CVE Catalog

CVE-2025-39742

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

7th percentile - higher than 7% of all known CVEs

Summary

In the Linux kernel RDMA hfi1 driver, find_hw_thread_mask() divides the number of online CPUs by num_core_siblings and only checks the divisor for zero afterwards. This can lead to a divide-by-zero runtime error.

Risk Assessment

A divide-by-zero in the kernel can cause a kernel panic and system unavailability, especially on machines with unusual CPU topology.

Recommendation

Update the Linux kernel to a version containing the fix that moves the check before the division.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS