This is a note to let you know that I've just added the patch titled
sunrpc: use constant time memory comparison for mac
to the 4.12-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:
sunrpc-use-constant-time-memory-comparison-for-mac.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 15a8b93fd5690de017ce665382ea45e5d61811a4 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@xxxxxxxxx>
Date: Sat, 10 Jun 2017 04:59:07 +0200
Subject: sunrpc: use constant time memory comparison for mac
From: Jason A. Donenfeld <Jason@xxxxxxxxx>
commit 15a8b93fd5690de017ce665382ea45e5d61811a4 upstream.
Otherwise, we enable a MAC forgery via timing attack.
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
Cc: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: Anna Schumaker <anna.schumaker@xxxxxxxxxx>
Cc: linux-nfs@xxxxxxxxxxxxxxx
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sunrpc/auth_gss/gss_krb5_crypto.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -34,6 +34,7 @@
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
+#include <crypto/algapi.h>
#include <crypto/hash.h>
#include <crypto/skcipher.h>
#include <linux/err.h>
@@ -927,7 +928,7 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kc
if (ret)
goto out_err;
- if (memcmp(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
+ if (crypto_memneq(pkt_hmac, our_hmac, kctx->gk5e->cksumlength) != 0) {
ret = GSS_S_BAD_SIG;
goto out_err;
}
Patches currently in stable-queue which might be from Jason@xxxxxxxxx are
queue-4.12/sunrpc-use-constant-time-memory-comparison-for-mac.patch
queue-4.12/bluetooth-use-constant-time-memory-comparison-for-secret-values.patch