[PATCH 4.6 002/203] mac80211: fix fast_tx header alignment

[Greg Kroah-Hartman]

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

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

From: Felix Fietkau <nbd@xxxxxxxx>

commit 6fe04128f158c5ad27e7504bfdf1b12e63331bc9 upstream.

The header field is defined as u8[] but also accessed as struct
ieee80211_hdr. Enforce an alignment of 2 to prevent unnecessary
unaligned accesses, which can be very harmful for performance on many
platforms.

Fixes: e495c24731a2 ("mac80211: extend fast-xmit for more ciphers")
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/mac80211/sta_info.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -275,7 +275,7 @@ struct ieee80211_fast_tx {
 	u8 sa_offs, da_offs, pn_offs;
 	u8 band;
 	u8 hdr[30 + 2 + IEEE80211_FAST_XMIT_MAX_IV +
-	       sizeof(rfc1042_header)];
+	       sizeof(rfc1042_header)] __aligned(2);
 
 	struct rcu_head rcu_head;
 };