FKIE_CVE-2026-80660

Vulnerability from fkie_nvd - Published: 2026-08-28 08:16 - Updated: 2026-08-28 08:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: hwmon: (occ) unregister sysfs devices outside occ lock occ_active(false) and occ_shutdown() unregister sysfs-backed devices while occ->lock is held. hwmon_device_unregister() and sysfs_remove_group() can wait for active sysfs callbacks to drain, and those callbacks can enter the OCC update path and try to take occ->lock again. That gives the unregister paths the lock ordering occ->lock -> sysfs callback drain, while a callback has the opposite edge sysfs callback -> occ->lock. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the real unregister and callback carrier: occ_shutdown() hwmon_device_unregister() occ_show_temp_1() occ_update_response() Lockdep reported the circular dependency with occ_shutdown() already holding the OCC mutex and hwmon_device_unregister() waiting on the sysfs side: WARNING: possible circular locking dependency detected ... (sysfs_lock) ... at: hwmon_device_unregister+0x12/0x30 [vuln_msv] ... (&test_occ.lock) ... at: occ_shutdown.constprop.0+0xe/0x40 [vuln_msv] occ_update_response.isra.0+0xb/0x20 [vuln_msv] occ_show_temp_1.constprop.0.isra.0+0x23/0x40 [vuln_msv] *** DEADLOCK *** Serialize hwmon registration and removal with a separate hwmon_lock. Under that lock, detach occ->hwmon and update occ->active while occ->lock is held so concurrent OCC state changes still see a stable state, then drop occ->lock before calling hwmon_device_unregister(). Remove the driver sysfs group before taking occ->lock in occ_shutdown(), so draining the driver attributes cannot wait while the OCC mutex is held. Also make OCC update callbacks return -ENODEV after deactivation, so callbacks that already passed sysfs active protection do not poll the hardware after teardown has detached the hwmon device.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2092952f22a7da98e76e84139ae202b1fc7ba899
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2a4c80ff3571498ec6a916273304b6650026b1b0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7ee43ec8e6774774abbe9dc3027225e01bc964a5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e31408734332b8cc611342cdaaab6ba492180156
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e7fd81e9fb1fe476d2131fec66c1138457810ed4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f0aad157576da199c146c1bb266442befa7912ca
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/hwmon/occ/common.c",
            "drivers/hwmon/occ/common.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2a4c80ff3571498ec6a916273304b6650026b1b0",
              "status": "affected",
              "version": "849b0156d9960da628a06756bb920d9571c15e66",
              "versionType": "git"
            },
            {
              "lessThan": "e7fd81e9fb1fe476d2131fec66c1138457810ed4",
              "status": "affected",
              "version": "849b0156d9960da628a06756bb920d9571c15e66",
              "versionType": "git"
            },
            {
              "lessThan": "2092952f22a7da98e76e84139ae202b1fc7ba899",
              "status": "affected",
              "version": "849b0156d9960da628a06756bb920d9571c15e66",
              "versionType": "git"
            },
            {
              "lessThan": "f0aad157576da199c146c1bb266442befa7912ca",
              "status": "affected",
              "version": "849b0156d9960da628a06756bb920d9571c15e66",
              "versionType": "git"
            },
            {
              "lessThan": "7ee43ec8e6774774abbe9dc3027225e01bc964a5",
              "status": "affected",
              "version": "849b0156d9960da628a06756bb920d9571c15e66",
              "versionType": "git"
            },
            {
              "lessThan": "e31408734332b8cc611342cdaaab6ba492180156",
              "status": "affected",
              "version": "849b0156d9960da628a06756bb920d9571c15e66",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "bc8a32726774286325b0cb0daab55b682cafc1ef",
              "versionType": "git"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.216",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/hwmon/occ/common.c",
            "drivers/hwmon/occ/common.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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-\u003elock 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-\u003elock again.  That gives the unregister\npaths the lock ordering occ-\u003elock -\u003e sysfs callback drain, while a callback\nhas the opposite edge sysfs callback -\u003e occ-\u003elock.\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  ... (\u0026test_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-\u003ehwmon and update occ-\u003eactive while occ-\u003elock\nis held so concurrent OCC state changes still see a stable state, then\ndrop occ-\u003elock before calling hwmon_device_unregister().  Remove the\ndriver sysfs group before taking occ-\u003elock 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."
    }
  ],
  "id": "CVE-2026-80660",
  "lastModified": "2026-08-28T08:16:51.160",
  "metrics": {},
  "published": "2026-08-28T08:16:51.160",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2092952f22a7da98e76e84139ae202b1fc7ba899"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2a4c80ff3571498ec6a916273304b6650026b1b0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7ee43ec8e6774774abbe9dc3027225e01bc964a5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e31408734332b8cc611342cdaaab6ba492180156"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e7fd81e9fb1fe476d2131fec66c1138457810ed4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f0aad157576da199c146c1bb266442befa7912ca"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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