From: David Gstir <david@sigma-star.at>
Date: Sun, 15 Nov 2015 16:14:42 +0000 (+0100)
Subject: crypto: talitos - Fix timing leak in ESP ICV verification
X-Git-Tag: v4.3.6~195
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1f8b52002e010be989eb2e02bd0c90b65bdb3683;p=thirdparty%2Fkernel%2Fstable.git

crypto: talitos - Fix timing leak in ESP ICV verification

commit 79960943fdc114fd4583c9ab164b5c89da7aa601 upstream.

Using non-constant time memcmp() makes the verification of the authentication
tag in the decrypt path vulnerable to timing attacks. Fix this by using
crypto_memneq() instead.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index 3b20a1bce703f..8b327d89a8fc9 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -1015,7 +1015,7 @@ static void ipsec_esp_decrypt_swauth_done(struct device *dev,
 		} else
 			oicv = (char *)&edesc->link_tbl[0];
 
-		err = memcmp(oicv, icv, authsize) ? -EBADMSG : 0;
+		err = crypto_memneq(oicv, icv, authsize) ? -EBADMSG : 0;
 	}
 
 	kfree(edesc);