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From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Johannes Berg <johannes@sipsolutions.net>,
	David Miller <davem@davemloft.net>,
	netdev@vger.kernel.org, linux-wireless@vger.kernel.org
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Subject: [PATCH] mac80211: use constant time comparison with keys
Date: Tue, 17 Oct 2017 20:32:07 +0200	[thread overview]
Message-ID: <20171017183207.23124-1-Jason@zx2c4.com> (raw)
In-Reply-To: <CAHmME9qd_m-FDj1E+eiBYWKvnMBvr0tWVcJ4ph2tr=Y1d_tb1g@mail.gmail.com>

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

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index ae995c8480db..035d16fe926e 100644
--- 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"
@@ -635,7 +636,7 @@ int ieee80211_key_link(struct ieee80211_key *key,
 	 * 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;
-- 
2.14.2

WARNING: multiple messages have this Message-ID (diff)
From: "Jason A. Donenfeld" <Jason-OnJsPKxuuEcAvxtiuMwx3w@public.gmane.org>
To: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>,
	David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>,
	netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: "Jason A. Donenfeld" <Jason-OnJsPKxuuEcAvxtiuMwx3w@public.gmane.org>
Subject: [PATCH] mac80211: use constant time comparison with keys
Date: Tue, 17 Oct 2017 20:32:07 +0200	[thread overview]
Message-ID: <20171017183207.23124-1-Jason@zx2c4.com> (raw)
In-Reply-To: <CAHmME9qd_m-FDj1E+eiBYWKvnMBvr0tWVcJ4ph2tr=Y1d_tb1g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

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-OnJsPKxuuEcAvxtiuMwx3w@public.gmane.org>
---
 net/mac80211/key.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index ae995c8480db..035d16fe926e 100644
--- 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"
@@ -635,7 +636,7 @@ int ieee80211_key_link(struct ieee80211_key *key,
 	 * 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;
-- 
2.14.2

  reply	other threads:[~2017-10-17 18:32 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-16 13:46 pull-request: mac80211 2017-10-16 Johannes Berg
2017-10-16 13:46 ` Johannes Berg
2017-10-16 20:29 ` David Miller
2017-10-16 23:30 ` Jason A. Donenfeld
2017-10-17  5:46   ` Johannes Berg
2017-10-17  5:46     ` Johannes Berg
2017-10-17 18:21     ` Jason A. Donenfeld
2017-10-17 18:32       ` Jason A. Donenfeld [this message]
2017-10-17 18:32         ` [PATCH] mac80211: use constant time comparison with keys Jason A. Donenfeld
2017-10-18 10:17         ` Johannes Berg

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