{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80660",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-80660"
  ],
  "published": "2026-08-28T06:50:33Z",
  "summary": "hwmon: (occ) unregister sysfs devices outside occ lock",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (occ) unregister sysfs devices outside occ lock\n\nocc_active(false) and occ_shutdown() unregister sysfs-backed devices while\nocc->lock is held.  hwmon_device_unregister() and sysfs_remove_group() can\nwait for active sysfs callbacks to drain, and those callbacks can enter the\nOCC update path and try to take occ->lock again.  That gives the unregister\npaths the lock ordering occ->lock -> sysfs callback drain, while a callback\nhas the opposite edge sysfs callback -> occ->lock.\n\nThis issue was found by our static analysis tool and then manually\nreviewed against the current tree.\n\nThe grounded PoC kept the real unregister and callback carrier:\n\n  occ_shutdown()\n  hwmon_device_unregister()\n  occ_show_temp_1()\n  occ_update_response()\n\nLockdep reported the circular dependency with occ_shutdown() already\nholding the OCC mutex and hwmon_device_unregister() waiting on the sysfs\nside:\n\n  WARNING: possible circular locking dependency detected\n  ... (sysfs_lock) ... at: hwmon_device_unregister+0x12/0x30 [vuln_msv]\n  ... (&test_occ.lock) ... at: occ_shutdown.constprop.0+0xe/0x40 [vuln_msv]\n  occ_update_response.isra.0+0xb/0x20 [vuln_msv]\n  occ_show_temp_1.constprop.0.isra.0+0x23/0x40 [vuln_msv]\n  *** DEADLOCK ***\n\nSerialize hwmon registration and removal with a separate hwmon_lock.\nUnder that lock, detach occ->hwmon and update occ->active while occ->lock\nis held so concurrent OCC state changes still see a stable state, then\ndrop occ->lock before calling hwmon_device_unregister().  Remove the\ndriver sysfs group before taking occ->lock in occ_shutdown(), so draining\nthe driver attributes cannot wait while the OCC mutex is held.  Also make\nOCC update callbacks return -ENODEV after deactivation, so callbacks that\nalready passed sysfs active protection do not poll the hardware after\nteardown has detached the hwmon device.",
  "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": "6.1.178",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80660"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2a4c80ff3571498ec6a916273304b6650026b1b0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e7fd81e9fb1fe476d2131fec66c1138457810ed4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2092952f22a7da98e76e84139ae202b1fc7ba899"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f0aad157576da199c146c1bb266442befa7912ca"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7ee43ec8e6774774abbe9dc3027225e01bc964a5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e31408734332b8cc611342cdaaab6ba492180156"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-28T06:50:33Z"
  }
}