Subject: [net 07/16] net/mlx5e: Fix null deref accessing lag dev

From: Saeed Mahameed <[email-masked]>
Date: Tue, 18 May 2021 23:05:14 -0700

From: Roi Dayan <[email-masked]>

It could be the lag dev is null so stop processing the event.
In bond_enslave() the active/backup slave being set before setting the
upper dev so first event is without an upper dev.
After setting the upper dev with bond_master_upper_dev_link() there is
a second event and in that event we have an upper dev.

Fixes: 7e51891a237f ("net/mlx5e: Use netdev events to set/del egress acl forward-to-vport rule")
Signed-off-by: Roi Dayan <[email-masked]>
Reviewed-by: Maor Dickman <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/rep/bond.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/rep/bond.c b/drivers/net/ethernet/mellanox/mlx5/core/en/rep/bond.c
index 95f2b26a3ee3..9c076aa20306 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/rep/bond.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/rep/bond.c
@@ -223,6 +223,8 @@ static void mlx5e_rep_changelowerstate_event(struct net_device *netdev, void *pt
 	rpriv = priv->ppriv;
 	fwd_vport_num = rpriv->rep->vport;
 	lag_dev = netdev_master_upper_dev_get(netdev);
+	if (!lag_dev)
+		return;
 
 	netdev_dbg(netdev, "lag_dev(%s)'s slave vport(%d) is txable(%d)\n",
 		   lag_dev->name, fwd_vport_num, net_lag_port_dev_txable(netdev));
-- 
2.31.1