Description
In the Linux kernel, the following vulnerability has been resolved:

fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO

Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide
by zero error"), we also need to prevent that same crash from happening
in the udlfb driver as it uses pixclock directly when dividing, which
will crash.
Published: 2026-04-24
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The promoted vulnerability is a divide‑by‑zero error in the udlfb framebuffer driver that can be triggered via the FBIOPUT_VSCREENINFO ioctl. When the driver attempts to perform a division operation using pixclock without validating the divisor, a kernel crash occurs, causing the system to become unresponsive. The flaw does not provide direct escalation or data disclosure but results in an unstable system state and potential loss of uptime.

Affected Systems

All Linux kernel builds that include the udlfb framebuffer driver are impacted, regardless of distribution. Any machine that runs a kernel containing the udlfb code before the fix will expose the flaw. This includes generic desktop and server kernels that ship with the driver enabled.

Risk and Exploitability

The CVSS score of 5.5, combined with an EPSS score of < 1%, indicates a very low likelihood of exploitation in the wild. The flaw is not listed in CISA’s Known Exploited Vulnerabilities catalog. The attack vector is local: an entity that can open the framebuffer device and issue the FBIOPUT_VSCREENINFO ioctl can trigger the crash. Privileged users typically have access to the framebuffer; thus the risk is confined to systems where non‑root processes might be able to use the device, or where privilege escalation exists.

Generated by OpenCVE AI on April 30, 2026 at 04:07 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Install a Linux kernel version that contains the fbdev/udlfb divide‑by‑zero fix.
  • If upgrading the kernel cannot be performed promptly, restrict access to framebuffer devices (/dev/fb*) by adjusting file permissions or disabling the udlfb driver in the kernel configuration, thereby preventing untrusted users from exercising the vulnerable ioctl.
  • Rebuild the kernel with the udlfb driver disabled if it is not required, eliminating the vulnerable code path.

Generated by OpenCVE AI on April 30, 2026 at 04:07 UTC.

Tracking

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Advisories
Source ID Title
Debian DSA Debian DSA DSA-6238-1 linux security update
History

Mon, 01 Jun 2026 17:00:00 +0000


Wed, 29 Apr 2026 19:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Mon, 27 Apr 2026 14:15:00 +0000


Mon, 27 Apr 2026 11:30:00 +0000


Sat, 25 Apr 2026 00:15:00 +0000


Fri, 24 Apr 2026 15:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide by zero error"), we also need to prevent that same crash from happening in the udlfb driver as it uses pixclock directly when dividing, which will crash.
Title fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-06-01T16:12:27.511Z

Reserved: 2026-03-09T15:48:24.122Z

Link: CVE-2026-31605

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2026-04-24T15:16:39.730

Modified: 2026-06-01T17:16:51.190

Link: CVE-2026-31605

cve-icon Redhat

Severity :

Publid Date: 2026-04-24T00:00:00Z

Links: CVE-2026-31605 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-30T04:15:26Z

Weaknesses