[BUG]: `register()` accepts a mismatched UUID under `python -O`
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Description
Is this a duplicate?
- I confirmed there appear to be no duplicate issues for this bug and that I agree to the Code of Conduct
Type of Bug
Silent Failure
Component
cuda.core
Describe the bug
DeviceMemoryResource.register() and PinnedMemoryResource.register() check that the UUID they are given matches the resource's own with a bare assert in MP_register, so the check is absent whenever CPython runs with -O. The call then registers the resource under the other key and rewrites the resource's UUID, and mr.uuid reports the new value from then on.
How to Reproduce
import uuid
from cuda.core import Device, DeviceMemoryResource, DeviceMemoryResourceOptions
dev = Device(); dev.set_current()
mr = DeviceMemoryResource(dev, DeviceMemoryResourceOptions(ipc_enabled=True))
try:
mr.register(uuid.UUID("00000000-0000-0000-0000-000000000001"))
except AssertionError:
print("rejected")
else:
print("accepted, uuid is now", mr.uuid)
$ python repro.py
rejected
$ python -O repro.py
accepted, uuid is now 00000000-0000-0000-0000-000000000001
Expected behavior
register() should reject a UUID that is not the resource's own whether or not CPython was started with -O. Assertions are removed under -O, so the check as written does not exist in an optimized interpreter and the resource silently takes on the other key instead of raising.
Operating System
Ubuntu 26.04 LTS
nvidia-smi output
Tue Aug 25 15:01:31 2026
+-----------------------------------------------------------------------------------------+
| NVIDIA-SMI 595.84 Driver Version: 595.84 CUDA Version: 13.2 |
+-----------------------------------------+------------------------+----------------------+
| GPU Name Persistence-M | Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap | Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|=========================================+========================+======================|
| 0 NVIDIA GeForce RTX 3050 ... Off | 00000000:01:00.0 Off | N/A |
| N/A 59C P3 749W / 30W | 11MiB / 4096MiB | 8% Default |
| | | N/A |
+-----------------------------------------+------------------------+----------------------+
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with DeviceMemoryResource.register(), PinnedMemoryResource.register(), and the MP_register path described in the issue. Reproduce the mismatch with both python and python -O, then inspect the UUID check. Done means both entry points reject a mismatched UUID consistently and preserve the resource UUID.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Active
- Clarity
- Mostly clear
- Newbie friendliness
- 68/100