net/mlx5: Avoid dereferencing uninitialized pointer

In NETDEV_CHANGEUPPER event the upper_info field is valid
only when linking is true. Otherwise it should be ignored.

Fixes: 7907f23adc18 (net/mlx5: Implement RoCE LAG feature)
Signed-off-by: Talat Batheesh <talatb@mellanox.com>
Reviewed-by: Aviv Heller <avivh@mellanox.com>
Reviewed-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag.c b/drivers/net/ethernet/mellanox/mlx5/core/lag.c
index 55957246c0e844826a5a7f18c42c4678fb6c5be5..b5d5519542e87380b064de5578e327f0d55ba9cf 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/lag.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lag.c
@@ -294,7 +294,7 @@ static int mlx5_handle_changeupper_event(struct mlx5_lag *ldev,
                                         struct netdev_notifier_changeupper_info *info)
 {
        struct net_device *upper = info->upper_dev, *ndev_tmp;
-       struct netdev_lag_upper_info *lag_upper_info;
+       struct netdev_lag_upper_info *lag_upper_info = NULL;
        bool is_bonded;
        int bond_status = 0;
        int num_slaves = 0;
@@ -303,7 +303,8 @@ static int mlx5_handle_changeupper_event(struct mlx5_lag *ldev,
        if (!netif_is_lag_master(upper))
                return 0;
 
-       lag_upper_info = info->upper_info;
+       if (info->linking)
+               lag_upper_info = info->upper_info;
 
        /* The event may still be of interest if the slave does not belong to
         * us, but is enslaved to a master which has one or more of our netdevs