Patch "mac80211: use constant time comparison with keys" has been added to the 4.4-stable tree

Patch "mac80211: use constant time comparison with keys" 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: use constant time comparison with keys

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-use-constant-time-comparison-with-keys.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 2bdd713b92a9cade239d3c7d15205a09f556624d Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Tue, 17 Oct 2017 20:32:07 +0200
Subject: mac80211: use constant time comparison with keys

From: Jason A. Donenfeld <Jason@zx2c4.com>

commit 2bdd713b92a9cade239d3c7d15205a09f556624d upstream.

Otherwise we risk leaking information via timing side channel.

Fixes: fdf7cb4185b6 ("mac80211: accept key reinstall without changing anything")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/mac80211/key.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -19,6 +19,7 @@
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <net/mac80211.h>
+#include <crypto/algapi.h>
 #include <asm/unaligned.h>
 #include "ieee80211_i.h"
 #include "driver-ops.h"
@@ -633,7 +634,7 @@ int ieee80211_key_link(struct ieee80211_
 	 * new version of the key to avoid nonce reuse or replay issues.
 	 */
 	if (old_key && key->conf.keylen == old_key->conf.keylen &&
-	    !memcmp(key->conf.key, old_key->conf.key, key->conf.keylen)) {
+	    !crypto_memneq(key->conf.key, old_key->conf.key, key->conf.keylen)) {
 		ieee80211_key_free_unused(key);
 		ret = 0;
 		goto out;


Patches currently in stable-queue which might be from Jason@zx2c4.com are

queue-4.4/mac80211-use-constant-time-comparison-with-keys.patch