Re: [PATCH v2] rtl8187: Fix potential buffer underflow in rtl8187_rx_cb()

[Markus Elfring]

…
> +++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
> @@ -344,8 +344,13 @@ static void rtl8187_rx_cb(struct urb *urb)
>  	}
>  
>  	if (!priv->is_rtl8187b) {
> -		struct rtl8187_rx_hdr *hdr =
> -			(typeof(hdr))(skb_tail_pointer(skb) - sizeof(*hdr));
> +		struct rtl8187_rx_hdr *hdr;
> +
> +		if (skb->len < sizeof(struct rtl8187_rx_hdr)) {
> +			dev_kfree_skb_irq(skb);
> +			return;
> +		}
…

You may avoid duplicate exception handling code by using a corresponding goto statement.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?h=v6.18-rc5#n526

Regards,
Markus