CVE-2026-64263

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

fuse-uring: fix moving cancelled entry to entinuserspace list

fuseuringcancel() moves entries that are available (these have no reqs attached) to the entinuserspace list. entlistrequestexpired() checks the first entry on entinuserspace and dereferences ent->fusereq unconditionally, which will crash on a cancelled entry that was moved to this list.

Fix this by freeing the entry and dropping queuerefs directly in fuseuringcancel(). This is safe because cancel is the cancel handler itself - after iouringcmddone(), no more cancels will be dispatched for this command, and teardown serializes with cancel via queue->lock.

Since cancel now decrements queuerefs, fuseuringabort() must no longer gate fuseuringabortendrequests() on queuerefs > 0, as cancelled entries may have already dropped queue_refs while requests are still queued. Remove the gate so abort always flushes requests and stops queues.