[patch 2/2 v2] Staging: rtl8192e: pointer math bug in rtllib_rx_DELBA()

[patch 2/2 v2] Staging: rtl8192e: pointer math bug in rtllib_rx_DELBA()

[Dan Carpenter]

The pointer math here was totally wrong so we were reading nonsense
information from beyond the end of the buffer.  It could lead to an oops
if that memory wasn't mapped.

The "pReasonCode" pointer is assigned but never used so I deleted it.

With-Fix-From: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: Mateusz noticed some more pointer math bugs on the next lines.

diff --git a/drivers/staging/rtl8192e/rtl819x_BAProc.c b/drivers/staging/rtl8192e/rtl819x_BAProc.c
index 60f536c..78ede4a 100644
--- a/drivers/staging/rtl8192e/rtl819x_BAProc.c
+++ b/drivers/staging/rtl8192e/rtl819x_BAProc.c
@@ -428,7 +428,6 @@ int rtllib_rx_DELBA(struct rtllib_device *ieee, struct sk_buff *skb)
 {
 	 struct rtllib_hdr_3addr *delba = NULL;
 	union delba_param_set *pDelBaParamSet = NULL;
-	u16 *pReasonCode = NULL;
 	u8 *dst = NULL;
 
 	if (skb->len < sizeof(struct rtllib_hdr_3addr) + 6) {
@@ -453,9 +452,7 @@ int rtllib_rx_DELBA(struct rtllib_device *ieee, struct sk_buff *skb)
 #endif
 	delba = (struct rtllib_hdr_3addr *)skb->data;
 	dst = (u8 *)(&delba->addr2[0]);
-	delba += sizeof(struct rtllib_hdr_3addr);
-	pDelBaParamSet = (union delba_param_set *)(delba+2);
-	pReasonCode = (u16 *)(delba+4);
+	pDelBaParamSet = (union delba_param_set *)&delba->payload[2];
 
 	if (pDelBaParamSet->field.Initiator == 1) {
 		struct rx_ts_record *pRxTs;

Re: [patch 2/2 v2] Staging: rtl8192e: pointer math bug in rtllib_rx_DELBA()

[Mateusz Kulikowski]

On 19.07.2015 12:52, Dan Carpenter wrote:
> The pointer math here was totally wrong so we were reading nonsense
> information from beyond the end of the buffer.  It could lead to an oops
> if that memory wasn't mapped.
> 
> The "pReasonCode" pointer is assigned but never used so I deleted it.
> 
> With-Fix-From: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> v2: Mateusz noticed some more pointer math bugs on the next lines.
> 
> diff --git a/drivers/staging/rtl8192e/rtl819x_BAProc.c b/drivers/staging/rtl8192e/rtl819x_BAProc.c
> index 60f536c..78ede4a 100644
> --- a/drivers/staging/rtl8192e/rtl819x_BAProc.c
> +++ b/drivers/staging/rtl8192e/rtl819x_BAProc.c
> @@ -428,7 +428,6 @@ int rtllib_rx_DELBA(struct rtllib_device *ieee, struct sk_buff *skb)
>  {
>  	 struct rtllib_hdr_3addr *delba = NULL;
>  	union delba_param_set *pDelBaParamSet = NULL;
> -	u16 *pReasonCode = NULL;
>  	u8 *dst = NULL;
>  
>  	if (skb->len < sizeof(struct rtllib_hdr_3addr) + 6) {
> @@ -453,9 +452,7 @@ int rtllib_rx_DELBA(struct rtllib_device *ieee, struct sk_buff *skb)
>  #endif
>  	delba = (struct rtllib_hdr_3addr *)skb->data;
>  	dst = (u8 *)(&delba->addr2[0]);
> -	delba += sizeof(struct rtllib_hdr_3addr);
> -	pDelBaParamSet = (union delba_param_set *)(delba+2);
> -	pReasonCode = (u16 *)(delba+4);
> +	pDelBaParamSet = (union delba_param_set *)&delba->payload[2];
>  
>  	if (pDelBaParamSet->field.Initiator == 1) {
>  		struct rx_ts_record *pRxTs;
> 

Acked/Tested-by me 

Thanks,
Mateusz