Advisory [CVE-2026-53139] Skip CSD when it has zeroed workgroups

In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Skip CSD when it has zeroed workgroups A compute shader dispatch encodes its workgroup counts in the CFG0..CFG2 registers. Kicking off a dispatch with a zero count in any of the three dimensions is invalid.

First, the hardware will process 0 as 65536, while the user-space driver exposes a maximum of 65535. Over that, a submission with a zeroed workgroup dimension should be a no-op.

These zeroed counts can reach the dispatch path through an indirect CSD job, whose workgroup counts are only known once the indirect buffer is read and may legitimately be zero, but such scenario should only result in a no-op.

Overwrite the indirect CSD job workgroup counts with the indirect BO ones, even if they are zeroed, and don't submit the job to the hardware when any of the workgroup counts is zero, so the job completes immediately instead of running the shader. A flaw was found in the Linux kernel's graphics driver for Broadcom V3D (VideoCore V) GPUs.

This vulnerability occurs when a compute shader dispatch (CSD) is initiated with zero workgroup counts, which the hardware could misinterpret as a very large number. This misinterpretation could lead to unexpected system behavior or a denial of service (DoS), where the system becomes unresponsive or crashes.

Red Hat severity: not rated. Weakness: CWE-1284.