Re: [syzbot] [io-uring?] [net?] WARNING: refcount bug in zcrx_unregister_user

[Edward Adam Davis]

#syz test

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index f1464ea8ca64..75f799f20818 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -550,6 +550,7 @@ static struct io_zcrx_ifq *io_zcrx_ifq_alloc(struct io_ring_ctx *ctx)
 
 static void io_zcrx_drop_netdev(struct io_zcrx_ifq *ifq)
 {
+	BUG_ON(ifq);
 	guard(mutex)(&ifq->pp_lock);
 
 	if (!ifq->netdev)
@@ -567,6 +568,7 @@ static void io_close_queue(struct io_zcrx_ifq *ifq)
 		.mp_priv = ifq,
 	};
 
+	printk("ifq: %p, %s\n", ifq, __func__);
 	scoped_guard(mutex, &ifq->pp_lock) {
 		netdev = ifq->netdev;
 		netdev_tracker = ifq->netdev_tracker;