NULL pointer deref of partially uninitialized uvm_parent_gpu_t in error path

[sdimitro]

Relevant Tickets:

• NVIDIA ID: 5610224
• CoreWeave ID: 789

We first hit this in the 570 releases and it seems like it hasn't been fixed in the 580 ones either.

Control flow that triggers the issue:

uvm_ioctl
  -> uvm_api_register_gpu
    -> uvm_va_space_register_gpu
      -> uvm_gpu_retain_by_uuid
        -> gpu_retain_by_uuid_locked
          -> add_gpu
            -> alloc_parent_gpu
              ** allocated parent_gpu but didn't initialize parent_gpu->pci_dev yet **
            <- alloc_parent_gpu
            ...
            -> init_parent_gpu
              ** returns error before initializing parent_gpu->pci_dev **
            <- ini_parent_gpu
            -> remove_gpu
              ...
              -> deinit_gpu
                ...
                -> uvm_pmm_gpu_device_p2p_deinit
                  -> uvm_device_p2p_static_bar
                    ** dereferences gpu->parent->pci_dev and crashes the system **

[CLAassistant]

All committers have signed the CLA.