The Linux kernel vulnerability CVE-2026-68447 involves the drm/amdkfd driver where CRIU checkpointing copies the MQD control stack using a hardware-reported size without bounding it to the allocated buffer object (BO) size. If the hardware-reported size exceeds the allocated control stack size, memcpy reads beyond the BO into adjacent GTT memory, potentially leaking kernel data to userspace. The fix stores the page-aligned control stack BO size and clamps checkpoint copy sizes to the minimum of the hardware-reported size and the allocated size, including adjustments for multi-XCC v9.4.3 checkpoint layouts.

This vulnerability can lead to unintended disclosure of kernel memory contents to userspace processes, potentially exposing sensitive kernel data. There is no indication of code execution or privilege escalation. No known exploits in the wild have been reported.

A fix has been applied in the Linux kernel to clamp the checkpoint copy size to the allocated BO size, preventing out-of-bounds reads. Users should update to a kernel version that includes this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory or Linux kernel mailing lists for the exact fixed version and apply the update accordingly.