CVE-2025-21962: linux kernel Integer Overflow — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing closetimeo mount option User-provided mount parameter closetimeo of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-190 Integer Overflow

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.15.107 — 5.15.180
linux	linux_kernel	6.0 — 6.1.132
linux	linux_kernel	6.2 — 6.6.84
linux	linux_kernel	6.7 — 6.12.20
linux	linux_kernel	6.13 — 6.13.8
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/1c46673be93dd2954f44fe370fb4f2b8e6214224 https://git.kernel.org/stable/c/513f6cf2e906a504b7ab0b62b2eea993a6f64558 https://git.kernel.org/stable/c/6c13fcb7cf59ae65940da1dfea80144e42921e53 https://git.kernel.org/stable/c/9968fcf02cf6b0f78fbacf3f63e782162603855a https://git.kernel.org/stable/c/b24edd5c191c2689c59d0509f0903f9487eb6317 https://git.kernel.org/stable/c/d5a30fddfe2f2e540f6c43b59cf701809995faef

Other References

https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html

Frequently Asked Questions

What is CVE-2025-21962? +

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing closetimeo mount option User-provided mount parameter closetimeo of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2025-21962? +

CVE-2025-21962 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-21962? +

CVE-2025-21962 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21962? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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