[PATCH 4.9 04/51] mlxsw: switchx2: Fix memory leak at skb reallocation

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Arkadi Sharshevsky <arkadis@xxxxxxxxxxxx>


[ Upstream commit 400fc0106dd8c27ed84781c929c1a184785b9c79 ]

During transmission the skb is checked for headroom in order to
add vendor specific header. In case the skb needs to be re-allocated,
skb_realloc_headroom() is called to make a private copy of the original,
but doesn't release it. Current code assumes that the original skb is
released during reallocation and only releases it at the error path
which causes a memory leak.

Fix this by adding the original skb release to the main path.

Fixes: d003462a50de ("mlxsw: Simplify mlxsw_sx_port_xmit function")
Signed-off-by: Arkadi Sharshevsky <arkadis@xxxxxxxxxxxx>
Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlxsw/switchx2.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/net/ethernet/mellanox/mlxsw/switchx2.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/switchx2.c
@@ -314,6 +314,7 @@ static netdev_tx_t mlxsw_sx_port_xmit(st
 			dev_kfree_skb_any(skb_orig);
 			return NETDEV_TX_OK;
 		}
+		dev_consume_skb_any(skb_orig);
 	}
 	mlxsw_sx_txhdr_construct(skb, &tx_info);
 	/* TX header is consumed by HW on the way so we shouldn't count its