# CVE-2025-68758: backlight: led-bl: Add devlink to supplier LEDs

> A local attacker with high privileges can trigger a kernel NULL pointer dereference by unbinding LED devices in a specific order, causing a system crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Jan 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-68758, DEBIAN-CVE-2025-68758, GHSA-whh2-h34g-xx55, ROOT-OS-DEBIAN-11-CVE-2025-68758, ROOT-OS-DEBIAN-12-CVE-2025-68758, ROOT-OS-UBUNTU-2204-CVE-2025-68758, ROOT-OS-UBUNTU-2404-CVE-2025-68758, UBUNTU-CVE-2025-68758

## What is CVE-2025-68758?

CVE-2025-68758 is a vulnerability in Linux, published on 5 Jan 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:

backlight: led-bl: Add devlink to supplier LEDs

LED Backlight is a consumer of one or multiple LED class devices, but
devlink is currently unable to create correct supplier-producer links when
the supplier is a class device. It creates instead a link where the
supplier is the parent of the expected device.

One consequence is that removal order is not correctly enforced.

Issues happen for example with the following sections in a device tree
overlay:

    // An LED driver chip
    pca9632@62 {
        compatible = "nxp,pca9632";
        reg = <0x62>;

	// ...

        addon_led_pwm: led-pwm@3 {
            reg = <3>;
            label = "addon:led:pwm";
        };
    };

    backlight-addon {
        compatible = "led-backlight";
        leds = <&addon_led_pwm>;
        brightness-levels = <255>;
        default-brightness-level = <255>;
    };

In this example, the devlink should be created between the backlight-addon
(consumer) and the pca9632@62 (supplier). Instead it is created between the
backlight-addon (consumer) and the parent of the pca9632@62, which is
typically the I2C bus adapter.

On removal of the above overlay, the LED driver can be removed before the
backlight device, resulting in:

    Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
    ...
    Call trace:
     led_put+0xe0/0x140
     devm_led_release+0x6c/0x98

Another way to reproduce the bug without any device tree overlays is
unbinding the LED class device (pca9632@62) before unbinding the consumer
(backlight-addon):

  echo 11-0062 >/sys/bus/i2c/drivers/leds-pca963x/unbind
  echo ...backlight-dock >/sys/bus/platform/drivers/led-backlight/unbind

Fix by adding a devlink between the consuming led-backlight device and the
supplying LED device, as other drivers and subsystems do as well.

## Which versions are affected by CVE-2025-68758?


## How do I fix CVE-2025-68758?

Apply the vendor's patch.

## Is CVE-2025-68758 being exploited?

There is no known exploitation of CVE-2025-68758 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68758 and fix it if it is affected.

What it is: CVE-2025-68758 is a vulnerability in Linux, published on 5 Jan 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-2025-68758 in the wild and no public exploit code.

Affected product: Linux. 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-2025-68758/ (Markdown: https://insights.sbomify.com/CVE-2025-68758/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68758
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68758
- OSV: https://osv.dev/vulnerability/CVE-2025-68758

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68758/
Summaries are generated and may contain mistakes; the official description above is the record.