[PATCH 4.3 007/200] crypto: talitos - Fix timing leak in ESP ICV verification

[Greg Kroah-Hartman]

4.3-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Gstir <david@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/crypto/talitos.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -1015,7 +1015,7 @@ static void ipsec_esp_decrypt_swauth_don
 		} else
 			oicv = (char *)&edesc->link_tbl[0];
 
-		err = memcmp(oicv, icv, authsize) ? -EBADMSG : 0;
+		err = crypto_memneq(oicv, icv, authsize) ? -EBADMSG : 0;
 	}
 
 	kfree(edesc);