[PATCH V3 net-next 10/11] net: hns3: prevent double free in hns3_put_ring_config()

[Huazhong Tan]

This patch adds a check for the hns3_put_ring_config() to prevent
double free, and for more readable, move the NULL assignment of
priv->ring_data into the hns3_put_ring_config().

Signed-off-by: Huazhong Tan <tanhuazh...@huawei.com>
Signed-off-by: Peng Li <lipeng...@huawei.com>
---
 drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c 
b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index 7dc281c..b0f31eb 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -3487,6 +3487,7 @@ static int hns3_get_ring_config(struct hns3_nic_priv 
*priv)
        }
 
        devm_kfree(&pdev->dev, priv->ring_data);
+       priv->ring_data = NULL;
        return ret;
 }
 
@@ -3495,12 +3496,16 @@ static void hns3_put_ring_config(struct hns3_nic_priv 
*priv)
        struct hnae3_handle *h = priv->ae_handle;
        int i;
 
+       if (!priv->ring_data)
+               return;
+
        for (i = 0; i < h->kinfo.num_tqps; i++) {
                devm_kfree(priv->dev, priv->ring_data[i].ring);
                devm_kfree(priv->dev,
                           priv->ring_data[i + h->kinfo.num_tqps].ring);
        }
        devm_kfree(priv->dev, priv->ring_data);
+       priv->ring_data = NULL;
 }
 
 static int hns3_alloc_ring_memory(struct hns3_enet_ring *ring)
@@ -3920,8 +3925,6 @@ static void hns3_client_uninit(struct hnae3_handle 
*handle, bool reset)
 
        hns3_dbg_uninit(handle);
 
-       priv->ring_data = NULL;
-
 out_netdev_free:
        free_netdev(netdev);
 }
@@ -4268,12 +4271,10 @@ static int hns3_reset_notify_init_enet(struct 
hnae3_handle *handle)
        hns3_uninit_all_ring(priv);
 err_uninit_vector:
        hns3_nic_uninit_vector_data(priv);
-       priv->ring_data = NULL;
 err_dealloc_vector:
        hns3_nic_dealloc_vector_data(priv);
 err_put_ring:
        hns3_put_ring_config(priv);
-       priv->ring_data = NULL;
 
        return ret;
 }
@@ -4335,7 +4336,6 @@ static int hns3_reset_notify_uninit_enet(struct 
hnae3_handle *handle)
                netdev_err(netdev, "uninit ring error\n");
 
        hns3_put_ring_config(priv);
-       priv->ring_data = NULL;
 
        return ret;
 }
-- 
2.7.4