AMD General
Ping, Can I get a review on this change please? Kind regards, Vladimir From: Marioukhine, Vladimir Sent: Thursday, August 13, 2026 12:58 PM To: [email protected] Cc: Deucher, Alexander <[email protected]> Subject: [PATCH 1/2] drm/amdkfd: guard against NULL restore_mqd in CRIU queue restore 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, 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. Add a NULL guard for restore_mqd right after mqd_mgr is resolved, before any resource allocations, returning -EOPNOTSUPP if the callback is not implemented. This avoids complex error unwinding and is consistent with the existing checkpoint_mqd guard. Fixes: 48f0bdf4e38e ("drm/amdkfd: Added MQD manager files for GFX12.") Fixes: 01bbc4a4b947 ("drm/amdkfd: Add MQD manager for GFX 12.1.0") Cc: [email protected]<mailto:[email protected]> Signed-off-by: Vladimir Marioukhine <[email protected]<mailto:[email protected]>> --- drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c index ea9d87450eae..25b738200e7e 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -769,6 +769,11 @@ static int create_queue_nocpsch(struct device_queue_manager *dqm, 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) @@ -2134,6 +2139,11 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q, 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_sdma_queue; + } if (q->properties.type == KFD_QUEUE_TYPE_SDMA || q->properties.type == KFD_QUEUE_TYPE_SDMA_XGMI)
