[PATCH] staging: rtl8188eu: fix possible null dereference

[PATCH] staging: rtl8188eu: fix possible null dereference

[Connor Kuehl]

Inside a nested 'else' block at the beginning of this function is a
call that assigns 'psta' to the return value of 'rtw_get_stainfo()'.
If 'rtw_get_stainfo()' returns NULL and the flow of control reaches
the 'else if' where 'psta' is dereferenced, then we will dereference
a NULL pointer.

Fix this by checking if 'psta' is not NULL before reading its
'psta->qos_option' data member.

Addresses-Coverity: ("Dereference null return value")

Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
---
 drivers/staging/rtl8188eu/core/rtw_xmit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_xmit.c b/drivers/staging/rtl8188eu/core/rtw_xmit.c
index 952f2ab51347..bf8877cbe9b6 100644
--- a/drivers/staging/rtl8188eu/core/rtw_xmit.c
+++ b/drivers/staging/rtl8188eu/core/rtw_xmit.c
@@ -784,7 +784,7 @@ s32 rtw_make_wlanhdr(struct adapter *padapter, u8 *hdr, struct pkt_attrib *pattr
 			memcpy(pwlanhdr->addr2, pattrib->src, ETH_ALEN);
 			memcpy(pwlanhdr->addr3, get_bssid(pmlmepriv), ETH_ALEN);
 
-			if (psta->qos_option)
+			if (psta && psta->qos_option)
 				qos_option = true;
 		} else {
 			RT_TRACE(_module_rtl871x_xmit_c_, _drv_err_, ("fw_state:%x is not allowed to xmit frame\n", get_fwstate(pmlmepriv)));
-- 
2.17.1

Re: [PATCH] staging: rtl8188eu: fix possible null dereference

[Larry Finger]

On 9/25/19 4:32 PM, Connor Kuehl wrote:
> Inside a nested 'else' block at the beginning of this function is a
> call that assigns 'psta' to the return value of 'rtw_get_stainfo()'.
> If 'rtw_get_stainfo()' returns NULL and the flow of control reaches
> the 'else if' where 'psta' is dereferenced, then we will dereference
> a NULL pointer.
> 
> Fix this by checking if 'psta' is not NULL before reading its
> 'psta->qos_option' data member.
> 
> Addresses-Coverity: ("Dereference null return value")
> 
> Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
> ---
>   drivers/staging/rtl8188eu/core/rtw_xmit.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rtl8188eu/core/rtw_xmit.c b/drivers/staging/rtl8188eu/core/rtw_xmit.c
> index 952f2ab51347..bf8877cbe9b6 100644
> --- a/drivers/staging/rtl8188eu/core/rtw_xmit.c
> +++ b/drivers/staging/rtl8188eu/core/rtw_xmit.c
> @@ -784,7 +784,7 @@ s32 rtw_make_wlanhdr(struct adapter *padapter, u8 *hdr, struct pkt_attrib *pattr
>   			memcpy(pwlanhdr->addr2, pattrib->src, ETH_ALEN);
>   			memcpy(pwlanhdr->addr3, get_bssid(pmlmepriv), ETH_ALEN);
>   
> -			if (psta->qos_option)
> +			if (psta && psta->qos_option)
>   				qos_option = true;
>   		} else {
>   			RT_TRACE(_module_rtl871x_xmit_c_, _drv_err_, ("fw_state:%x is not allowed to xmit frame\n", get_fwstate(pmlmepriv)));
> 

This change is a good one, but why not get the same fix at line 779?

Larry

Re: [PATCH] staging: rtl8188eu: fix possible null dereference

[Connor Kuehl]

On 9/25/19 5:05 PM, Larry Finger wrote:
> This change is a good one, but why not get the same fix at line 779?

Ah yes! Thanks for pointing that out. I missed that. I will send a V2 
shortly.

Thank you,

Connor

> 
> Larry
> 

[PATCH] staging: rtl8188eu: fix possible NULL dereference

[Sudip Mukherjee]

dm_odm was being checked for NULL after dereferencing it. Lets check for
NULL first before derefenrencing it.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---
 drivers/staging/rtl8188eu/hal/Hal8188ERateAdaptive.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/rtl8188eu/hal/Hal8188ERateAdaptive.c b/drivers/staging/rtl8188eu/hal/Hal8188ERateAdaptive.c
index 15a1765..2633a13 100644
--- a/drivers/staging/rtl8188eu/hal/Hal8188ERateAdaptive.c
+++ b/drivers/staging/rtl8188eu/hal/Hal8188ERateAdaptive.c
@@ -659,11 +659,11 @@ void ODM_RA_UpdateRateInfo_8188E(struct odm_dm_struct *dm_odm, u8 macid, u8 Rate
 {
 	struct odm_ra_info *pRaInfo = NULL;
 
+	if ((NULL == dm_odm) || (macid >= ASSOCIATE_ENTRY_NUM))
+		return;
 	ODM_RT_TRACE(dm_odm, ODM_COMP_RATE_ADAPTIVE, ODM_DBG_LOUD,
 		     ("macid =%d RateID = 0x%x RateMask = 0x%x SGIEnable =%d\n",
 		     macid, RateID, RateMask, SGIEnable));
-	if ((NULL == dm_odm) || (macid >= ASSOCIATE_ENTRY_NUM))
-		return;
 
 	pRaInfo = &(dm_odm->RAInfo[macid]);
 	pRaInfo->RateID = RateID;
@@ -676,10 +676,10 @@ void ODM_RA_SetRSSI_8188E(struct odm_dm_struct *dm_odm, u8 macid, u8 Rssi)
 {
 	struct odm_ra_info *pRaInfo = NULL;
 
-	ODM_RT_TRACE(dm_odm, ODM_COMP_RATE_ADAPTIVE, ODM_DBG_TRACE,
-		     (" macid =%d Rssi =%d\n", macid, Rssi));
 	if ((NULL == dm_odm) || (macid >= ASSOCIATE_ENTRY_NUM))
 		return;
+	ODM_RT_TRACE(dm_odm, ODM_COMP_RATE_ADAPTIVE, ODM_DBG_TRACE,
+		     (" macid =%d Rssi =%d\n", macid, Rssi));
 
 	pRaInfo = &(dm_odm->RAInfo[macid]);
 	pRaInfo->RssiStaRA = Rssi;
-- 
1.9.1