From f020bb63b5d2e5576acadd10e158fe3b04af67ba Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang@redhat.com>
Date: Fri, 17 Sep 2021 16:34:06 +0800
Subject: [PATCH] virtio-net: fix pages leaking when building skb in big mode
Git-commit: afd92d82c9d715fb97565408755acad81573591a
Patch-mainline: v5.15-rc3
References: stable-5.14.9
 
[ Upstream commit afd92d82c9d715fb97565408755acad81573591a ]
 
We try to use build_skb() if we had sufficient tailroom. But we forget
to release the unused pages chained via private in big mode which will
leak pages. Fixing this by release the pages after building the skb in
big mode.
 
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
 
---
 drivers/net/virtio_net.c | 4 ++++
 1 file changed, 4 insertions(+)
 
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index eee493685aad..fb96658bb91f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -435,6 +435,10 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 
 		skb_reserve(skb, p - buf);
 		skb_put(skb, len);
+
+		page = (struct page *)page->private;
+		if (page)
+			give_pages(rq, page);
 		goto ok;
 	}
 
-- 
2.26.2