# CVE-2025-21644: drm/xe: Fix tlb invalidation when wedging

> A NULL pointer dereference in the Intel Xe GPU driver causes a kernel crash when the GuC firmware fails to load, leading to denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Jan 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-21644, DEBIAN-CVE-2025-21644, GHSA-9hxc-crm7-5f87, UBUNTU-CVE-2025-21644

## What is CVE-2025-21644?

CVE-2025-21644 is a medium-severity vulnerability in Linux kernel, published on 19 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

drm/xe: Fix tlb invalidation when wedging

If GuC fails to load, the driver wedges, but in the process it tries to
do stuff that may not be initialized yet. This moves the
xe_gt_tlb_invalidation_init() to be done earlier: as its own doc says,
it's a software-only initialization and should had been named with the
_early() suffix.

Move it to be called by xe_gt_init_early(), so the locks and seqno are
initialized, avoiding a NULL ptr deref when wedging:

	xe 0000:03:00.0: [drm] *ERROR* GT0: load failed: status: Reset = 0, BootROM = 0x50, UKernel = 0x00, MIA = 0x00, Auth = 0x01
	xe 0000:03:00.0: [drm] *ERROR* GT0: firmware signature verification failed
	xe 0000:03:00.0: [drm] *ERROR* CRITICAL: Xe has declared device 0000:03:00.0 as wedged.
	...
	BUG: kernel NULL pointer dereference, address: 0000000000000000
	#PF: supervisor read access in kernel mode
	#PF: error_code(0x0000) - not-present page
	PGD 0 P4D 0
	Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
	CPU: 9 UID: 0 PID: 3908 Comm: modprobe Tainted: G     U  W          6.13.0-rc4-xe+ #3
	Tainted: [U]=USER, [W]=WARN
	Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-S ADP-S DDR5 UDIMM CRB, BIOS ADLSFWI1.R00.3275.A00.2207010640 07/01/2022
	RIP: 0010:xe_gt_tlb_invalidation_reset+0x75/0x110 [xe]

This can be easily triggered by poking the GuC binary to force a
signature failure. There will still be an extra message,

	xe 0000:03:00.0: [drm] *ERROR* GT0: GuC mmio request 0x4100: no reply 0x4100

but that's better than a NULL ptr deref.

(cherry picked from commit 5001ef3af8f2c972d6fd9c5221a8457556f8bea6)

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-21644?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-21644?

Apply the vendor's patch.

## Is CVE-2025-21644 being exploited?

There is no known exploitation of CVE-2025-21644 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-21644 and fix it if it is affected.

What it is: CVE-2025-21644 is a medium-severity vulnerability in Linux kernel, published on 19 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-21644 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-21644/ (Markdown: https://insights.sbomify.com/CVE-2025-21644/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21644
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21644
- OSV: https://osv.dev/vulnerability/CVE-2025-21644

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21644/
Summaries are generated and may contain mistakes; the official description above is the record.