CVE-2026-99004 Linux CVE debrief

Who should care

Linux kernel maintainers, administrators, and security teams responsible for managing Linux kernel deployments should assess exposure and verify patch deployment to mitigate potential out-of-memory conditions.

Why it matters

Linux kernel vulnerability in drm/imagination affects memory preallocation, potentially leading to out-of-memory panics; assess exposure and verify patch deployment

• Verify patch deployment to prevent out-of-memory panics
• Assess exposure of Linux kernel deployments to CVE-2026-99004
• Monitor system memory usage for potential out-of-memory conditions

Technical summary

The Linux kernel vulnerability CVE-2026-99004 affects drm/imagination, causing improper sizing of page table preallocation by device address. This could lead to out-of-memory panics when a mapping crosses a page table boundary, causing the driver to preallocate a huge number of MMU pages. The vulnerability involves a bug in the previous implementation, where the difference between start and end indices could underflow when a mapping crossed a page table boundary. This would lead to the driver preallocating a huge number of MMU pages, exhausting system memory and triggering an out of memory panic.

Defensive priority

medium

Recommended defensive actions

• Assess exposure of Linux kernel deployments to CVE-2026-99004
• Verify patch deployment for affected Linux kernel versions
• Monitor system memory usage for potential out-of-memory conditions
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on a Linux kernel vulnerability affecting drm/imagination. The vulnerability involves improper sizing of page table preallocation by device address, potentially leading to out-of-memory panics. The source item includes references to specific commits addressing the issue.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.