CVE-2024-44969

What it actually does

In s390 SCLP Store Data operations, failure to halt an interrupted operation can allow later hardware/firmware writes into buffers that were released, creating a use-after-free condition mitigated by leaking the buffers instead.

Why it matters to the business

Rare hardware or firmware malfunctions on IBM Z systems may cause limited memory leaks and potential system instability, with low immediate operational risk but added maintenance overhead for kernel updates.

How an attack unfolds

An attacker with local access would need to trigger an interrupt during an SCLP Store Data operation while inducing a halt failure through hardware or firmware manipulation; no widespread exploitation is observed given the architecture-specific nature and low EPSS.

How to fix it

Update the Linux kernel to the fixed commit 7a7e60ed23d471a07dbbe72565d2992ee8244bbe or later stable versions containing the s390/sclp buffer release prevention change.

How to confirm the fix worked

Confirm kernel source contains the patch preventing buffer release on SCLP halt failure; verify no related memory leaks under simulated interrupt conditions on s390 hardware.

Typical attack path

1. Obtain local code execution on s390 Linux system
2. Trigger Store Data SCLP operation
3. Interrupt the waiting task
4. Force halt attempt to fail via hardware/firmware conditions
5. Observe subsequent writes to freed buffers or memory leak

How to detect it

Examine kernel logs for SCLP operation failures or buffer-related warnings on s390; correlate with interrupt handling around Store Data operations; no public exploitation artifacts known.

What your security team should do

• Prioritize kernel updates for s390 systems within standard patch cycles
• Monitor for any s390 SCLP-related stability issues post-update
• Review hardware/firmware health on affected IBM Z platforms