# CVE-2026-31479: drm/xe: always keep track of remap prev/next

> A race condition in the Linux kernel's Xe GPU driver can cause a system crash during 3D workload unwinding, leading to denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 22 Apr 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-31479, DEBIAN-CVE-2026-31479, GHSA-ch6h-82qw-75ww, ROOT-OS-DEBIAN-13-CVE-2026-31479, ROOT-OS-UBUNTU-2404-CVE-2026-31479, UBUNTU-CVE-2026-31479

## What is CVE-2026-31479?

CVE-2026-31479 is a high-severity vulnerability in Linux kernel, published on 22 Apr 2026. 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: always keep track of remap prev/next

During 3D workload, user is reporting hitting:

[  413.361679] WARNING: drivers/gpu/drm/xe/xe_vm.c:1217 at vm_bind_ioctl_ops_unwind+0x1e2/0x2e0 [xe], CPU#7: vkd3d_queue/9925
[  413.361944] CPU: 7 UID: 1000 PID: 9925 Comm: vkd3d_queue Kdump: loaded Not tainted 7.0.0-070000rc3-generic #202603090038 PREEMPT(lazy)
[  413.361949] RIP: 0010:vm_bind_ioctl_ops_unwind+0x1e2/0x2e0 [xe]
[  413.362074] RSP: 0018:ffffd4c25c3df930 EFLAGS: 00010282
[  413.362077] RAX: 0000000000000000 RBX: ffff8f3ee817ed10 RCX: 0000000000000000
[  413.362078] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  413.362079] RBP: ffffd4c25c3df980 R08: 0000000000000000 R09: 0000000000000000
[  413.362081] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8f41fbf99380
[  413.362082] R13: ffff8f3ee817e968 R14: 00000000ffffffef R15: ffff8f43d00bd380
[  413.362083] FS:  00000001040ff6c0(0000) GS:ffff8f4696d89000(0000) knlGS:00000000330b0000
[  413.362085] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[  413.362086] CR2: 00007ddfc4747000 CR3: 00000002e6262005 CR4: 0000000000f72ef0
[  413.362088] PKRU: 55555554
[  413.362089] Call Trace:
[  413.362092]  <TASK>
[  413.362096]  xe_vm_bind_ioctl+0xa9a/0xc60 [xe]

Which seems to hint that the vma we are re-inserting for the ops unwind
is either invalid or overlapping with something already inserted in the
vm. It shouldn't be invalid since this is a re-insertion, so must have
worked before. Leaving the likely culprit as something already placed
where we want to insert the vma.

Following from that, for the case where we do something like a rebind in
the middle of a vma, and one or both mapped ends are already compatible,
we skip doing the rebind of those vma and set next/prev to NULL. As well
as then adjust the original unmap va range, to avoid unmapping the ends.
However, if we trigger the unwind path, we end up with three va, with
the two ends never being removed and the original va range in the middle
still being the shrunken size.

If this occurs, one failure mode is when another unwind op needs to
interact with that range, which can happen with a vector of binds. For
example, if we need to re-insert something in place of the original va.
In this case the va is still the shrunken version, so when removing it
and then doing a re-insert it can overlap with the ends, which were
never removed, triggering a warning like above, plus leaving the vm in a
bad state.

With that, we need two things here:

 1) Stop nuking the prev/next tracking for the skip cases. Instead
    relying on checking for skip prev/next, where needed. That way on the
    unwind path, we now correctly remove both ends.

 2) Undo the unmap va shrinkage, on the unwind path. With the two ends
    now removed the unmap va should expand back to the original size again,
    before re-insertion.

v2:
  - Update the explanation in the commit message, based on an actual IGT of
    triggering this issue, rather than conjecture.
  - Also undo the unmap shrinkage, for the skip case. With the two ends
    now removed, the original unmap va range should expand back to the
    original range.
v3:
  - Track the old start/range separately. vma_size/start() uses the va
    info directly.

(cherry picked from commit aec6969f75afbf4e01fd5fb5850ed3e9c27043ac)

Weakness: CWE-662 (Improper Synchronization)

## Which versions are affected by CVE-2026-31479?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31479?

Apply the vendor's patch.

## Is CVE-2026-31479 being exploited?

There is no known exploitation of CVE-2026-31479 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-2026-31479 and fix it if it is affected.

What it is: CVE-2026-31479 is a high-severity vulnerability in Linux kernel, published on 22 Apr 2026. 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-2026-31479 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-2026-31479/ (Markdown: https://insights.sbomify.com/CVE-2026-31479/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31479
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31479
- OSV: https://osv.dev/vulnerability/CVE-2026-31479

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31479/
Summaries are generated and may contain mistakes; the official description above is the record.
