Linux Kernel up to 7.1.3 firmware_loader firmware_upload_register reference count

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4.7	$0-$5k	1.59

Summaryinfo

A vulnerability categorized as problematic has been discovered in Linux Kernel up to 6.1.177/6.6.144/6.12.95/6.18.38/7.1.3. Affected by this vulnerability is the function firmware_upload_register of the component firmware_loader. Such manipulation leads to reference count. This vulnerability is traded as CVE-2026-64376. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.177/6.6.144/6.12.95/6.18.38/7.1.3. It has been rated as problematic. Affected by this issue is the function firmware_upload_register of the component firmware_loader. The manipulation with an unknown input leads to a reference count vulnerability. Using CWE to declare the problem leads to CWE-911. The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: firmware_loader: fix device reference leak in firmware_upload_register() firmware_upload_register() -> fw_create_instance() -> device_initialize() After fw_create_instance() succeeds, the lifetime of the embedded struct device is expected to be managed through the device core reference counting, since fw_create_instance() has already called device_initialize(). In firmware_upload_register(), if alloc_lookup_fw_priv() fails after fw_create_instance() succeeds, the code reaches free_fw_sysfs and frees fw_sysfs directly instead of releasing the device reference with put_device(). This may leave the reference count of the embedded struct device unbalanced, resulting in a refcount leak. The issue was identified by a static analysis tool I developed and confirmed by manual review. Fix this by using put_device(fw_dev) in the failure path and letting fw_dev_release() handle the final cleanup, instead of freeing the instance directly from the error path.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-64376 since 07/19/2026. The exploitation is known to be easy. The attack may be launched remotely. Additional levels of successful authentication are needed for exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch 517676ec7dfca064e08f94007a4abd21969de0a0/46d403da376a8b7c1187193294953816e1a8d7fe/2619b47a0c8114eef980a56ade7e3ef4b58eb384/92f41769e5fd16bcd9ba97500d0517332e0a5b45/15432f19562fdb9199cce6d9fc24db12c71ed574/896df22ee57648b0c505bd76ddbc6b2341834696 is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.177
• 6.6.144
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
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• 6.12.84
• 6.12.85
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• 6.12.87
• 6.12.88
• 6.12.89
• 6.12.90
• 6.12.91
• 6.12.92
• 6.12.93
• 6.12.94
• 6.12.95
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
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• 6.18.13
• 6.18.14
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• 6.18.18
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• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.7

VulDB Base Score: 4.9
VulDB Temp Score: 4.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Reference count
CWE: CWE-911 / CWE-664
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.178/6.6.145/6.12.96/6.18.39/7.1.4/7.2-rc1
Patch: 517676ec7dfca064e08f94007a4abd21969de0a0/46d403da376a8b7c1187193294953816e1a8d7fe/2619b47a0c8114eef980a56ade7e3ef4b58eb384/92f41769e5fd16bcd9ba97500d0517332e0a5b45/15432f19562fdb9199cce6d9fc24db12c71ed574/896df22ee57648b0c505bd76ddbc6b2341834696

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64376 (🔒)
GCVE (CVE): GCVE-0-2026-64376
GCVE (VulDB): GCVE-100-383174

Entryinfo

Created: 07/25/2026 17:59
Changes: 07/25/2026 17:59 (59)
Complete: 🔍
Cache ID: 216::103

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