{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-31486",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-31486"
  ],
  "published": "2026-04-22T13:57:42Z",
  "summary": "hwmon: (pmbus/core) Protect regulator operations with mutex",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/core) Protect regulator operations with mutex\n\nThe regulator operations pmbus_regulator_get_voltage(),\npmbus_regulator_set_voltage(), and pmbus_regulator_list_voltage()\naccess PMBus registers and shared data but were not protected by\nthe update_lock mutex. This could lead to race conditions.\n\nHowever, adding mutex protection directly to these functions causes\na deadlock because pmbus_regulator_notify() (which calls\nregulator_notifier_call_chain()) is often called with the mutex\nalready held (e.g., from pmbus_fault_handler()). If a regulator\ncallback then calls one of the now-protected voltage functions,\nit will attempt to acquire the same mutex.\n\nRework pmbus_regulator_notify() to utilize a worker function to\nsend notifications outside of the mutex protection. Events are\nstored as atomics in a per-page bitmask and processed by the worker.\n\nInitialize the worker and its associated data during regulator\nregistration, and ensure it is cancelled on device removal using\ndevm_add_action_or_reset().\n\nWhile at it, remove the unnecessary include of linux/of.h.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-31486"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b26849cffaa7c43355b82e9bef3725e786973a1a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/acf04e2863132f6d9222f71f3a76fb9782cbe061"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4e9d723d9f198b86f6882a84c501ba1f39e8d055"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2c77ae315f3ce9d2c8e1609be74c9358c1fe4e07"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/754bd2b4a084b90b5e7b630e1f423061a9b9b761"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T13:16:28Z"
  }
}