CVE-2026-46209

Technical Description

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

drm/gem: Fix inconsistent plane dimension calculation in drm_gem_fb_init_with_funcs()

drm_gem_fb_init_with_funcs() computes sub-sampled plane dimensions

using plain integer division:

unsigned int width = mode_cmd->width / (i ? info->hsub : 1);

unsigned int height = mode_cmd->height / (i ? info->vsub : 1);

However, the ioctl-level framebuffer_check() in drm_framebuffer.c uses

drm_format_info_plane_width/height() which round up dimensions via

DIV_ROUND_UP(). This inconsistency corrupts the subsequent GEM object

size check for certain pixel format and dimension combinations.

For example, with NV12 (vsub=2) and a 1-pixel-tall framebuffer the

GEM size validation path sees height=0 instead of height=1. The

expression (height - 1) then wraps to UINT_MAX as an unsigned int,

causing min_size to overflow and wrap back to a small value. A tiny

GEM object therefore passes the size guard, yet when the GPU accesses

the ch

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References