CVE-2025-38312 | fbdev: core: fbcvt: avoid division by 0 in fb_cvt_hperiod()

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.

Published: 2025-07-10 Last update: 2026-05-12 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-38312 is rated Low Risk (31/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.09%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-38312

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-06 0.03% 0.09% +0.06%
2 2025-12-20 0.05% 0.03% -0.02%
3 2025-10-17 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38312

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2025-38312

GitHub Security Advisory for CVE-2025-38312

GHSA-qjhc-7f62-c8xv · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: fbdev: core: fbcvt: avoid...

OS Trackers for CVE-2025-38312

vendor priority summary link
debian not yet assigned CVE-2025-38312 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-38312
redhat medium — https://access.redhat.com/security/cve/CVE-2025-38312
suse medium CVE-2025-38312 severity moderate: SUSE including 491 source package names (2.1.3-6.67:kernel-default-base-6.4.0-32.1.21.10, 2.1.3-7.44:kernel-default-6.4.0-32.1, …), 995 product×package rows across 197 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (197 product lines)): Fixed 704, Known Affected 231, Known Not Affected 39, First Fixed 21. https://www.suse.com/security/cve/CVE-2025-38312/
ubuntu medium CVE-2025-38312 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1548 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1142, released 169, ignored 168, needed 44, not-affected 22, needs-triage 2, pending 1. https://ubuntu.com/security/CVE-2025-38312

Affected software / configurations for CVE-2025-38312

Vendor Product Version Raw CPE
linux linux_kernel >= 2.6.14, < 5.4.295 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.5, < 5.10.239 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.186 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.142 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.94 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.34 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.15.3 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-38312

URL Tags
https://git.kernel.org/stable/c/2d63433e8eaa3c91b2948190e395bc67009db0d9 Patch
https://git.kernel.org/stable/c/3f6dae09fc8c306eb70fdfef70726e1f154e173a Patch
https://git.kernel.org/stable/c/53784073cbad18f75583fd3da9ffdfc4d1f05405 Patch
https://git.kernel.org/stable/c/54947530663edcbaaee1314c01fdd8c72861b124 Patch
https://git.kernel.org/stable/c/610f247f2772e4f92b63442125a1b7ade79898d8 Patch
https://git.kernel.org/stable/c/9027ce4c037b566b658b8939a76326b7125e3627 Patch
https://git.kernel.org/stable/c/ab91647acdf43b984824776559a452212eaeb21a Patch
https://git.kernel.org/stable/c/b235393b9f43ff86a38ca2bde6372312ea215dc5 Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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