CVE-2026-64263

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

fuse-uring: fix moving cancelled entry to ent_in_userspace list

fuse_uring_cancel() moves entries that are available (these have no reqs

attached) to the ent_in_userspace list. ent_list_request_expired()

checks the first entry on ent_in_userspace and dereferences

ent->fuse_req unconditionally, which will crash on a cancelled entry

that was moved to this list.

Fix this by freeing the entry and dropping queue_refs directly in

fuse_uring_cancel(). This is safe because cancel is the cancel handler

itself - after io_uring_cmd_done(), no more cancels will be dispatched

for this command, and teardown serializes with cancel via queue->lock.

Since cancel now decrements queue_refs, fuse_uring_abort() must no

longer gate fuse_uring_abort_end_requests() on queue_refs > 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.