[PATCH net] xen-netfront: Add missing skb_mark_for_recycle

[Jesper Dangaard Brouer <hawk@xxxxxxxxxx>]

Notice that skb_mark_for_recycle() is introduced later than fixes tag in
6a5bcd84e886 ("page_pool: Allow drivers to hint on SKB recycling").

It is believed that fixes tag were missing a call to page_pool_release_page()
between v5.9 to v5.14, after which is should have used skb_mark_for_recycle().
Since v6.6 the call page_pool_release_page() were removed (in 535b9c61bdef
("net: page_pool: hide page_pool_release_page()") and remaining callers
converted (in commit 6bfef2ec0172 ("Merge branch
'net-page_pool-remove-page_pool_release_page'")).

This leak became visible in v6.8 via commit dba1b8a7ab68 ("mm/page_pool: catch
page_pool memory leaks").

Fixes: 6c5aa6fc4def ("xen networking: add basic XDP support for xen-netfront")
Reported-by: Arthur Borsboom <arthurborsboom@xxxxxxxxx>
Signed-off-by: Jesper Dangaard Brouer <hawk@xxxxxxxxxx>
---
Compile tested only, can someone please test this

 drivers/net/xen-netfront.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index ad29f370034e..8d2aee88526c 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -285,6 +285,7 @@ static struct sk_buff *xennet_alloc_one_rx_buffer(struct 
netfront_queue *queue)
                return NULL;
        }
        skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
+       skb_mark_for_recycle(skb);
 
        /* Align ip header to a 16 bytes boundary */
        skb_reserve(skb, NET_IP_ALIGN);