CVE-2026-31603 staging: sm750fb: fix division by zero in ps_to_hz()

Medium 5.5 Published Updated

A local attacker can cause a kernel crash by passing a zero pixclock value to the sm750fb framebuffer driver, resulting in a division by zero error.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2026-31603?

CVE-2026-31603 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

staging: sm750fb: fix division by zero in ps_to_hz()

ps_to_hz() is called from hw_sm750_crtc_set_mode() without validating that pixclock is non-zero. A zero pixclock passed via FBIOPUT_VSCREENINFO causes a division by zero.

Fix by rejecting zero pixclock in lynxfb_ops_check_var(), consistent with other framebuffer drivers.

Weakness: CWE-369

Which versions are affected by CVE-2026-31603?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-31603?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-31603 being exploited?

There is no known exploitation of CVE-2026-31603 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as AZL-83747, BELL-CVE-2026-31603, DEBIAN-CVE-2026-31603, GHSA-rfh9-x593-fmpr, ROOT-OS-DEBIAN-11-CVE-2026-31603, ROOT-OS-DEBIAN-12-CVE-2026-31603 and 3 more.

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