# CVE-2026-31540: drm/i915/gt: Check set_default_submission() before deferencing

> A missing null check in the i915 graphics driver causes a kernel crash during suspend if firmware is missing, 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:** 24 Apr 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-31540, DEBIAN-CVE-2026-31540, GHSA-wvx2-mp64-q5wj, ROOT-OS-DEBIAN-11-CVE-2026-31540, ROOT-OS-DEBIAN-12-CVE-2026-31540, ROOT-OS-UBUNTU-2204-CVE-2026-31540, ROOT-OS-UBUNTU-2404-CVE-2026-31540, UBUNTU-CVE-2026-31540

## What is CVE-2026-31540?

CVE-2026-31540 is a medium-severity vulnerability in Linux kernel, published on 24 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/i915/gt: Check set_default_submission() before deferencing

When the i915 driver firmware binaries are not present, the
set_default_submission pointer is not set. This pointer is
dereferenced during suspend anyways.

Add a check to make sure it is set before dereferencing.

[   23.289926] PM: suspend entry (deep)
[   23.293558] Filesystems sync: 0.000 seconds
[   23.298010] Freezing user space processes
[   23.302771] Freezing user space processes completed (elapsed 0.000 seconds)
[   23.309766] OOM killer disabled.
[   23.313027] Freezing remaining freezable tasks
[   23.318540] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[   23.342038] serial 00:05: disabled
[   23.345719] serial 00:02: disabled
[   23.349342] serial 00:01: disabled
[   23.353782] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[   23.358993] sd 1:0:0:0: [sdb] Synchronizing SCSI cache
[   23.361635] ata1.00: Entering standby power mode
[   23.368863] ata2.00: Entering standby power mode
[   23.445187] BUG: kernel NULL pointer dereference, address: 0000000000000000
[   23.452194] #PF: supervisor instruction fetch in kernel mode
[   23.457896] #PF: error_code(0x0010) - not-present page
[   23.463065] PGD 0 P4D 0
[   23.465640] Oops: Oops: 0010 [#1] SMP NOPTI
[   23.469869] CPU: 8 UID: 0 PID: 211 Comm: kworker/u48:18 Tainted: G S      W           6.19.0-rc4-00020-gf0b9d8eb98df #10 PREEMPT(voluntary)
[   23.482512] Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN
[   23.496511] Workqueue: async async_run_entry_fn
[   23.501087] RIP: 0010:0x0
[   23.503755] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[   23.510324] RSP: 0018:ffffb4a60065fca8 EFLAGS: 00010246
[   23.515592] RAX: 0000000000000000 RBX: ffff9f428290e000 RCX: 000000000000000f
[   23.522765] RDX: 0000000000000000 RSI: 0000000000000282 RDI: ffff9f428290e000
[   23.529937] RBP: ffff9f4282907070 R08: ffff9f4281130428 R09: 00000000ffffffff
[   23.537111] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9f42829070f8
[   23.544284] R13: ffff9f4282906028 R14: ffff9f4282900000 R15: ffff9f4282906b68
[   23.551457] FS:  0000000000000000(0000) GS:ffff9f466b2cf000(0000) knlGS:0000000000000000
[   23.559588] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   23.565365] CR2: ffffffffffffffd6 CR3: 000000031c230001 CR4: 0000000000f70ef0
[   23.572539] PKRU: 55555554
[   23.575281] Call Trace:
[   23.577770]  <TASK>
[   23.579905]  intel_engines_reset_default_submission+0x42/0x60
[   23.585695]  __intel_gt_unset_wedged+0x191/0x200
[   23.590360]  intel_gt_unset_wedged+0x20/0x40
[   23.594675]  gt_sanitize+0x15e/0x170
[   23.598290]  i915_gem_suspend_late+0x6b/0x180
[   23.602692]  i915_drm_suspend_late+0x35/0xf0
[   23.607008]  ? __pfx_pci_pm_suspend_late+0x10/0x10
[   23.611843]  dpm_run_callback+0x78/0x1c0
[   23.615817]  device_suspend_late+0xde/0x2e0
[   23.620037]  async_suspend_late+0x18/0x30
[   23.624082]  async_run_entry_fn+0x25/0xa0
[   23.628129]  process_one_work+0x15b/0x380
[   23.632182]  worker_thread+0x2a5/0x3c0
[   23.635973]  ? __pfx_worker_thread+0x10/0x10
[   23.640279]  kthread+0xf6/0x1f0
[   23.643464]  ? __pfx_kthread+0x10/0x10
[   23.647263]  ? __pfx_kthread+0x10/0x10
[   23.651045]  ret_from_fork+0x131/0x190
[   23.654837]  ? __pfx_kthread+0x10/0x10
[   23.658634]  ret_from_fork_asm+0x1a/0x30
[   23.662597]  </TASK>
[   23.664826] Modules linked in:
[   23.667914] CR2: 0000000000000000
[   23.671271] ------------[ cut here ]------------

(cherry picked from commit daa199abc3d3d1740c9e3a2c3e9216ae5b447cad)

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-31540?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31540?

Apply the vendor's patch.

## Is CVE-2026-31540 being exploited?

There is no known exploitation of CVE-2026-31540 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-2026-31540 and fix it if it is affected.

What it is: CVE-2026-31540 is a medium-severity vulnerability in Linux kernel, published on 24 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-2026-31540 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-2026-31540/ (Markdown: https://insights.sbomify.com/CVE-2026-31540/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31540
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31540
- OSV: https://osv.dev/vulnerability/CVE-2026-31540

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31540/
Summaries are generated and may contain mistakes; the official description above is the record.
