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From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, stable@vger.kernel.org
Subject: [PATCH 2/6] net/ipv6: use constant time memory comparison for mac
Date: Sat, 10 Jun 2017 04:59:08 +0200	[thread overview]
Message-ID: <20170610025912.6499-3-Jason@zx2c4.com> (raw)
In-Reply-To: <20170610025912.6499-1-Jason@zx2c4.com>

Otherwise, we enable a MAC forgery via timing attack.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
---
 net/ipv6/seg6_hmac.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c
index f950cb53d5e3..54213c83b44e 100644
--- a/net/ipv6/seg6_hmac.c
+++ b/net/ipv6/seg6_hmac.c
@@ -38,6 +38,7 @@
 #include <net/xfrm.h>
 
 #include <linux/cryptohash.h>
+#include <crypto/algapi.h>
 #include <crypto/hash.h>
 #include <crypto/sha.h>
 #include <net/seg6.h>
@@ -274,7 +275,7 @@ bool seg6_hmac_validate_skb(struct sk_buff *skb)
 	if (seg6_hmac_compute(hinfo, srh, &ipv6_hdr(skb)->saddr, hmac_output))
 		return false;
 
-	if (memcmp(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN) != 0)
+	if (crypto_memneq(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN))
 		return false;
 
 	return true;
-- 
2.13.1

  parent reply	other threads:[~2017-06-10  3:00 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-10  2:59 [PATCH 0/6] Constant Time Memory Comparisons Are Important Jason A. Donenfeld
2017-06-10  2:59 ` [PATCH 1/6] sunrpc: use constant time memory comparison for mac Jason A. Donenfeld
2017-06-10  2:59 ` Jason A. Donenfeld [this message]
2017-06-10  2:59 ` [PATCH 3/6] ccree: use constant time memory comparison for macs and tags Jason A. Donenfeld
2017-06-10  7:43   ` Gilad Ben-Yossef
2017-06-10 10:54     ` Jason A. Donenfeld
2017-06-10 21:43       ` Henrique de Moraes Holschuh
2017-06-10  2:59 ` [PATCH 4/6] security/keys: use constant time memory comparison for macs Jason A. Donenfeld
2017-06-14  8:47   ` [kernel-hardening] " James Morris
2017-06-10  2:59 ` [PATCH 5/6] bluetooth/smp: use constant time memory comparison for secret values Jason A. Donenfeld
2017-06-10 13:49   ` Marcel Holtmann
2017-06-10  2:59 ` [PATCH 6/6] mac80211/wpa: use constant time memory comparison for MACs Jason A. Donenfeld
2017-06-13  8:20   ` Johannes Berg
2017-06-13 13:28     ` Jason A. Donenfeld
2017-06-11  8:13 ` [PATCH 0/6] Constant Time Memory Comparisons Are Important Kalle Valo
2017-06-11 13:36   ` Kees Cook
2017-06-11 20:48     ` Emmanuel Grumbach
2017-06-11 21:30       ` Emil Lenngren
2017-06-12  5:03         ` Emmanuel Grumbach
2017-06-12  7:33         ` Arend van Spriel
2017-06-11 21:06 ` Stephan Müller
2017-06-11 21:21   ` Jason A. Donenfeld
2017-06-11 21:20 ` [PATCH] rsa-pkcs1pad: use constant time memory comparison for MACs Jason A. Donenfeld
2017-06-20  3:38   ` Herbert Xu

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