[PATCH 8/9] ethdev: keep fast-path ops valid after port stop

[Morten Brørup]

> From: Maxime Leroy [mailto:maxime.leroys at gmail.com] On Behalf Of Maxime
> Leroy
> Sent: Thursday, 11 June 2026 17.49
> 
> eth_dev_fp_ops_reset() restores a port's fast-path ops on stop/release
> via a compound literal, so every field it omits is zeroed to NULL. It
> sets only rx_pkt_burst/tx_pkt_burst (and the rxq/txq data), leaving
> rx_queue_count, tx_queue_count, rx/tx_descriptor_status, tx_pkt_prepare
> and the recycle callbacks NULL.
> 
> In non-debug builds these ops are reached through an unguarded indirect
> call (the NULL check exists only under RTE_ETHDEV_DEBUG_RX/TX). So a
> thread calling e.g. rte_eth_rx_queue_count() on a port being stopped
> dereferences NULL and crashes, while the same race on
> rte_eth_rx_burst()
> is harmless because the burst ops are reset to dummies. A poll-mode
> worker re-checking rx_queue_count before arming the Rx interrupt and
> sleeping hits exactly this.
> 
> Reset these ops to the same dummies eth_dev_set_dummy_fops() installs,
> so a stopped port behaves like a freshly allocated one: every fast-path
> op is a safe no-op, none is NULL.
> 
> Fixes: 066f3d9cc21c ("ethdev: remove callback checks from fast path")
> Cc: stable at dpdk.org
> Signed-off-by: Maxime Leroy <maxime at leroys.fr>
> ---

Good catch.
Acked-by: Morten Brørup <mb at smartsharesystems.com>

Not related to the series, consider sending as separate patch.