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.

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Linux Kernel Subscribe
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4327-1 linux security update
Debian DLA Debian DLA DLA-4328-1 linux-6.1 security update
Debian DSA Debian DSA DSA-6009-1 linux security update
EUVD EUVD EUVD-2025-28969 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.
Ubuntu USN Ubuntu USN USN-7909-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7909-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7909-3 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7910-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7909-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7910-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7909-5 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7933-1 Linux kernel (KVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7938-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8031-1 Linux kernel (GCP) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 09 Jan 2026 19:15:00 +0000

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Weaknesses CWE-369
CPEs cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Fri, 02 Jan 2026 15:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Mon, 03 Nov 2025 18:30:00 +0000


Fri, 12 Sep 2025 08:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Fri, 12 Sep 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Thu, 11 Sep 2025 17:00:00 +0000

Type Values Removed Values Added
Description 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.
Title RDMA: hfi1: fix possible divide-by-zero in find_hw_thread_mask()
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-01-02T15:31:53.787Z

Reserved: 2025-04-16T07:20:57.120Z

Link: CVE-2025-39742

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-09-11T17:15:36.733

Modified: 2026-01-09T19:09:30.947

Link: CVE-2025-39742

cve-icon Redhat

Severity : Important

Publid Date: 2025-09-11T00:00:00Z

Links: CVE-2025-39742 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-09-12T08:02:39Z

Weaknesses