CVE-2024-26817

What it actually does

Potential integer overflow during size calculation for kzalloc in amdkfd driver could result in under-allocation of memory, enabling subsequent memory corruption.

Why it matters to the business

On systems using AMD GPUs with KFD support, local users could trigger kernel memory corruption leading to crashes, data corruption, or privilege escalation; widespread kernel usage increases exposure across servers, workstations, and embedded devices despite low exploitation likelihood.

How an attack unfolds

An attacker with local access crafts input causing multiplication overflow in allocation size before kzalloc, resulting in a smaller buffer than expected that is later written beyond, corrupting adjacent kernel structures in the AMD KFD subsystem.

How to fix it

Update the Linux kernel to a version containing commit e6721ea845fcb93a764a92bd40f1afc0d6c69751 which replaces kzalloc with calloc in amdkfd to prevent the overflow; rebuild and deploy updated kernel packages across all affected systems.

How to confirm the fix worked

Verify kernel source or binary contains the calloc change in amdkfd allocation code; confirm no multiplication precedes the allocation call and test with large size parameters to ensure proper handling.

Typical attack path

1. Obtain local code execution on target Linux system with AMD KFD enabled
2. Trigger amdkfd allocation path with parameters designed to overflow integer multiplication
3. Exploit resulting undersized buffer to corrupt kernel memory
4. Escalate privileges or cause denial of service

How to detect it

Review kernel logs and audit trails for allocation-related warnings or crashes in amdkfd paths; examine core dumps or memory forensics for signs of undersized buffer usage in KFD driver code.

What your security team should do

• Prioritize kernel updates on all AMD GPU systems within standard change windows
• Monitor upstream stable kernel releases for backports of the fix
• Restrict unprivileged local access where possible until patched