CVE-2024-42093

What it actually does

The flaw causes potential stack overflow in the Linux kernel net/dpaa2 driver by allocating a cpumask variable directly on the stack instead of using cpumask_var APIs when CONFIG_CPUMASK_OFFSTACK=y is set.

Why it matters to the business

Affected Linux systems risk kernel crashes, local privilege escalation, or denial of service, potentially disrupting network services and requiring urgent patching across server fleets.

How an attack unfolds

An attacker with local access triggers the dpaa2 network code path to force stack-based cpumask allocation, overflowing the stack to corrupt memory and achieve code execution or system instability.

How to fix it

Update the Linux kernel to the fixed commit b2262b3be27cee334a2fa175ae3afb53f38fb0b1 or later stable versions incorporating the cpumask_var API changes.

How to confirm the fix worked

Verify the running kernel includes commit b2262b3be27cee334a2fa175ae3afb53f38fb0b1 via git log or kernel version strings; test cpumask allocation paths under CONFIG_CPUMASK_OFFSTACK=y.

Typical attack path

1. Obtain local user access on a vulnerable Linux system
2. Load or trigger net/dpaa2 driver code paths involving cpumask operations
3. Trigger stack overflow via crafted network or device operations
4. Exploit corrupted stack for privilege escalation or denial of service

How to detect it

Review kernel logs for stack overflow warnings or panics in net/dpaa2 paths; inspect audit logs for unusual local process activity involving network devices.

What your security team should do

• Immediately upgrade all affected Linux kernel instances to the fixed commit
• Prioritize systems with CONFIG_CPUMASK_OFFSTACK enabled and dpaa2 networking
• Monitor for local privilege escalation attempts post-patch
• Apply kernel hardening configurations to limit stack usage