CVE-2024-26646

What it actually does

The vulnerability allows the Intel Hardware Feedback Interface (HFI) hardware to continue using a stale or invalid memory buffer address after resume from hibernation or deep suspend, resulting in writes to arbitrary kernel memory locations and potential corruption.

Why it matters to the business

Systems may experience unexpected crashes, data corruption, or instability during routine power management operations such as hibernation or suspend on affected Linux kernels, increasing operational risk and potential downtime for servers and workstations.

How an attack unfolds

An attacker with the ability to initiate or influence system suspend/hibernate cycles (typically requiring local access) can trigger the resume path where the HFI hardware retains a pointer to memory allocated by the restore kernel; upon transfer back to the image kernel this pointer becomes invalid, allowing hardware writes that corrupt kernel structures.

How to fix it

Upgrade the Linux kernel to a version containing commit 28f010dc50df0f7987c04112114fcfa7e0803566 or later; the fix adds syscore callbacks that disable HFI before suspend/hibernate and re-enable it on resume.

How to confirm the fix worked

Confirm the running kernel contains commit 28f010dc50df0f7987c04112114fcfa7e0803566 via kernel version string or git log; test suspend/hibernate/resume cycles on representative hardware and monitor for memory corruption indicators such as kernel oops or unexpected panics.

Typical attack path

1. Obtain local execution or user-level access on a target Linux system with Intel HFI enabled.
2. Force or wait for a hibernation or deep suspend event.
3. Allow the restore kernel to allocate a new HFI buffer and program hardware with its address.
4. Trigger resume to the original kernel image whose HFI buffer address is no longer valid.
5. Hardware continues DMA writes into the now-invalid buffer, corrupting memory.

How to detect it

Review kernel logs for HFI-related errors or panics around suspend/resume timestamps; inspect dmesg and journalctl entries mentioning thermal or intel_hfi during power state transitions; no widespread in-the-wild exploitation artifacts are known.

What your security team should do

• Prioritize kernel updates on all Intel-based Linux systems that support hibernation or deep suspend.
• Apply the fix within standard patching windows given low EPSS and absence from KEV.
• Verify that power-management test suites cover HFI-enabled hardware after deployment.