Re: [PATCH] wifi: brcmfmac: Fix allocation size

[Simon Horman <simon.horman@corigine.com>]

On Tue, Jan 17, 2023 at 01:45:08PM +0300, Alexey V. Vissarionov wrote:
> The "pkt" is a pointer to struct sk_buff, so it's just 4 or 8
> bytes, while the structure itself is much bigger.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: bbd1f932e7c45ef1 ("brcmfmac: cleanup ampdu-rx host reorder code")
> Signed-off-by: Alexey V. Vissarionov <gremlin@altlinux.org>
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
> index 36af81975855c525..0d283456da331464 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
> @@ -1711,7 +1711,7 @@ void brcmf_fws_rxreorder(struct brcmf_if *ifp, struct sk_buff *pkt)
>  		buf_size = sizeof(*rfi);
>  		max_idx = reorder_data[BRCMF_RXREORDER_MAXIDX_OFFSET];
>  
> -		buf_size += (max_idx + 1) * sizeof(pkt);
> +		buf_size += (max_idx + 1) * sizeof(struct sk_buff);
>  
>  		/* allocate space for flow reorder info */
>  		brcmf_dbg(INFO, "flow-%d: start, maxidx %d\n",

Hi Alexey,

This is followed by:

		rfi = kzalloc(buf_size, GFP_ATOMIC);
		...
		rfi->pktslots = (struct sk_buff **)(rfi + 1);

The type of rfi is struct brcmf_ampdu_rx_reorder, which looks like this:

struct brcmf_ampdu_rx_reorder {
        struct sk_buff **pktslots;                                       
	...
};

And it looks to me that pkt is used as an array of (struct sk_buff *).

So in all, it seems to me that the current code is correct.

Is there a particular code that leads you to think otherwise?

Kind regards,
Simon