Re: [PATCH net v3 2/2] net: ethernet: oa_tc6: fix tx skb race condition between reference pointers

[Jakub Kicinski]

On Wed, 4 Dec 2024 19:05:18 +0530 Parthiban Veerasooran wrote:
> @@ -1210,7 +1213,9 @@ netdev_tx_t oa_tc6_start_xmit(struct oa_tc6 *tc6, struct sk_buff *skb)
>  		return NETDEV_TX_OK;
>  	}
>  
> +	mutex_lock(&tc6->tx_skb_lock);
>  	tc6->waiting_tx_skb = skb;
> +	mutex_unlock(&tc6->tx_skb_lock);

start_xmit runs in BH / softirq context. You can't take sleeping locks.
The lock has to be a spin lock. You could possibly try to use the
existing spin lock of the tx queue (__netif_tx_lock()) but that may be
more challenging to do cleanly from within a library..

Please make sure you test with builds including the
kernel/configs/debug.config Kconfigs.
-- 
pw-bot: cr