Linux Kernel up to 7.1.4 occ driver occ_shutdown locking

CVSS Meta Temp Score
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CTI Interest Score
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6.2$0-$5k0.37

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.1.177/6.6.144/6.12.96/6.18.39/7.1.4. It has been declared as critical. This issue affects the function occ_shutdown of the component occ driver. Executing a manipulation can lead to locking. This vulnerability appears as CVE-2026-80660. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.1.177/6.6.144/6.12.96/6.18.39/7.1.4 and classified as critical. This vulnerability affects the function occ_shutdown of the component occ driver. The manipulation with an unknown input leads to a locking vulnerability. The CWE definition for the vulnerability is CWE-667. The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-80660 since 08/26/2026. The exploitation appears to be easy. The attack can be initiated remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 08/28/2026).

Upgrading to version 6.1.178, 6.6.145, 6.12.97, 6.18.40 or 7.1.5 eliminates this vulnerability. Applying the patch 2a4c80ff3571498ec6a916273304b6650026b1b0/e7fd81e9fb1fe476d2131fec66c1138457810ed4/2092952f22a7da98e76e84139ae202b1fc7ba899/f0aad157576da199c146c1bb266442befa7912ca/7ee43ec8e6774774abbe9dc3027225e01bc964a5/e31408734332b8cc611342cdaaab6ba492180156 is able to eliminate this problem.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.2

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Locking
CWE: CWE-667
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.178/6.6.145/6.12.97/6.18.40/7.1.5
Patch: 2a4c80ff3571498ec6a916273304b6650026b1b0/e7fd81e9fb1fe476d2131fec66c1138457810ed4/2092952f22a7da98e76e84139ae202b1fc7ba899/f0aad157576da199c146c1bb266442befa7912ca/7ee43ec8e6774774abbe9dc3027225e01bc964a5/e31408734332b8cc611342cdaaab6ba492180156

Timelineinfo

08/26/2026 CVE reserved
08/28/2026 +2 days Advisory disclosed
08/28/2026 +0 days VulDB entry created
08/28/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80660 (🔒)
GCVE (CVE): GCVE-0-2026-80660
GCVE (VulDB): GCVE-100-396598

Entryinfo

Created: 08/28/2026 10:43
Changes: 08/28/2026 10:43 (59)
Complete: 🔍
Cache ID: 216::103

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