CVE-2026-89806 drm/sysfb: ofdrm: Fix integer overflow in fb_size calculation
An integer overflow in the Linux kernel's ofdrm driver can cause undefined behavior, potentially leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89806?
CVE-2026-89806 is a high-severity vulnerability in Linux, published on 16 Sep 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:
drm/sysfb: ofdrm: Fix integer overflow in fb_size calculation
The framebuffer size calculation `fb_size = linebytes * height` can overflow when both values are large (e.g., 46341 * 46341 > INT_MAX). Since linebytes and height are both int types, the multiplication is performed as int * int, which results in undefined behavior on overflow.
Use check_mul_overflow() to detect and prevent this overflow, consistent with the approach used in simpledrm.c and corebootdrm.c.
Which versions are affected by CVE-2026-89806?
How do I fix CVE-2026-89806?
Apply the vendor's patch.
Is CVE-2026-89806 being exploited?
There is no known exploitation of CVE-2026-89806 in the wild and no public exploit code.
Sources
Also known as AZL-101526, BELL-CVE-2026-89806, DEBIAN-CVE-2026-89806, GHSA-2f2m-wrrx-qjxp, UBUNTU-CVE-2026-89806.