In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix OOB memory exposure in get_wave_state() The get_wave_state() function for v9 trusts cp_hqd_cntl_stack_size and cp_hqd_cntl_stack_offset values read dir…

Overview

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

drm/amdkfd: Fix OOB memory exposure in get_wave_state()

The get_wave_state() function for v9 trusts cp_hqd_cntl_stack_size and cp_hqd_cntl_stack_offset values read directly from the MQD, which are written by GPU microcode and fully attacker-controlled on the CRIU-restore path (via AMDKFD_IOC_RESTORE_PROCESS with H3).

this leads to an unbounded copy_to_user() that can leak adjacent GTT/kernel memory. If offset > size, integer underflow produces a ~4 GiB read length, if size is set to 1 MiB against a 4 KiB allocation, we leak 1 MiB of adjacent kernel memory (other queues' MQDs, ring buffers, KASLR pointers).

Fix by clamping both cp_hqd_cntl_stack_size to the actual allocated buffer size (q->ctl_stack_size) and cp_hqd_cntl_stack_offset to the clamped size before performing arithmetic and copy_to_user().

This ensures we never read beyond the allocated kernel BO regardless of attacker-supplied MQD field values.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-30 · vex