack unfolds

An attacker triggers a debugfs initialization failure during the ZIP probe on affected hardware so the error branch releases regs while the normal uninit path also releases them, exercising the use-after-free; listed threat actor campaigns targeting Linux kernel resource issues could attempt local triggering but no public exploit exists.

How to fix it

Update the Linux kernel to commit eda60520cfe3aba9f088c68ebd5bcbca9fc6ac3c or later; apply the null check in the regs uninit routine before releasing.

How to confirm the fix worked

Inspect the regs uninit function for an added null-pointer guard; confirm the probe error path no longer performs duplicate releases; test device initialization with forced debugfs failure.

Typical attack path

1. Gain local access or trigger device probe on HiSilicon ZIP hardware
2. Force debugfs initialization failure during probe
3. Allow both error-branch and normal uninit paths to execute
4. Trigger double-free / use-after-free on regs pointer

How to detect it

Review kernel logs and dmesg for double-free warnings, use-after-free reports, or crashes mentioning hisilicon debugfs or zip probe; correlate with device initialization timestamps.

What your security team should do

• Apply the fixed kernel commit across all affected distributions
• Monitor for kernel oops or slab corruption during hardware probe
• Prioritize updates on systems exposing HiSilicon ZIP devices