CVE-2026-64259

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

fuse-uring: make a fuse_req on SQE commit only findable after memcpy

Bad userspace might try to trick us and send commit SQEs request

unique / commit-id of requests that are not even send to

fuse-server (io_uring_cmd_done() not called) yet.

fuse_uring_commit_fetch() ends the fuse request when the ring entry

has a wrong state, but that could have caused a use-after-free

with the memcpy operations in fuse_uring_send_in_task().

In order to avoid such races the call of fuse_uring_add_to_pq()

is moved after the copy operations and just before completing

the io-uring request - malicious userspace cannot find the request

anymore until all prepration work in fuse-client/kernel is completed.

This also moves fuse_uring_add_to_pq() a bit up in the code to

avoid a forward declaration. Also not with a preparation commit,

to make it easier to back port to older kernels.