[PATCH net-next 3/3] net/mlx5e: use skb_share_check() in the loopback selftest hook

[Nicolai Buchwitz]

The loopback hook gets a shared skb when another ETH_P_IP handler is
bound to the device. skb_linearize() on a non-linear frame then hits
BUG_ON(skb_shared()).

Call skb_share_check() before linearizing the skb.

Fixes: 95b9606b15bb ("net/mlx5: Extend Ethtool loopback selftest to support non-linear SKB")
Signed-off-by: Nicolai Buchwitz <nb at tipi-net.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c b/drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c
index 1dcdb86690bb..8eb9a9469549 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c
@@ -166,6 +166,10 @@ mlx5e_test_loopback_validate(struct sk_buff *skb,
 	struct udphdr *udph;
 	struct iphdr *iph;
 
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		goto out;
+
 	if (skb_linearize(skb))
 		goto out;
 

-- 
2.53.0