Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Kees Cook <keescook@chromium.org>
To:     Herbert Xu <herbert@gondor.apana.org.au>
Cc:     Kees Cook <keescook@chromium.org>, Arnd Bergmann <arnd@arndb.de>,
        Eric Biggers <ebiggers@google.com>,
        "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
        Alasdair Kergon <agk@redhat.com>,
        Rabin Vincent <rabinv@axis.com>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Pavel Machek <pavel@ucw.cz>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        Philipp Reisner <philipp.reisner@linbit.com>,
        Lars Ellenberg <lars.ellenberg@linbit.com>,
        Jens Axboe <axboe@kernel.dk>,
        Giovanni Cabiddu <giovanni.cabiddu@intel.com>,
        Mike Snitzer <snitzer@redhat.com>,
        Paul Mackerras <paulus@samba.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        David Howells <dhowells@redhat.com>,
        Johannes Berg <johannes@sipsolutions.net>,
        Tudor-Dan Ambarus <tudor.ambarus@microchip.com>,
        Jia-Ju Bai <baijiaju1990@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Will Deacon <will.deacon@arm.com>, dm-devel@redhat.com,
        linux-pm@vger.kernel.org, linux-crypto@vger.kernel.org,
        drbd-dev@lists.linbit.com, linux-block@vger.kernel.org,
        qat-linux@intel.com, linux-ppp@vger.kernel.org,
        netdev@vger.kernel.org, devel@driverdev.osuosl.org,
        linux-afs@lists.infradead.org, linux-wireless@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v6 06/18] crypto: qat: Remove VLA usage
Date:   Tue, 24 Jul 2018 09:49:24 -0700
Message-Id: <20180724164936.37477-7-keescook@chromium.org>
In-Reply-To: <20180724164936.37477-1-keescook@chromium.org>
References: <20180724164936.37477-1-keescook@chromium.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In the quest to remove all stack VLA usage from the kernel[1], this uses
the new upper bound for the stack buffer. Also adds a sanity check.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/crypto/qat/qat_common/qat_algs.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/qat/qat_common/qat_algs.c b/drivers/crypto/qat/qat_common/qat_algs.c
index 1138e41d6805..a28edf7b792f 100644
--- a/drivers/crypto/qat/qat_common/qat_algs.c
+++ b/drivers/crypto/qat/qat_common/qat_algs.c
@@ -153,8 +153,8 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 	struct sha512_state sha512;
 	int block_size = crypto_shash_blocksize(ctx->hash_tfm);
 	int digest_size = crypto_shash_digestsize(ctx->hash_tfm);
-	char ipad[block_size];
-	char opad[block_size];
+	char ipad[MAX_ALGAPI_BLOCKSIZE];
+	char opad[MAX_ALGAPI_BLOCKSIZE];
 	__be32 *hash_state_out;
 	__be64 *hash512_state_out;
 	int i, offset;
@@ -164,6 +164,10 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash,
 	shash->tfm = ctx->hash_tfm;
 	shash->flags = 0x0;
 
+	if (WARN_ON(block_size > sizeof(ipad) ||
+		    sizeof(ipad) != sizeof(opad)))
+		return -EINVAL;
+
 	if (auth_keylen > block_size) {
 		int ret = crypto_shash_digest(shash, auth_key,
 					      auth_keylen, ipad);
-- 
2.17.1