From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: David Gstir , Herbert Xu , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 078/305] crypto: nx - Fix timing leak in GCM and CCM decryption Date: Fri, 15 Jan 2016 15:58:12 -0800 Message-Id: <1452902519-2754-79-git-send-email-kamal@canonical.com> In-Reply-To: <1452902519-2754-1-git-send-email-kamal@canonical.com> References: <1452902519-2754-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: David Gstir 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 Signed-off-by: Herbert Xu Signed-off-by: Kamal Mostafa --- drivers/crypto/nx/nx-aes-ccm.c | 2 +- drivers/crypto/nx/nx-aes-gcm.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/crypto/nx/nx-aes-ccm.c b/drivers/crypto/nx/nx-aes-ccm.c index e4311ce..a1d0848 100644 --- a/drivers/crypto/nx/nx-aes-ccm.c +++ b/drivers/crypto/nx/nx-aes-ccm.c @@ -412,7 +412,7 @@ static int ccm_nx_decrypt(struct aead_request *req, 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); diff --git a/drivers/crypto/nx/nx-aes-gcm.c b/drivers/crypto/nx/nx-aes-gcm.c index 92c993f..1c478bc 100644 --- a/drivers/crypto/nx/nx-aes-gcm.c +++ b/drivers/crypto/nx/nx-aes-gcm.c @@ -414,7 +414,7 @@ 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; } -- 1.9.1