Linux Kernel up to 6.16.1 RDMA find_hw_thread_mask divide by zero

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

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.16.1. The impacted element is the function find_hw_thread_mask of the component RDMA. Such manipulation leads to divide by zero. This vulnerability is referenced as CVE-2025-39742. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.16.1. Affected by this issue is the function find_hw_thread_mask of the component RDMA. The manipulation with an unknown input leads to a divide by zero vulnerability. Using CWE to declare the problem leads to CWE-369. The product divides a value by zero. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: RDMA: hfi1: fix possible divide-by-zero in find_hw_thread_mask() The function divides number of online CPUs by num_core_siblings, and later checks the divider by zero. This implies a possibility to get and divide-by-zero runtime error. Fix it by moving the check prior to division. This also helps to save one indentation level.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-39742 since 04/16/2025. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 264750 (Linux Distros Unpatched Vulnerability : CVE-2025-39742), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2 or 6.17-rc1 eliminates this vulnerability. Applying a patch 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 (264750), EUVD (EUVD-2025-28969) and CERT Bund (WID-SEC-2025-2040). Once again VulDB remains the best source for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Fedora Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel
  • Proxmox Virtual Environment
  • Proxmox Backup Server
  • Dell Secure Connect Gateway
  • IBM QRadar SIEM

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

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

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Divide by zero
CWE: CWE-369 / 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: 264750
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-39742

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.297/5.10.241/5.15.190/6.1.149/6.6.103/6.12.43/6.15.11/6.16.2/6.17-rc1
Patch: git.kernel.org

Timelineinfo

04/16/2025 CVE reserved
09/11/2025 +148 days Advisory disclosed
09/11/2025 +0 days VulDB entry created
01/10/2026 +121 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39742 (🔒)
GCVE (CVE): GCVE-0-2025-39742
GCVE (VulDB): GCVE-100-323660
EUVD: 🔒
CERT Bund: WID-SEC-2025-2040 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 09/11/2025 19:30
Updated: 01/10/2026 07:35
Changes: 09/11/2025 19:30 (58), 09/12/2025 15:13 (7), 09/14/2025 20:45 (2), 09/15/2025 11:01 (1), 11/07/2025 15:11 (1), 11/15/2025 20:25 (1), 01/09/2026 21:03 (10), 01/10/2026 07:35 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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