netvsc: unshare skb in VF rx handler

[ Upstream commit 996ed04741467f6d1552440c92988b132a9487ec ]

The netvsc VF skb handler should make sure that skb is not
shared. Similar logic already exists in bonding and team device
drivers.

This is not an issue in practice because the VF devicex
does not send up shared skb's. But the netvsc driver
should do the right thing if it did.

Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 1f9f7fcdb0eb363ab9bbb57c0a00a1f235d38807..54670c9905c79e00fa197df916920d4fc3582f88 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2004,6 +2004,12 @@ static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb)
        struct netvsc_vf_pcpu_stats *pcpu_stats
                 = this_cpu_ptr(ndev_ctx->vf_stats);
 
+       skb = skb_share_check(skb, GFP_ATOMIC);
+       if (unlikely(!skb))
+               return RX_HANDLER_CONSUMED;
+
+       *pskb = skb;
+
        skb->dev = ndev;
 
        u64_stats_update_begin(&pcpu_stats->syncp);