Patch "mac80211: fix fast_tx header alignment" has been added to the 4.4-stable tree

Patch "mac80211: fix fast_tx header alignment" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mac80211: fix fast_tx header alignment

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mac80211-fix-fast_tx-header-alignment.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 6fe04128f158c5ad27e7504bfdf1b12e63331bc9 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Thu, 19 May 2016 17:34:38 +0200
Subject: mac80211: fix fast_tx header alignment

From: Felix Fietkau <nbd@nbd.name>

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@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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
@@ -269,7 +269,7 @@ 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;
 };


Patches currently in stable-queue which might be from nbd@nbd.name are

queue-4.4/mac80211-fix-fast_tx-header-alignment.patch