A logic error in the DRM scheduler’s prepare_job() callback causes the kernel to undercount native dependencies for paired job fences, leading to premature unblocking of job execution and incomplete command writes to the command completion control block (CCCB). This can result in kernel warnings, job timeouts, and unreliable GPU operations, effectively denying service to applications relying on GPU acceleration.

The vulnerability affects the Linux kernel's DRM/powervr subsystems on all Linux platforms. No specific kernel version is listed, but the bug was addressed in a commit referenced in the provided kernel links. Users running kernels that still include the buggy drm/imagination scheduler logic are impacted.

The CVSS score is 4.7, indicating a moderate severity. The EPSS score is < 1%, suggesting a low probability of exploitation. The vulnerability is not listed in CISA KEV. The likely attack vector is a local attacker with kernel privileges or an exploit that causes the kernel to schedule paired geometry and fragment jobs in an almost full CCCB. The exploit could lead to kernel warnings and a denial of GPU service, potentially causing system instability without granting arbitrary code execution.