[PATCH 3.10 18/74] rtlwifi: rtl8192cu: Fix error in pointer arithmetic

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Mark Cave-Ayland <mark.cave-ayland@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@ilande.co.uk>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/wireless/rtlwifi/rtl8192cu/trx.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- 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 ieee80
 					(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);
 	}