[PATCH 3/4] crypto: gcm wait for crypto op not signal safe

Path	csiph.com!news.freedyn.net!open-news-network.org!aioe.org!bofh.it!news.nic.it!robomod
From	Gilad Ben-Yossef <gilad@benyossef.com>
Newsgroups	linux.kernel
Subject	[PATCH 3/4] crypto: gcm wait for crypto op not signal safe
Date	Thu, 11 May 2017 14:00:02 +0200
Message-ID	<tFUVc-5Qu-5@gated-at.bofh.it> (permalink)
References	<tFUVb-5Qu-3@gated-at.bofh.it>
X-Mailer	git-send-email 2.1.4
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	49
Organization	linux.* mail to news gateway
X-Original-Cc	Ofir Drang <ofir.drang@arm.com>, Gilad Ben-Yossef <gilad.benyossef@arm.com>, Eric Biggers <ebiggers3@gmail.com>, stable@vger.kernel.org, linux-crypto@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, keyrings@vger.kernel.org
X-Original-Date	Thu, 11 May 2017 14:53:44 +0300
X-Original-Message-ID	<1494503626-15877-4-git-send-email-gilad@benyossef.com>
X-Original-References	<1494503626-15877-1-git-send-email-gilad@benyossef.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1639330

Show key headers only | View raw

crypto_gcm_setkey() was using wait_for_completion_interruptible() to
wait for completion of async crypto op but if a signal occurs it
may return before DMA ops of HW crypto provider finish, thus
corrupting the data buffer that is kfree'ed in this case.

Resolve this by using wait_for_completion() instead.

Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
CC: stable@vger.kernel.org
---
 crypto/drbg.c | 4 ++--
 crypto/gcm.c  | 6 ++----
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/crypto/drbg.c b/crypto/drbg.c
index fa9054d..cdb27ac 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1767,8 +1767,8 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
 			break;
 		case -EINPROGRESS:
 		case -EBUSY:
-			ret = wait_for_completion(&drbg->ctr_completion);
-			if (!ret && !drbg->ctr_async_err) {
+			wait_for_completion(&drbg->ctr_completion);
+			if (!drbg->ctr_async_err) {
 				reinit_completion(&drbg->ctr_completion);
 				break;
 			}
diff --git a/crypto/gcm.c b/crypto/gcm.c
index b7ad808..3841b5e 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -152,10 +152,8 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 
 	err = crypto_skcipher_encrypt(&data->req);
 	if (err == -EINPROGRESS || err == -EBUSY) {
-		err = wait_for_completion_interruptible(
-			&data->result.completion);
-		if (!err)
-			err = data->result.err;
+		wait_for_completion(&data->result.completion);
+		err = data->result.err;
 	}
 
 	if (err)
-- 
2.1.4

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH 3/4] crypto: gcm wait for crypto op not signal safe Gilad Ben-Yossef <gilad@benyossef.com> - 2017-05-11 14:00 +0200

csiph-web