---
id: "CVE-2026-99004"
kind: "vulnerability"
aliases: ["CVE-2026-99004"]
title: "Linux DRM imagination driver: page table sizing bug causes memory exhaustion"
severity: "unknown"
cvss: null
epss: 0.00209
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["arm", "embedded", "imagination-gpu", "linux-kernel", "runtime"]
not_affected_if: ["driver-not-loaded", "no-imagination-gpu"]
published_at: "2026-10-23T13:17:22+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T12:38:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99004", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-99004", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# Linux DRM imagination driver: page table sizing bug causes memory exhaustion

The Linux kernel's Imagination GPU (drm/imagination) driver sizes its MMU page table preallocation incorrectly when a mapping crosses a page table boundary. The arithmetic can underflow and preallocate a huge number of MMU pages, exhausting system memory and causing an out-of-memory panic.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether the running kernel includes the drm/imagination fix referenced by commit 0a8224058a58 and this follow-up, for example with `uname -r` against your distribution's advisory
- Check whether the Imagination GPU driver is loaded with `lsmod | grep pvr`
- Check the affected kernel version range in the NVD entry (https://nvd.nist.gov/vuln/detail/CVE-2026-99004): unknown

## Fix

- Update the Linux kernel to a release that includes the drm/imagination page table sizing fix, version unknown from the sources
- Until patched, unload the pvr driver where it is not needed: unknown

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99004
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-99004

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

drm/imagination: Size page table preallocation by device address

Commit 0a8224058a58 ("drm/imagination: Fix page count for page table for
map() interface") passed the device address to
pvr_mmu_op_context_create(), but the preallocation is still sized from
device_addr + sgt_offset with an exclusive end. The offset into the
object's pages has no place in a device-virtual range, and the exclusive
end allocates one table too many when the range ends on a table
boundary.

Count the tables from device_addr and the inclusive end of the range.

The new calculation does not take page table indices into account. This
fixes another issue with 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.

[Alessio: add paragraph to point out OOM bug being fixed, cc stable]

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_