[PATCH 2/4] ath10k: make sure to not use invalid beacon pointer

[Kalle Valo]

Michal Kazior <michal.kazior at tieto.com> writes:

> If DMA mapping of next beacon failed it was
> possible for next SWBA to access a pointer that
> was already unmapped and freed. This could cause
> memory corruption.
>
> Signed-off-by: Michal Kazior <michal.kazior at tieto.com>
> ---
>  drivers/net/wireless/ath/ath10k/wmi.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
> index d4b48ef..35c7d52 100644
> --- a/drivers/net/wireless/ath/ath10k/wmi.c
> +++ b/drivers/net/wireless/ath/ath10k/wmi.c
> @@ -1441,6 +1441,8 @@ static void ath10k_wmi_event_host_swba(struct ath10k *ar, struct sk_buff *skb)
>  			dev_kfree_skb_any(arvif->beacon);
>  		}
>  
> +		arvif->beacon = NULL;

Why have this outside the "if (arvif->beacon)" check? If it's already
NULL, there's no need to set it to NULL again. And besides, at least for
me, it's more intuitive to reset the variable immeadiately after
dev_kfree_skb_any().

-- 
Kalle Valo