Re: [PATCH net 1/2] virtio_net: check AF_XDP queue index before use

On Thu, Aug 06, 2026 at 09:04:10AM -0700, Jakub Kicinski wrote:
> Was an out of range qid actually reachable here?
> ...
> Could the changelog describe this as a defensive reordering rather than
> as preventing an out of range dereference?
> ...
> since the patch touches the enable-side qid test, is the symmetric test
> in virtnet_xsk_pool_disable() safe?

Thanks for the review.

You are right on both counts for this patch: qid is already bounded by
xsk_reg_pool_at_qid(), and the old ordering still rejected the request
before sq/rq were used.  The only visible difference was -EINVAL vs
-ENOENT for qid in [curr_queue_pairs, max_queue_pairs).  I will drop
this reorder (and the overstated changelog).

On the disable path / XDP detach interaction: I agree.  If
curr_queue_pairs shrinks while an AF_XDP pool is still bound,
virtnet_xsk_pool_disable() can return -EINVAL, skip cleanup, and leave
rq/sq->xsk_pool pointing at a pool that xp_clear_dev() then frees.

I will drop this series and post a v2 replacement as a new thread that:
1) lets disable clean up with a max_queue_pairs bounds check, and
2) refuses XDP-driven queue shrink while AF_XDP is still bound.

Thanks,
Xiong Weimin