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Vulnerability · Published Sep 11, 2025 · Assigned by Linux

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

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 92.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.153-1DEBIAN-CVE-2025-39742
Debian:13linux6.12.43-1DEBIAN-CVE-2025-39742
Debian:14linux6.16.3-1DEBIAN-CVE-2025-39742
Ubuntu:22.04:LTSlinux5.15.0-163.173UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux6.8.0-100.100UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-aws5.15.0-1097.104UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-aws6.8.0-1046.49UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1046.49~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure5.15.0-1101.110UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-azure6.8.0-1046.52UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1051.57~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1102.111.1UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1046.53UBUNTU-CVE-2025-39742
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1046.53~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-gcp5.15.0-1097.106UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-gcp6.8.0-1047.50UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1047.50~22.04.2UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-gke5.15.0-1093.99UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-gke6.8.0-1043.48UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1080.88UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1030.33UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-100.100~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-ibm5.15.0-1091.94UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-ibm6.8.0-1044.44UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1044.44~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1092.98UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-kvm5.15.0-1089.94UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-163.173UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-100.100.1UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-100.100.1~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1092.93UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1046.49UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1046.49~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1046.49.1UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1049.49UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1020.20UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1038.38UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-oracle5.15.0-1094.100UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-oracle6.8.0-1043.44UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1043.44~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-raspi5.15.0-1091.94UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-raspi6.8.0-1047.51UBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-100.100~22.04.1UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2025-39742
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1023.24UBUNTU-CVE-2025-39742
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1061.65UBUNTU-CVE-2025-39742

Affected products (as reported)

VendorProductVersions
Linux Linux b094a36f90975373c3a241839869217a65f17d81 – before 9bba1a9994c523b44db64f63b564b4719ea2b7efb094a36f90975373c3a241839869217a65f17d81 – before 1a7cf828ed861de5be1aff99e10f114b363c19d3b094a36f90975373c3a241839869217a65f17d81 – before 9d3211cb61a0773a2440d0a0698c1e6e7429f907b094a36f90975373c3a241839869217a65f17d81 – before 4b4317b0d758ff92ba96f4e448a8992a6fe607bfb094a36f90975373c3a241839869217a65f17d81 – before 89fdac333a17ed990b41565630ef4791782e02f5b094a36f90975373c3a241839869217a65f17d81 – before 9b05e91afe948ed819bf87d7ba0fccf451ed79a6b094a36f90975373c3a241839869217a65f17d81 – before 31d0599a23efdbfe579bfbd1eb8f8c942f13744db094a36f90975373c3a241839869217a65f17d81 – before ac53f377393cc85156afdc90b636e84e544a6f96
Linux Linux 4.8

References