Subject: Re: [PATCH net] sfc: fix potential memleak in __ef100_hard_start_xmit()

From: Leon Romanovsky <[email-masked]>
Date: Thu, 17 Nov 2022 13:36:21 +0200

On Thu, Nov 17, 2022 at 03:50:09PM +0800, Zhang Changzhong wrote:
> The __ef100_hard_start_xmit() returns NETDEV_TX_OK without freeing skb
> in error handling case, add dev_kfree_skb_any() to fix it.
> 
> Fixes: 51b35a454efd ("sfc: skeleton EF100 PF driver")
> Signed-off-by: Zhang Changzhong <[email-masked]>
> ---
>  drivers/net/ethernet/sfc/ef100_netdev.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/ethernet/sfc/ef100_netdev.c b/drivers/net/ethernet/sfc/ef100_netdev.c
> index 88fa295..ddcc325 100644
> --- a/drivers/net/ethernet/sfc/ef100_netdev.c
> +++ b/drivers/net/ethernet/sfc/ef100_netdev.c
> @@ -218,6 +218,7 @@ netdev_tx_t __ef100_hard_start_xmit(struct sk_buff *skb,
>  		   skb->len, skb->data_len, channel->channel);
>  	if (!efx->n_channels || !efx->n_tx_channels || !channel) {
>  		netif_stop_queue(net_dev);
> +		dev_kfree_skb_any(skb);
>  		goto err;
>  	}

ef100 doesn't release in __ef100_enqueue_skb() either. SKB shouldn't be
NULL or ERR at this stage.

diff --git a/drivers/net/ethernet/sfc/ef100_tx.c b/drivers/net/ethernet/sfc/ef100_tx.c
index 29ffaf35559d..426706b91d02 100644
--- a/drivers/net/ethernet/sfc/ef100_tx.c
+++ b/drivers/net/ethernet/sfc/ef100_tx.c
@@ -497,7 +497,7 @@ int __ef100_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb,

 err:
        efx_enqueue_unwind(tx_queue, old_insert_count);
-       if (!IS_ERR_OR_NULL(skb))
+       if (rc)
                dev_kfree_skb_any(skb);

        /* If we're not expecting another transmit and we had something to push

> -- 
> 2.9.5