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[3.16.y-ckt,stable] Patch "crypto: algif_skcipher - Require setkey before accept(2)" has been added to the 3.16.y-ckt tree

Message ID 1456425136-15324-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Feb. 25, 2016, 6:32 p.m. UTC
This is a note to let you know that I have just added a patch titled

    crypto: algif_skcipher - Require setkey before accept(2)

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt25.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

From 21a017c3cb97b376833e1b70898ef3f95bc9fc2a Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Fri, 25 Dec 2015 15:40:05 +0800
Subject: crypto: algif_skcipher - Require setkey before accept(2)

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

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index bb68c92e68c6..10c1fd04f1ed 100644
--- 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_ops = {

 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 *private, struct sock *sk)
 {
 	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 *private, struct sock *sk)

 	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);