Patch "crypto: rsa-pkcs1pad - use constant time memory comparison for MACs" has been added to the 4.9-stable tree

Patch "crypto: rsa-pkcs1pad - use constant time memory comparison for MACs" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    crypto: rsa-pkcs1pad - use constant time memory comparison for MACs

to the 4.9-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:
     crypto-rsa-pkcs1pad-use-constant-time-memory-comparison-for-macs.patch
and it can be found in the queue-4.9 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 fec17cb2231733174e039ad9054fa16bb358e2ec Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sun, 11 Jun 2017 23:20:23 +0200
Subject: crypto: rsa-pkcs1pad - use constant time memory comparison for MACs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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

commit fec17cb2231733174e039ad9054fa16bb358e2ec upstream.

Otherwise, we enable all sorts of forgeries via timing attack.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Suggested-by: Stephan Müller <smueller@chronox.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 crypto/rsa-pkcs1pad.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -496,7 +496,7 @@ static int pkcs1pad_verify_complete(stru
 		goto done;
 	pos++;
 
-	if (memcmp(out_buf + pos, digest_info->data, digest_info->size))
+	if (crypto_memneq(out_buf + pos, digest_info->data, digest_info->size))
 		goto done;
 
 	pos += digest_info->size;


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

queue-4.9/crypto-rsa-pkcs1pad-use-constant-time-memory-comparison-for-macs.patch