Re: [PATCH net-next] eth: bnxt: fix deadlock when xdp is attached or detached

On Tue, May 20, 2025 at 12:12 AM Taehee Yoo [off-list ref] wrote:

When xdp is attached or detached, dev->ndo_bpf() is called by
do_setlink(), and it acquires netdev_lock() if needed.
Unlike other drivers, the bnxt driver is protected by netdev_lock while
xdp is attached/detached because it sets dev->request_ops_lock to true.

So, the bnxt_xdp(), that is callback of ->ndo_bpf should not acquire
netdev_lock().
But the xdp_features_{set | clear}_redirect_target() was changed to
acquire netdev_lock() internally.
It causes a deadlock.
To fix this problem, bnxt driver should use
xdp_features_{set | clear}_redirect_target_locked() instead.

Thanks.
Reviewed-by: Michael Chan <michael.chan@broadcom.com>