---
id: "CVE-2026-99003"
kind: "vulnerability"
aliases: ["CVE-2026-99003"]
title: "Linux kernel Panthor GPU driver: unchecked queue count can crash the system"
severity: "unknown"
cvss: null
epss: 0.00209
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["arm-mali", "embedded", "linux-kernel", "runtime", "single-board-computer"]
not_affected_if: ["no-panthor-driver"]
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-2026-99003", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-99003", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# Linux kernel Panthor GPU driver: unchecked queue count can crash the system

The Panthor DRM driver for Arm Mali GPUs accepts a userspace queue count up to a hardcoded maximum, even when the firmware initialized fewer stream interfaces. Requesting more queues than the firmware reported makes the kernel dereference an uninitialized interface and may crash.

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

## How to check

- unknown

## Fix

- Update the Linux kernel to a release that includes the upstream fix validating queue count against initialized firmware slots (version unknown from sources)

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99003
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-99003

## From the sources

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

drm/panthor: validate userspace queue count against initialized firmware slot count

In panthor_drv.c:panthor_ioctl_group_create(),
the queue count is validated against the hardcoded maximum:

	if (!args->queues.count || args->queues.count > MAX_CS_PER_CSG)
		return -EINVAL;

However, if the firmware reports fewer slots than MAX_CS_PER_CSG,
panthor_fw_init_ifaces() will only initialize that smaller number of
stream interfaces.

If unprivileged userspace requests more queues than the firmware reported
(but no more than MAX_CS_PER_CSG), cs_slot_prog_locked() fetches an
uninitialized stream interface and may crash when dereferencing
cs_iface->input->ringbuf_base.

---

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