CVE-2025-38312: debian linux — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: fbdev: core: fbcvt: avoid division by 0 in fb_cvt_hperiod() In fb_find_mode_cvt(), iff mode->refresh somehow happens to be 0x80000000, cvt.f_refresh will become 0 when multiplying it by 2 due to overflow. It's then passed to fb_cvt_hperiod(), where it's used as a divider -- division by 0 will result in kernel oops. Add a sanity check for cvt.f_refresh to avoid such overflow... Found by Linux Verification Center (linuxtesting.org) with the Svace static analysis tool.

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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-369 CWE-369

Affected Products

Vendor	Product	Versions
linux	linux_kernel	2.6.14 — 5.4.295
linux	linux_kernel	5.5 — 5.10.239
linux	linux_kernel	5.11 — 5.15.186
linux	linux_kernel	5.16 — 6.1.142
linux	linux_kernel	6.2 — 6.6.94
linux	linux_kernel	6.7 — 6.12.34
linux	linux_kernel	6.13 — 6.15.3
debian	debian_linux	All

References

Advisories & Patches

https://git.kernel.org/stable/c/2d63433e8eaa3c91b2948190e395bc67009db0d9 https://git.kernel.org/stable/c/3f6dae09fc8c306eb70fdfef70726e1f154e173a https://git.kernel.org/stable/c/53784073cbad18f75583fd3da9ffdfc4d1f05405 https://git.kernel.org/stable/c/54947530663edcbaaee1314c01fdd8c72861b124 https://git.kernel.org/stable/c/610f247f2772e4f92b63442125a1b7ade79898d8 https://git.kernel.org/stable/c/9027ce4c037b566b658b8939a76326b7125e3627 https://git.kernel.org/stable/c/ab91647acdf43b984824776559a452212eaeb21a https://git.kernel.org/stable/c/b235393b9f43ff86a38ca2bde6372312ea215dc5

Other References

https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html https://cert-portal.siemens.com/productcert/html/ssa-082556.html

Frequently Asked Questions

What is CVE-2025-38312? +

In the Linux kernel, the following vulnerability has been resolved: fbdev: core: fbcvt: avoid division by 0 in fb_cvt_hperiod() In fb_find_mode_cvt(), iff mode->refresh somehow happens to be 0x80000000, cvt.f_refresh will become 0 when multiplying it by 2 due to overflow. It's then passed to fb_cvt_hperiod(), where it's used as a divider -- division by 0 will result in kernel oops. Add a sanity check for cvt.f_refresh to avoid such overflow... Found by Linux Verification Center (linuxtesting.org) with the Svace static analysis tool. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2025-38312? +

CVE-2025-38312 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-2025-38312? +

CVE-2025-38312 affects products from debian, linux, specifically: debian_linux, linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-38312? +

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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