Linux Kernel up to 6.1.135/6.6.88/6.12.25/6.14.4 p9_client_write null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.1.135/6.6.88/6.12.25/6.14.4. This impacts the function p9_client_write. Performing a manipulation results in null pointer dereference. This vulnerability was named CVE-2025-37879. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.1.135/6.6.88/6.12.25/6.14.4. This affects the function p9_client_write. 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: 9p/net: fix improper handling of bogus negative read/write replies In p9_client_write() and p9_client_read_once(), if the server incorrectly replies with success but a negative write/read count then we would consider written (negative) <= rsize (positive) because both variables were signed. Make variables unsigned to avoid this problem. The reproducer linked below now fails with the following error instead of a null pointer deref: 9pnet: bogus RWRITE count (4294967295 > 3)

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-37879 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 237504 (Debian dla-4193 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.136, 6.6.89, 6.12.26, 6.14.5 or 6.15-rc1 eliminates this vulnerability. Applying the patch 468ff4a7c61fb811c596a7c44b6a5455e40fd12b/a68768e280b7d0c967ea509e791bb9b90adc94a5/c548f95688e2b5ae0e2ae43d53cf717156c7d034/374e4cd75617c8c2552f562f39dd989583f5c330/d0259a856afca31d699b706ed5e2adf11086c73b 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 (237504) and CERT Bund (WID-SEC-2025-0991). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • Dell Avamar
  • Open Source Linux Kernel
  • Dell NetWorker
  • Dell Secure Connect Gateway

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

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

NVD Base Score: 7.1
NVD Vector: 🔍

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: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 237504
Nessus Name: Debian dla-4193 : linux-config-6.1 - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 6.1.136/6.6.89/6.12.26/6.14.5/6.15-rc1
Patch: 468ff4a7c61fb811c596a7c44b6a5455e40fd12b/a68768e280b7d0c967ea509e791bb9b90adc94a5/c548f95688e2b5ae0e2ae43d53cf717156c7d034/374e4cd75617c8c2552f562f39dd989583f5c330/d0259a856afca31d699b706ed5e2adf11086c73b

Timelineinfo

04/16/2025 🔍
05/09/2025 +23 days 🔍
05/09/2025 +0 days 🔍
01/31/2026 +267 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-37879 (🔍)
GCVE (CVE): GCVE-0-2025-37879
GCVE (VulDB): GCVE-100-308163
CERT Bund: WID-SEC-2025-0991 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 05/09/2025 09:12
Updated: 01/31/2026 04:01
Changes: 05/09/2025 09:12 (58), 05/30/2025 15:01 (2), 11/13/2025 03:34 (12), 01/31/2026 04:01 (7)
Complete: 🔍
Cache ID: 216::103

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

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