# CVE-2026-31562: drm/mediatek: dsi: Store driver data before invoking mipi_dsi_host_register

> A null pointer dereference in the Mediatek DSI driver causes a kernel crash during device probe, 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:** 21 Oct 2026
- **Also known as:** BELL-CVE-2026-31562, DEBIAN-CVE-2026-31562, GHSA-6f2j-r97j-f7v5, ROOT-OS-DEBIAN-13-CVE-2026-31562, UBUNTU-CVE-2026-31562

## What is CVE-2026-31562?

CVE-2026-31562 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/mediatek: dsi: Store driver data before invoking mipi_dsi_host_register

The call to mipi_dsi_host_register triggers a callback to mtk_dsi_bind,
which uses dev_get_drvdata to retrieve the mtk_dsi struct, so this
structure needs to be stored inside the driver data before invoking it.

As drvdata is currently uninitialized it leads to a crash when
registering the DSI DRM encoder right after acquiring
the mode_config.idr_mutex, blocking all subsequent DRM operations.

Fixes the following crash during mediatek-drm probe (tested on Xiaomi
Smart Clock x04g):

Unable to handle kernel NULL pointer dereference at virtual address
 0000000000000040
[...]
Modules linked in: mediatek_drm(+) drm_display_helper cec drm_client_lib
 drm_dma_helper drm_kms_helper panel_simple
[...]
Call trace:
 drm_mode_object_add+0x58/0x98 (P)
 __drm_encoder_init+0x48/0x140
 drm_encoder_init+0x6c/0xa0
 drm_simple_encoder_init+0x20/0x34 [drm_kms_helper]
 mtk_dsi_bind+0x34/0x13c [mediatek_drm]
 component_bind_all+0x120/0x280
 mtk_drm_bind+0x284/0x67c [mediatek_drm]
 try_to_bring_up_aggregate_device+0x23c/0x320
 __component_add+0xa4/0x198
 component_add+0x14/0x20
 mtk_dsi_host_attach+0x78/0x100 [mediatek_drm]
 mipi_dsi_attach+0x2c/0x50
 panel_simple_dsi_probe+0x4c/0x9c [panel_simple]
 mipi_dsi_drv_probe+0x1c/0x28
 really_probe+0xc0/0x3dc
 __driver_probe_device+0x80/0x160
 driver_probe_device+0x40/0x120
 __device_attach_driver+0xbc/0x17c
 bus_for_each_drv+0x88/0xf0
 __device_attach+0x9c/0x1cc
 device_initial_probe+0x54/0x60
 bus_probe_device+0x34/0xa0
 device_add+0x5b0/0x800
 mipi_dsi_device_register_full+0xdc/0x16c
 mipi_dsi_host_register+0xc4/0x17c
 mtk_dsi_probe+0x10c/0x260 [mediatek_drm]
 platform_probe+0x5c/0xa4
 really_probe+0xc0/0x3dc
 __driver_probe_device+0x80/0x160
 driver_probe_device+0x40/0x120
 __driver_attach+0xc8/0x1f8
 bus_for_each_dev+0x7c/0xe0
 driver_attach+0x24/0x30
 bus_add_driver+0x11c/0x240
 driver_register+0x68/0x130
 __platform_register_drivers+0x64/0x160
 mtk_drm_init+0x24/0x1000 [mediatek_drm]
 do_one_initcall+0x60/0x1d0
 do_init_module+0x54/0x240
 load_module+0x1838/0x1dc0
 init_module_from_file+0xd8/0xf0
 __arm64_sys_finit_module+0x1b4/0x428
 invoke_syscall.constprop.0+0x48/0xc8
 do_el0_svc+0x3c/0xb8
 el0_svc+0x34/0xe8
 el0t_64_sync_handler+0xa0/0xe4
 el0t_64_sync+0x198/0x19c
Code: 52800022 941004ab 2a0003f3 37f80040 (29005a80)

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-31562?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31562?

Apply the vendor's patch.

## Is CVE-2026-31562 being exploited?

There is no known exploitation of CVE-2026-31562 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-2026-31562 and fix it if it is affected.

What it is: CVE-2026-31562 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-2026-31562 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-2026-31562/ (Markdown: https://insights.sbomify.com/CVE-2026-31562/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31562
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31562
- OSV: https://osv.dev/vulnerability/CVE-2026-31562

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31562/
Summaries are generated and may contain mistakes; the official description above is the record.
