Linux Kernel up to 6.17.8 ndo_netpoll_cleanup 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 6.17.8. It has been rated as critical. The affected element is the function ndo_netpoll_cleanup. The manipulation leads to use after free. This vulnerability is traded as CVE-2025-68245. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.17.8 and classified as critical. This issue affects the function ndo_netpoll_cleanup. 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: net: netpoll: fix incorrect refcount handling causing incorrect cleanup commit efa95b01da18 ("netpoll: fix use after free") incorrectly ignored the refcount and prematurely set dev->npinfo to NULL during netpoll cleanup, leading to improper behavior and memory leaks. Scenario causing lack of proper cleanup: 1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is allocated, and refcnt = 1 - Keep in mind that npinfo is shared among all netpoll instances. In this case, there is just one. 2) Another netpoll is also associated with the same NIC and npinfo->refcnt += 1. - Now dev->npinfo->refcnt = 2; - There is just one npinfo associated to the netdev. 3) When the first netpolls goes to clean up: - The first cleanup succeeds and clears np->dev->npinfo, ignoring refcnt. - It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);` - Set dev->npinfo = NULL, without proper cleanup - No ->ndo_netpoll_cleanup() is either called 4) Now the second target tries to clean up - The second cleanup fails because np->dev->npinfo is already NULL. * In this case, ops->ndo_netpoll_cleanup() was never called, and the skb pool is not cleaned as well (for the second netpoll instance) - This leaks npinfo and skbpool skbs, which is clearly reported by kmemleak. Revert commit efa95b01da18 ("netpoll: fix use after free") and adds clarifying comments emphasizing that npinfo cleanup should only happen once the refcount reaches zero, ensuring stable and correct netpoll behavior.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2025-68245 since 12/16/2025. 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 02/21/2026).

The vulnerability scanner Nessus provides a plugin with the ID 298384 (Oracle Linux 8 : Unbreakable Enterprise kernel (ELSA-2026-50100)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.302, 5.10.247, 5.15.197, 6.1.159, 6.6.117, 6.12.59 or 6.17.9 eliminates this vulnerability. Applying the patch 8e6a50edad11e3e1426e4c29e7aa6201f3468ac2/9b0bb18b4b9dc017c1825a2c5e763615e34a1593/890472d6fbf062e6de7fdd56642cb305ab79d669/4afd4ebbad52aa146838ec23082ba393e426a2bb/c645693180a98606c430825223d2029315d85e9d/c79a6d9da29219616b118a3adce9a14cd30f9bd0/9a51b5ccd1c79afec1c03a4e1e6688da52597556/49c8d2c1f94cc2f4d1a108530d7ba52614b874c2 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 (298384) and CERT Bund (WID-SEC-2025-2868). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • 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: 298384
Nessus Name: Oracle Linux 8 : Unbreakable Enterprise kernel (ELSA-2026-50100)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.302/5.10.247/5.15.197/6.1.159/6.6.117/6.12.59/6.17.9
Patch: 8e6a50edad11e3e1426e4c29e7aa6201f3468ac2/9b0bb18b4b9dc017c1825a2c5e763615e34a1593/890472d6fbf062e6de7fdd56642cb305ab79d669/4afd4ebbad52aa146838ec23082ba393e426a2bb/c645693180a98606c430825223d2029315d85e9d/c79a6d9da29219616b118a3adce9a14cd30f9bd0/9a51b5ccd1c79afec1c03a4e1e6688da52597556/49c8d2c1f94cc2f4d1a108530d7ba52614b874c2

Timelineinfo

12/16/2025 Advisory disclosed
12/16/2025 +0 days CVE reserved
12/16/2025 +0 days VulDB entry created
02/21/2026 +67 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-68245 (🔒)
GCVE (CVE): GCVE-0-2025-68245
GCVE (VulDB): GCVE-100-336749
CERT Bund: WID-SEC-2025-2868 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 12/16/2025 15:57
Updated: 02/21/2026 23:02
Changes: 12/16/2025 15:57 (58), 01/20/2026 02:09 (7), 02/03/2026 13:17 (1), 02/09/2026 20:20 (2), 02/21/2026 23:02 (1)
Complete: 🔍
Cache ID: 216::103

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