linux-kernel - [PATCH 3.2 68/87] crypto: algif_skcipher

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <lsq.1454975631.571893534@decadent.org.uk>
Date:	Mon, 08 Feb 2016 23:53:51 +0000
From:	Ben Hutchings <ben@...adent.org.uk>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:	akpm@...ux-foundation.org, "Dmitry Vyukov" <dvyukov@...gle.com>,
	"Herbert Xu" <herbert@...dor.apana.org.au>
Subject: [PATCH 3.2 68/87] crypto: algif_skcipher - Require setkey before
 accept(2)

3.2.77-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Herbert Xu <herbert@...dor.apana.org.au>

commit dd504589577d8e8e70f51f997ad487a4cb6c026f upstream.

Some cipher implementations will crash if you try to use them
without calling setkey first.  This patch adds a check so that
the accept(2) call will fail with -ENOKEY if setkey hasn't been
done on the socket yet.

Reported-by: Dmitry Vyukov <dvyukov@...gle.com>
Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>
Tested-by: Dmitry Vyukov <dvyukov@...gle.com>
[bwh: Backported to 3.2: s/crypto_(alloc_|free_)?skcipher/crypto_\1ablkcipher/]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 crypto/algif_skcipher.c | 48 +++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 41 insertions(+), 7 deletions(-)

--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -31,6 +31,11 @@ struct skcipher_sg_list {
 	struct scatterlist sg[0];
 };
 
+struct skcipher_tfm {
+	struct crypto_ablkcipher *skcipher;
+	bool has_key;
+};
+
 struct skcipher_ctx {
 	struct list_head tsgl;
 	struct af_alg_sgl rsgl;
@@ -546,17 +551,41 @@ static struct proto_ops algif_skcipher_o
 
 static void *skcipher_bind(const char *name, u32 type, u32 mask)
 {
-	return crypto_alloc_ablkcipher(name, type, mask);
+	struct skcipher_tfm *tfm;
+	struct crypto_ablkcipher *skcipher;
+
+	tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
+	if (!tfm)
+		return ERR_PTR(-ENOMEM);
+
+	skcipher = crypto_alloc_ablkcipher(name, type, mask);
+	if (IS_ERR(skcipher)) {
+		kfree(tfm);
+		return ERR_CAST(skcipher);
+	}
+
+	tfm->skcipher = skcipher;
+
+	return tfm;
 }
 
 static void skcipher_release(void *private)
 {
-	crypto_free_ablkcipher(private);
+	struct skcipher_tfm *tfm = private;
+
+	crypto_free_ablkcipher(tfm->skcipher);
+	kfree(tfm);
 }
 
 static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
 {
-	return crypto_ablkcipher_setkey(private, key, keylen);
+	struct skcipher_tfm *tfm = private;
+	int err;
+
+	err = crypto_ablkcipher_setkey(tfm->skcipher, key, keylen);
+	tfm->has_key = !err;
+
+	return err;
 }
 
 static void skcipher_sock_destruct(struct sock *sk)
@@ -575,20 +604,25 @@ static int skcipher_accept_parent(void *
 {
 	struct skcipher_ctx *ctx;
 	struct alg_sock *ask = alg_sk(sk);
-	unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(private);
+	struct skcipher_tfm *tfm = private;
+	struct crypto_ablkcipher *skcipher = tfm->skcipher;
+	unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(skcipher);
+
+	if (!tfm->has_key)
+		return -ENOKEY;
 
 	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 	if (!ctx)
 		return -ENOMEM;
 
-	ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(private),
+	ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(skcipher),
 			       GFP_KERNEL);
 	if (!ctx->iv) {
 		sock_kfree_s(sk, ctx, len);
 		return -ENOMEM;
 	}
 
-	memset(ctx->iv, 0, crypto_ablkcipher_ivsize(private));
+	memset(ctx->iv, 0, crypto_ablkcipher_ivsize(skcipher));
 
 	INIT_LIST_HEAD(&ctx->tsgl);
 	ctx->len = len;
@@ -600,7 +634,7 @@ static int skcipher_accept_parent(void *
 
 	ask->private = ctx;
 
-	ablkcipher_request_set_tfm(&ctx->req, private);
+	ablkcipher_request_set_tfm(&ctx->req, skcipher);
 	ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 					af_alg_complete, &ctx->completion);