Linux Kernel up to 6.6.79/6.12.16/6.13.4/6.14-rc3 device_release use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.79/6.12.16/6.13.4/6.14-rc3. It has been rated as critical. The impacted element is the function device_release. The manipulation leads to use after free. This vulnerability is uniquely identified as CVE-2025-21856. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.79/6.12.16/6.13.4/6.14-rc3. It has been rated as critical. This issue affects the function device_release. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: s390/ism: add release function for struct device According to device_release() in /drivers/base/core.c, a device without a release function is a broken device and must be fixed. The current code directly frees the device after calling device_add() without waiting for other kernel parts to release their references. Thus, a reference could still be held to a struct device, e.g., by sysfs, leading to potential use-after-free issues if a proper release function is not set.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2025-21856 since 12/29/2024. The exploitation is known to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 12/14/2025).

The vulnerability scanner Nessus provides a plugin with the ID 234058 (SUSE SLES15 / openSUSE 15 Security Update : kernel (SUSE-SU-2025:1178-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.80, 6.12.17, 6.13.5 or 6.14-rc4 eliminates this vulnerability. Applying the patch 940d15254d2216b585558bcf36312da50074e711/0505ff2936f166405d81d0d454a81d9c14124344/e26e8ac27351f457091459a0a355bacd06d5bb2b/915e34d5ad35a6a9e56113f852ade4a730fb88f0 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (234058) and CERT Bund (WID-SEC-2025-0545). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • Siemens SIMATIC S7
  • RESF Rocky Linux
  • SolarWinds Security Event Manager
  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 234058
Nessus Name: SUSE SLES15 / openSUSE 15 Security Update : kernel (SUSE-SU-2025:1178-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 6.6.80/6.12.17/6.13.5/6.14-rc4
Patch: 940d15254d2216b585558bcf36312da50074e711/0505ff2936f166405d81d0d454a81d9c14124344/e26e8ac27351f457091459a0a355bacd06d5bb2b/915e34d5ad35a6a9e56113f852ade4a730fb88f0

Timelineinfo

12/29/2024 🔍
03/12/2025 +73 days 🔍
03/12/2025 +0 days 🔍
12/14/2025 +277 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-21856 (🔍)
GCVE (CVE): GCVE-0-2025-21856
GCVE (VulDB): GCVE-100-299537
CERT Bund: WID-SEC-2025-0545 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 03/12/2025 11:08
Updated: 12/14/2025 21:57
Changes: 03/12/2025 11:08 (58), 04/10/2025 10:13 (2), 12/14/2025 21:57 (7)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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