CVE-2024-26922

What it actually does

The flaw is an improper input validation issue in the Linux kernel AMDGPU driver that allowed invalid parameters to reach amdgpu_vm_bo_map, amdgpu_vm_bo_replace_map, and amdgpu_vm_bo_clearing_mappings without centralized checks, potentially resulting in incorrect virtual memory mappings or memory safety violations.

Why it matters to the business

Organizations running affected Linux kernels on AMD GPU hardware face elevated risk of system instability, crashes, or kernel-level memory corruption that can disrupt workloads, require unplanned reboots, and increase exposure to local privilege escalation on servers, workstations, and embedded devices using the stable kernel tree.

How an attack unfolds

An attacker with local access supplies crafted parameters to the affected BO mapping functions; absent centralized validation the driver proceeds with invalid mappings that can be abused to corrupt kernel memory structures or trigger use-after-free conditions, enabling privilege escalation or denial of service.

How to fix it

Update the Linux kernel to the commit d4da6b084f1c5625937d49bb6722c5b4aef11b8d or later stable releases that contain the centralized parameter validation for amdgpu_vm_bo_map, replace_map, and clearing_mappings. Rebuild and deploy the updated kernel across all affected AMD GPU systems, then verify the fix is active by confirming the new validation logic is present.

How to confirm the fix worked

Confirm the kernel source contains the centralized validation routine introduced in commit d4da6b084f1c5625937d49bb6722c5b4aef11b8d; test by exercising amdgpu BO mapping ioctls with both valid and deliberately invalid parameters and ensure invalid cases are rejected before mapping occurs.

Typical attack path

1. Obtain local code execution on a system running an affected kernel with AMDGPU support
2. Invoke amdgpu BO mapping ioctls with malformed offset, size, or flags values
3. Trigger the unvalidated code path that performs the mapping operation
4. Leverage resulting kernel memory corruption or mapping errors for privilege escalation or crash

How to detect it

Review kernel logs for unexpected amdgpu VM mapping failures or warnings after the fix date; examine audit logs for unusual ioctl activity targeting amdgpu BO mapping functions; look for post-exploit artifacts such as sudden privilege changes or kernel oops entries referencing amdgpu_vm.

What your security team should do

• Prioritize kernel updates on all AMDGPU-equipped systems within the next maintenance window
• Monitor upstream stable kernel releases for additional backports of the validation fix
• Review local kernel configurations to ensure AMDGPU driver is only enabled where hardware is present
• Add kernel update automation and rollback testing to reduce future exposure windows