Re: [PATCH net-next v2] net: dsa: Fix skb ownership in taggers

[Qingfang Deng <qingfang.deng@linux.dev>]

On 16 Jun 2026 at 11:36:22 +0200, Linus Walleij wrote:
> --- a/net/dsa/tag_rtl4_a.c
> +++ b/net/dsa/tag_rtl4_a.c
> @@ -41,8 +41,10 @@ static struct sk_buff *rtl4a_tag_xmit(struct sk_buff *skb,
>  	u16 out;
>  
>  	/* Pad out to at least 60 bytes */
> -	if (unlikely(__skb_put_padto(skb, ETH_ZLEN, false)))
> +	if (unlikely(__skb_put_padto(skb, ETH_ZLEN, false))) {
> +		kfree_skb(skb);
>  		return NULL;
> +	}

This can be simplified to eth_skb_pad().

>  
>  	netdev_dbg(dev, "add realtek tag to package to port %d\n",
>  		   dp->index);
> --- a/net/dsa/tag_rzn1_a5psw.c
> +++ b/net/dsa/tag_rzn1_a5psw.c
> @@ -48,7 +48,7 @@ static struct sk_buff *a5psw_tag_xmit(struct sk_buff *skb, struct net_device *de
>  	 * least 60 bytes otherwise they will be discarded when they enter the
>  	 * switch port logic.
>  	 */
> -	if (__skb_put_padto(skb, ETH_ZLEN, false))
> +	if (skb_put_padto(skb, ETH_ZLEN))
>  		return NULL;

Same here.

>  
>  	/* provide 'A5PSW_TAG_LEN' bytes additional space */

- Qingfang