6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vladimir Marioukhine commit 6aa530642f95d5c48aa336416f94a35e7949b647 upstream. Both create_queue_cpsch() and create_queue_nocpsch() unconditionally call mqd_mgr->restore_mqd() when a CRIU restore is in progress (qd != NULL), with no NULL guard. On any system where restore_mqd is not implemented for the given queue type, a user holding CAP_CHECKPOINT_RESTORE can trigger a kernel NULL pointer dereference and panic the machine by issuing KFD_IOC_CRIU_OP_RESTORE with a crafted queue restore object. Note that checkpoint_mqd is likewise unimplemented on GFX12, so no legitimate CRIU image can reach this path — only a hand-crafted restore payload. Add a NULL guard for restore_mqd immediately after mqd_mgr is resolved, unwinding via the existing error labels and returning -EOPNOTSUPP if the callback is not implemented. This mirrors the existing checkpoint_mqd guard in checkpoint_mqd(). Fixes: 48f0bdf4e38e ("drm/amdkfd: Added MQD manager files for GFX12.") Cc: stable@vger.kernel.org Signed-off-by: Vladimir Marioukhine Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -653,6 +653,11 @@ static int create_queue_nocpsch(struct d mqd_mgr = dqm->mqd_mgrs[get_mqd_type_from_queue_type( q->properties.type)]; + if (qd && !mqd_mgr->restore_mqd) { + pr_debug("restore_mqd not implemented for this GPU\n"); + retval = -EOPNOTSUPP; + goto deallocate_vmid; + } if (q->properties.type == KFD_QUEUE_TYPE_COMPUTE) { retval = allocate_hqd(dqm, q); if (retval) @@ -2002,6 +2007,11 @@ static int create_queue_cpsch(struct dev mqd_mgr = dqm->mqd_mgrs[get_mqd_type_from_queue_type( q->properties.type)]; + if (qd && !mqd_mgr->restore_mqd) { + pr_debug("restore_mqd not implemented for this GPU\n"); + retval = -EOPNOTSUPP; + goto out_deallocate_doorbell; + } if (q->properties.type == KFD_QUEUE_TYPE_SDMA || q->properties.type == KFD_QUEUE_TYPE_SDMA_XGMI)