[PATCH 3.8 50/91] rtlwifi: rtl8192cu: Fix error in pointer arithmetic

[Kamal Mostafa]

3.8.13.13 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mark Cave-Ayland <mark.cave-ayland at ilande.co.uk>

commit 9473ca6e920a3b9ca902753ce52833657f9221cc upstream.

An error in calculating the offset in an skb causes the driver to read
essential device info from the wrong locations. The main effect is that
automatic gain calculations are nonsense.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland at ilande.co.uk>
Signed-off-by: Larry Finger <Larry.Finger at lwfinger.net>
Signed-off-by: John W. Linville <linville at tuxdriver.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/wireless/rtlwifi/rtl8192cu/trx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/rtlwifi/rtl8192cu/trx.c b/drivers/net/wireless/rtlwifi/rtl8192cu/trx.c
index b6222ee..03b6d81 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192cu/trx.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192cu/trx.c
@@ -343,7 +343,8 @@ bool rtl92cu_rx_query_desc(struct ieee80211_hw *hw,
 					(bool)GET_RX_DESC_PAGGR(pdesc));
 	rx_status->mactime = GET_RX_DESC_TSFL(pdesc);
 	if (phystatus) {
-		p_drvinfo = (struct rx_fwinfo_92c *)(pdesc + RTL_RX_DESC_SIZE);
+		p_drvinfo = (struct rx_fwinfo_92c *)(skb->data +
+						     stats->rx_bufshift);
 		rtl92c_translate_rx_signal_stuff(hw, skb, stats, pdesc,
 						 p_drvinfo);
 	}
-- 
1.8.1.2