CVE-2024-26915

What it actually does

Failure to reset the IH OVERFLOW_CLEAR bit after handling an Interrupt Handler ring buffer overflow in the AMD GPU driver prevents detection of subsequent overflows, allowing repeated buffer overruns to go unnoticed.

Why it matters to the business

Systems using affected AMD GPUs may experience undetected interrupt handling issues that degrade graphics stability or enable stealthy resource exhaustion without triggering alerts or logs.

How an attack unfolds

An attacker triggers repeated IH ring buffer overflows through crafted GPU workloads or DMA operations; because the clear bit is not reset, only the first overflow is recorded, allowing continued abuse without further detection or mitigation responses.

How to fix it

Update the Linux kernel to a version containing commit 9a9d00c23d170d4ef5a1b28e6b69f5c85dd12bc1 or later; rebuild and deploy the updated kernel image across all affected hosts.

How to confirm the fix worked

Verify the running kernel contains the fix commit, inspect drm/amdgpu IH handling code for the OVERFLOW_CLEAR reset, and test overflow scenarios to confirm multiple events are now logged.

Typical attack path

1. Identify a target system with vulnerable AMD GPU driver in the Linux kernel
2. Craft and submit GPU command streams or DMA transfers designed to overflow the IH ring buffer
3. Trigger multiple overflow conditions in quick succession
4. Confirm that only the initial overflow is logged while subsequent events remain undetected
5. Escalate to denial of service or further kernel memory manipulation

How to detect it

Search kernel logs and dmesg output for repeated IH overflow messages after the first occurrence; correlate with GPU workload spikes or DMA activity in audit trails.

What your security team should do

• Prioritize kernel upgrades on all AMD GPU-equipped systems within standard patch windows
• Monitor vendor advisories for backported fixes in distribution kernels
• Review GPU driver logs for historical overflow events as a baseline
• Schedule staged rollouts beginning with high-value or internet-facing workloads