[3.16.y-ckt stable] Patch "crypto: af_alg - Add nokey compatibility path" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    crypto: af_alg - Add nokey compatibility path

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-ckt24.

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 9345e29743b6dfc28b995af7066fa84d967c0bf0 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert at gondor.apana.org.au>
Date: Mon, 4 Jan 2016 13:35:18 +0900
Subject: crypto: af_alg - Add nokey compatibility path

commit 37766586c965d63758ad542325a96d5384f4a8c9 upstream.

This patch adds a compatibility path to support old applications
that do acept(2) before setkey.

Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 crypto/af_alg.c         | 13 ++++++++++++-
 include/crypto/if_alg.h |  2 ++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 1971f3ccb09a..afe3dad23f08 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -76,6 +76,8 @@ int af_alg_register_type(const struct af_alg_type *type)
 		goto unlock;

 	type->ops->owner = THIS_MODULE;
+	if (type->ops_nokey)
+		type->ops_nokey->owner = THIS_MODULE;
 	node->type = type;
 	list_add(&node->list, &alg_types);
 	err = 0;
@@ -257,6 +259,7 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
 	const struct af_alg_type *type;
 	struct sock *sk2;
 	int err;
+	bool nokey;

 	lock_sock(sk);
 	type = ask->type;
@@ -275,12 +278,17 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
 	security_sk_clone(sk, sk2);

 	err = type->accept(ask->private, sk2);
+
+	nokey = err == -ENOKEY;
+	if (nokey && type->accept_nokey)
+		err = type->accept_nokey(ask->private, sk2);
+
 	if (err)
 		goto unlock;

 	sk2->sk_family = PF_ALG;

-	if (!ask->refcnt++)
+	if (nokey || !ask->refcnt++)
 		sock_hold(sk);
 	alg_sk(sk2)->parent = sk;
 	alg_sk(sk2)->type = type;
@@ -288,6 +296,9 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
 	newsock->ops = type->ops;
 	newsock->state = SS_CONNECTED;

+	if (nokey)
+		newsock->ops = type->ops_nokey;
+
 	err = 0;

 unlock:
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index 2f38daaab3d7..9e6a2f38c52f 100644
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -51,8 +51,10 @@ struct af_alg_type {
 	void (*release)(void *private);
 	int (*setkey)(void *private, const u8 *key, unsigned int keylen);
 	int (*accept)(void *private, struct sock *sk);
+	int (*accept_nokey)(void *private, struct sock *sk);

 	struct proto_ops *ops;
+	struct proto_ops *ops_nokey;
 	struct module *owner;
 	char name[14];
 };