GHSA-WHH2-H34G-XX55

Vulnerability from github – Published: 2026-01-05 12:30 – Updated: 2026-01-19 15:30
VLAI?
Details

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.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2025-68758"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-01-05T10:15:56Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbacklight: led-bl: Add devlink to supplier LEDs\n\nLED Backlight is a consumer of one or multiple LED class devices, but\ndevlink is currently unable to create correct supplier-producer links when\nthe supplier is a class device. It creates instead a link where the\nsupplier is the parent of the expected device.\n\nOne consequence is that removal order is not correctly enforced.\n\nIssues happen for example with the following sections in a device tree\noverlay:\n\n    // An LED driver chip\n    pca9632@62 {\n        compatible = \"nxp,pca9632\";\n        reg = \u003c0x62\u003e;\n\n\t// ...\n\n        addon_led_pwm: led-pwm@3 {\n            reg = \u003c3\u003e;\n            label = \"addon:led:pwm\";\n        };\n    };\n\n    backlight-addon {\n        compatible = \"led-backlight\";\n        leds = \u003c\u0026addon_led_pwm\u003e;\n        brightness-levels = \u003c255\u003e;\n        default-brightness-level = \u003c255\u003e;\n    };\n\nIn this example, the devlink should be created between the backlight-addon\n(consumer) and the pca9632@62 (supplier). Instead it is created between the\nbacklight-addon (consumer) and the parent of the pca9632@62, which is\ntypically the I2C bus adapter.\n\nOn removal of the above overlay, the LED driver can be removed before the\nbacklight device, resulting in:\n\n    Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010\n    ...\n    Call trace:\n     led_put+0xe0/0x140\n     devm_led_release+0x6c/0x98\n\nAnother way to reproduce the bug without any device tree overlays is\nunbinding the LED class device (pca9632@62) before unbinding the consumer\n(backlight-addon):\n\n  echo 11-0062 \u003e/sys/bus/i2c/drivers/leds-pca963x/unbind\n  echo ...backlight-dock \u003e/sys/bus/platform/drivers/led-backlight/unbind\n\nFix by adding a devlink between the consuming led-backlight device and the\nsupplying LED device, as other drivers and subsystems do as well.",
  "id": "GHSA-whh2-h34g-xx55",
  "modified": "2026-01-19T15:30:34Z",
  "published": "2026-01-05T12:30:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-68758"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/08c9dc6b0f2c68e5e7c374ac4499e321e435d46c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0e63ea4378489e09eb5e920c8a50c10caacf563a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/30cbe4b642745a9488a0f0d78be43afe69d7555c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/60a24070392ec726ccfe6ad1ca7b0381c8d8f7c9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/64739adf3eef063b8e2c72b7e919eac8c6480bf0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9341d6698f4cfdfc374fb6944158d111ebe16a9d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd01a24b3e52d6777b49c917d841f125fe9eebd0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e06df738a9ad8417f1c4c7cd6992cda320e9e7ca"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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