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

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

[Haowen Bai]

The ieee80211_check_auth_response() function has a signedness bug because
it's a declared as a u16 but it return -ENOMEM.  When you look at it more
closely it returns a mix of error codes including 0xcafe, -ENOMEM, and
a->status which is WLAN_STATUS_NOT_SUPPORTED_AUTH_ALG.  This is a mess.

Clean it up to just return standard kernel error codes.  We can print
out the a->status before returning a regular error code.  The printks
in the caller need to be adjusted as well.

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
---
 drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
index 4e8fbd2410a1..dfe57748a70e 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
@@ -1461,13 +1461,13 @@ 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 int auth_parse(struct sk_buff *skb, u8 **challenge, int *chlen)
 {
 	struct ieee80211_authentication *a;
 	u8 *t;
 	if (skb->len < (sizeof(struct ieee80211_authentication) - sizeof(struct ieee80211_info_element))) {
 		IEEE80211_DEBUG_MGMT("invalid len in auth resp: %d\n", skb->len);
-		return 0xcafe;
+		return -EINVAL;
 	}
 	*challenge = NULL;
 	a = (struct ieee80211_authentication *)skb->data;
@@ -1482,7 +1482,12 @@ static inline u16 auth_parse(struct sk_buff *skb, u8 **challenge, int *chlen)
 		}
 	}
 
-	return le16_to_cpu(a->status);
+	if (a->status) {
+		IEEE80211_DEBUG_MGMT("auth_parse() failed\n");
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
 static int auth_rq_parse(struct sk_buff *skb, u8 *dest)
@@ -1829,7 +1834,7 @@ static void ieee80211_check_auth_response(struct ieee80211_device *ieee,
 {
 	/* default support N mode, disable halfNmode */
 	bool bSupportNmode = true, bHalfSupportNmode = false;
-	u16 errcode;
+	int errcode;
 	u8 *challenge;
 	int chlen = 0;
 	u32 iotAction;
@@ -1878,7 +1883,7 @@ static void ieee80211_check_auth_response(struct ieee80211_device *ieee,
 		}
 	} else {
 		ieee->softmac_stats.rx_auth_rs_err++;
-		IEEE80211_DEBUG_MGMT("Auth response status code 0x%x", errcode);
+		IEEE80211_DEBUG_MGMT("Auth response status code %d\n", errcode);
 		ieee80211_associate_abort(ieee);
 	}
 }
-- 
2.7.4

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

[Dan Carpenter]

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

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

[Haowen Bai]

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;
@@ -1826,7 +1826,7 @@ static void ieee80211_check_auth_response(struct ieee80211_device *ieee,
 {
 	/* default support N mode, disable halfNmode */
 	bool bSupportNmode = true, bHalfSupportNmode = false;
-	u16 errcode;
+	s16 errcode;
 	u8 *challenge;
 	int chlen = 0;
 	u32 iotAction;
-- 
2.7.4