Linux Kernel up to 6.17.2 net netdev_alloc_skb_ip_align null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.15.194/6.1.155/6.6.111/6.12.52/6.17.2. It has been rated as critical. This vulnerability affects the function netdev_alloc_skb_ip_align of the component net. Performing a manipulation results in null pointer dereference. This vulnerability is reported as CVE-2025-40053. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 5.15.194/6.1.155/6.6.111/6.12.52/6.17.2. This affects the function netdev_alloc_skb_ip_align of the component net. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: dlink: handle copy_thresh allocation failure The driver did not handle failure of `netdev_alloc_skb_ip_align()`. If the allocation failed, dereferencing `skb->protocol` could lead to a NULL pointer dereference. This patch tries to allocate `skb`. If the allocation fails, it falls back to the normal path. Tested-on: D-Link DGE-550T Rev-A3

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-40053 since 04/16/2025. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 271901 (Linux Distros Unpatched Vulnerability : CVE-2025-40053), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3 or 6.18-rc1 eliminates this vulnerability. Applying the patch 5aa9b885602811a026a3f45c92ea2b4b04c54f09/9d49e4b14609e1a20d931e718962c4b6b5485174/ea87151df398d407a632c7bf63013290f01c5009/7ed5010fef0930f4322d620052edc854ef3ec41f/fd7b6b2c920d7fd370a612be416a904d6e1ebe55/8169a6011c5fecc6cb1c3654c541c567d3318de8 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 (271901) and CERT Bund (WID-SEC-2025-2431). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • IBM QRadar SIEM
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Microsoft Azure
  • Dell NetWorker
  • Dell ECS

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
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: 271901
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-40053

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.195/6.1.156/6.6.112/6.12.53/6.17.3/6.18-rc1
Patch: 5aa9b885602811a026a3f45c92ea2b4b04c54f09/9d49e4b14609e1a20d931e718962c4b6b5485174/ea87151df398d407a632c7bf63013290f01c5009/7ed5010fef0930f4322d620052edc854ef3ec41f/fd7b6b2c920d7fd370a612be416a904d6e1ebe55/8169a6011c5fecc6cb1c3654c541c567d3318de8

Timelineinfo

04/16/2025 CVE reserved
10/28/2025 +195 days Advisory disclosed
10/28/2025 +0 days VulDB entry created
05/20/2026 +204 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40053 (🔒)
GCVE (CVE): GCVE-0-2025-40053
GCVE (VulDB): GCVE-100-330267
CERT Bund: WID-SEC-2025-2431 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 10/28/2025 14:50
Updated: 05/20/2026 02:38
Changes: 10/28/2025 14:50 (59), 10/29/2025 10:03 (2), 10/30/2025 05:51 (7), 10/31/2025 10:08 (1), 11/24/2025 15:14 (1), 12/22/2025 01:42 (1), 02/08/2026 17:31 (1), 02/15/2026 20:05 (1), 05/20/2026 02:38 (1)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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