This is a note to let you know that I've just added the patch titled
crypto: nx - Fix timing leak in GCM and CCM decryption
to the 4.3-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-nx-fix-timing-leak-in-gcm-and-ccm-decryption.patch
and it can be found in the queue-4.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cb8affb55c7e64816f3effcd9b2fc3268c016fac Mon Sep 17 00:00:00 2001
From: David Gstir <david@xxxxxxxxxxxxx>
Date: Sun, 15 Nov 2015 17:14:41 +0100
Subject: crypto: nx - Fix timing leak in GCM and CCM decryption
From: David Gstir <david@xxxxxxxxxxxxx>
commit cb8affb55c7e64816f3effcd9b2fc3268c016fac 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/nx/nx-aes-ccm.c | 2 +-
drivers/crypto/nx/nx-aes-gcm.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/crypto/nx/nx-aes-ccm.c
+++ b/drivers/crypto/nx/nx-aes-ccm.c
@@ -409,7 +409,7 @@ static int ccm_nx_decrypt(struct aead_re
processed += to_process;
} while (processed < nbytes);
- rc = memcmp(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag,
+ rc = crypto_memneq(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag,
authsize) ? -EBADMSG : 0;
out:
spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
--- a/drivers/crypto/nx/nx-aes-gcm.c
+++ b/drivers/crypto/nx/nx-aes-gcm.c
@@ -21,6 +21,7 @@
#include <crypto/internal/aead.h>
#include <crypto/aes.h>
+#include <crypto/algapi.h>
#include <crypto/scatterwalk.h>
#include <linux/module.h>
#include <linux/types.h>
@@ -418,7 +419,7 @@ mac:
itag, req->src, req->assoclen + nbytes,
crypto_aead_authsize(crypto_aead_reqtfm(req)),
SCATTERWALK_FROM_SG);
- rc = memcmp(itag, otag,
+ rc = crypto_memneq(itag, otag,
crypto_aead_authsize(crypto_aead_reqtfm(req))) ?
-EBADMSG : 0;
}
Patches currently in stable-queue which might be from david@xxxxxxxxxxxxx are
queue-4.3/crypto-nx-fix-timing-leak-in-gcm-and-ccm-decryption.patch
queue-4.3/crypto-talitos-fix-timing-leak-in-esp-icv-verification.patch
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