[PATCH 3.16 23/47] mwifiex: fix 802.11n/WPA detection

[Ben Hutchings]

3.16.76-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Brian Norris <briannorris@xxxxxxxxxxxx>

commit df612421fe2566654047769c6852ffae1a31df16 upstream.

Commit 63d7ef36103d ("mwifiex: Don't abort on small, spec-compliant
vendor IEs") adjusted the ieee_types_vendor_header struct, which
inadvertently messed up the offsets used in
mwifiex_is_wpa_oui_present(). Add that offset back in, mirroring
mwifiex_is_rsn_oui_present().

As it stands, commit 63d7ef36103d breaks compatibility with WPA (not
WPA2) 802.11n networks, since we hit the "info: Disable 11n if AES is
not supported by AP" case in mwifiex_is_network_compatible().

Fixes: 63d7ef36103d ("mwifiex: Don't abort on small, spec-compliant vendor IEs")
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/wireless/mwifiex/main.h | 1 +
 drivers/net/wireless/mwifiex/scan.c | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/mwifiex/main.h
+++ b/drivers/net/wireless/mwifiex/main.h
@@ -94,6 +94,7 @@ enum {
 
 #define MWIFIEX_MIN_TX_PENDING_TO_CANCEL_SCAN		2
 
+#define WPA_GTK_OUI_OFFSET				2
 #define RSN_GTK_OUI_OFFSET				2
 
 #define MWIFIEX_OUI_NOT_PRESENT			0
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -151,7 +151,8 @@ mwifiex_is_wpa_oui_present(struct mwifie
 	if (((bss_desc->bcn_wpa_ie) &&
 	     ((*(bss_desc->bcn_wpa_ie)).vend_hdr.element_id ==
 	      WLAN_EID_VENDOR_SPECIFIC))) {
-		iebody = (struct ie_body *) bss_desc->bcn_wpa_ie->data;
+		iebody = (struct ie_body *)((u8 *)bss_desc->bcn_wpa_ie->data +
+					    WPA_GTK_OUI_OFFSET);
 		oui = &mwifiex_wpa_oui[cipher][0];
 		ret = mwifiex_search_oui_in_ie(iebody, oui);
 		if (ret)