Re: [PATCH] Staging: rtl8192u: Fix signedness bug in ieee80211_check_auth_response()

[Dan Carpenter <dan.carpenter@oracle.com>]

On Thu, Apr 14, 2022 at 06:32:12PM +0800, Haowen Bai wrote:
> function ieee80211_check_auth_response () unsigned errcode receive auth_parse()'s
> errcode -ENOMEM.
> 
> Signed-off-by: Haowen Bai <baihaowen@meizu.com>
> ---
>  drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
> index 1a43979939a8..4d060c3ec077 100644
> --- a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
> +++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
> @@ -1461,7 +1461,7 @@ void ieee80211_softmac_check_all_nets(struct ieee80211_device *ieee)
>  	spin_unlock_irqrestore(&ieee->lock, flags);
>  }
>  
> -static inline u16 auth_parse(struct sk_buff *skb, u8 **challenge, int *chlen)
> +static inline s16 auth_parse(struct sk_buff *skb, u8 **challenge, int *chlen)
>  {
>  	struct ieee80211_authentication *a;
>  	u8 *t;


The auth_parse() function returns 0xcafe on error or else it returns
-ENOMEM or it returns WLAN_STATUS_NOT_SUPPORTED_AUTH_ALG (13).  It
returns zero on success.  It's a bit silly to return all these random
things.  It should only return normal kernel error codes.

If we want we could make it print its own error message:

	if (a->status) {
		netdev_info(dev, "Authentication response status code 0x%x",
			    le16_to_cpu(a->status))
		return -EINVAL;
	}

	return 0;

Then delete the printk in the caller or modify it to print an %d instead
of the error code in hex.

regards,
dan carpenter