Medium 5.5Published Sep 11, 2025

CVE-2025-39742RDMA: hfi1: fix possible divide-by-zero in find_hw_thread_mask()

Updated under an hour ago (Oct 26, 2026, 5:10 PM ET)

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Exploited in the last 30 days

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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: May 12, 2026
First seen by InfoSec Signals: Oct 19, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from b094a36f90975373c3a241839869217a65f17d81 before 9bba1a9994c523b44db64f63b564b4719ea2b7ef; from b094a36f90975373c3a241839869217a65f17d81 before 1a7cf828ed861de5be1aff99e10f114b363c19d3; from b094a36f90975373c3a241839869217a65f17d81 before 9d3211cb61a0773a2440d0a0698c1e6e7429f907; from b094a36f90975373c3a241839869217a65f17d81 before 4b4317b0d758ff92ba96f4e448a8992a6fe607bf; from b094a36f90975373c3a241839869217a65f17d81 before 89fdac333a17ed990b41565630ef4791782e02f5; from b094a36f90975373c3a241839869217a65f17d81 before 9b05e91afe948ed819bf87d7ba0fccf451ed79a6; from b094a36f90975373c3a241839869217a65f17d81 before 31d0599a23efdbfe579bfbd1eb8f8c942f13744d; from b094a36f90975373c3a241839869217a65f17d81 before ac53f377393cc85156afdc90b636e84e544a6f96; and 1 more ranges	CNA record
Siemens SIMATIC CN 4100 siemens:simatic_cn_4100 (from the name)	before V5.0	CISA ADP
linux linux_kernel linux:linux_kernel	from 4.8 before 5.4.297; from 5.5 before 5.10.241; from 5.11 before 5.15.190; from 5.16 before 6.1.149; from 6.2 before 6.6.103; from 6.7 before 6.12.43; from 6.13 before 6.15.11; from 6.16 before 6.16.2	NVD
debian debian_linux debian:debian_linux	11.0	NVD

References

References

https://git.kernel.org/stable/c/9bba1a9994c523b44db64f63b564b4719ea2b7ef	patch
https://git.kernel.org/stable/c/1a7cf828ed861de5be1aff99e10f114b363c19d3	patch
https://git.kernel.org/stable/c/9d3211cb61a0773a2440d0a0698c1e6e7429f907	patch
https://git.kernel.org/stable/c/4b4317b0d758ff92ba96f4e448a8992a6fe607bf	patch
https://git.kernel.org/stable/c/89fdac333a17ed990b41565630ef4791782e02f5	patch
https://git.kernel.org/stable/c/9b05e91afe948ed819bf87d7ba0fccf451ed79a6	patch
https://git.kernel.org/stable/c/31d0599a23efdbfe579bfbd1eb8f8c942f13744d	patch
https://git.kernel.org/stable/c/ac53f377393cc85156afdc90b636e84e544a6f96	patch
https://git.kernel.org/stable/c/59f7d2138591ef8f0e4e4ab5f1ab674e8181ad3a	patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html	mailing-list, third-party-advisory
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.