# CVE-2025-21880: drm/xe/userptr: fix EFAULT handling

> A flaw in the Linux kernel's Xe GPU driver causes a kernel warning and potential system instability when handling user pointer faults during rebind operations.

- **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:** 27 Mar 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-21880, DEBIAN-CVE-2025-21880, GHSA-6fj2-q3x5-whq9, ROOT-OS-UBUNTU-2404-CVE-2025-21880, UBUNTU-CVE-2025-21880

## What is CVE-2025-21880?

CVE-2025-21880 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Mar 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/userptr: fix EFAULT handling

Currently we treat EFAULT from hmm_range_fault() as a non-fatal error
when called from xe_vm_userptr_pin() with the idea that we want to avoid
killing the entire vm and chucking an error, under the assumption that
the user just did an unmap or something, and has no intention of
actually touching that memory from the GPU.  At this point we have
already zapped the PTEs so any access should generate a page fault, and
if the pin fails there also it will then become fatal.

However it looks like it's possible for the userptr vma to still be on
the rebind list in preempt_rebind_work_func(), if we had to retry the
pin again due to something happening in the caller before we did the
rebind step, but in the meantime needing to re-validate the userptr and
this time hitting the EFAULT.

This explains an internal user report of hitting:

[  191.738349] WARNING: CPU: 1 PID: 157 at drivers/gpu/drm/xe/xe_res_cursor.h:158 xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[  191.738551] Workqueue: xe-ordered-wq preempt_rebind_work_func [xe]
[  191.738616] RIP: 0010:xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[  191.738690] Call Trace:
[  191.738692]  <TASK>
[  191.738694]  ? show_regs+0x69/0x80
[  191.738698]  ? __warn+0x93/0x1a0
[  191.738703]  ? xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[  191.738759]  ? report_bug+0x18f/0x1a0
[  191.738764]  ? handle_bug+0x63/0xa0
[  191.738767]  ? exc_invalid_op+0x19/0x70
[  191.738770]  ? asm_exc_invalid_op+0x1b/0x20
[  191.738777]  ? xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[  191.738834]  ? ret_from_fork_asm+0x1a/0x30
[  191.738849]  bind_op_prepare+0x105/0x7b0 [xe]
[  191.738906]  ? dma_resv_reserve_fences+0x301/0x380
[  191.738912]  xe_pt_update_ops_prepare+0x28c/0x4b0 [xe]
[  191.738966]  ? kmemleak_alloc+0x4b/0x80
[  191.738973]  ops_execute+0x188/0x9d0 [xe]
[  191.739036]  xe_vm_rebind+0x4ce/0x5a0 [xe]
[  191.739098]  ? trace_hardirqs_on+0x4d/0x60
[  191.739112]  preempt_rebind_work_func+0x76f/0xd00 [xe]

Followed by NPD, when running some workload, since the sg was never
actually populated but the vma is still marked for rebind when it should
be skipped for this special EFAULT case. This is confirmed to fix the
user report.

v2 (MattB):
 - Move earlier.
v3 (MattB):
 - Update the commit message to make it clear that this indeed fixes the
   issue.

(cherry picked from commit 6b93cb98910c826c2e2004942f8b060311e43618)

## Which versions are affected by CVE-2025-21880?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-21880?

Apply the vendor's patch.

## Is CVE-2025-21880 being exploited?

There is no known exploitation of CVE-2025-21880 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-2025-21880 and fix it if it is affected.

What it is: CVE-2025-21880 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Mar 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-2025-21880 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-2025-21880/ (Markdown: https://insights.sbomify.com/CVE-2025-21880/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21880
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21880
- OSV: https://osv.dev/vulnerability/CVE-2025-21880

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21880/
Summaries are generated and may contain mistakes; the official description above is the record.
