Merge branch 'sctp-process-the-error-returned-from-sctp_sock_migrate'

Xin Long says:

====================
sctp: process the error returned from sctp_sock_migrate()

This patchset is to process the errs returned by sctp_auth_init_hmacs()
and sctp_bind_addr_dup() from sctp_sock_migrate(). And also fix a panic
caused by new ep->auth_hmacs was not set due to net->sctp.auth_enable
changed by sysctl before accepting an assoc.
====================
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/auth.c

@@ -471,12 +471,6 @@ int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp)
 	struct crypto_shash *tfm = NULL;
 	__u16   id;
 
-	/* If AUTH extension is disabled, we are done */
-	if (!ep->auth_enable) {
-		ep->auth_hmacs = NULL;
-		return 0;
-	}
-
 	/* If the transforms are already allocated, we are done */
 	if (ep->auth_hmacs)
 		return 0;

net/sctp/endpointola.c

@@ -107,6 +107,13 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 			auth_chunks->param_hdr.length =
 					htons(sizeof(struct sctp_paramhdr) + 2);
 		}
+
+		/* Allocate and initialize transorms arrays for supported
+		 * HMACs.
+		 */
+		err = sctp_auth_init_hmacs(ep, gfp);
+		if (err)
+			goto nomem;
 	}
 
 	/* Initialize the base structure. */
@@ -150,15 +157,10 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 	INIT_LIST_HEAD(&ep->endpoint_shared_keys);
 	null_key = sctp_auth_shkey_create(0, gfp);
 	if (!null_key)
-		goto nomem;
+		goto nomem_shkey;
 
 	list_add(&null_key->key_list, &ep->endpoint_shared_keys);
 
-	/* Allocate and initialize transorms arrays for supported HMACs. */
-	err = sctp_auth_init_hmacs(ep, gfp);
-	if (err)
-		goto nomem_hmacs;
-
 	/* Add the null key to the endpoint shared keys list and
 	 * set the hmcas and chunks pointers.
 	 */
@@ -169,8 +171,8 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 
 	return ep;
 
-nomem_hmacs:
-	sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
+nomem_shkey:
+	sctp_auth_destroy_hmacs(ep->auth_hmacs);
 nomem:
 	/* Free all allocations */
 	kfree(auth_hmacs);

net/sctp/socket.c

@@ -102,9 +102,9 @@ static int sctp_send_asconf(struct sctp_association *asoc,
 			    struct sctp_chunk *chunk);
 static int sctp_do_bind(struct sock *, union sctp_addr *, int);
 static int sctp_autobind(struct sock *sk);
-static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
-			      struct sctp_association *assoc,
-			      enum sctp_socket_type type);
+static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
+			     struct sctp_association *assoc,
+			     enum sctp_socket_type type);
 
 static unsigned long sctp_memory_pressure;
 static atomic_long_t sctp_memory_allocated;
@@ -4891,7 +4891,11 @@ static struct sock *sctp_accept(struct sock *sk, int flags, int *err, bool kern)
 	/* Populate the fields of the newsk from the oldsk and migrate the
 	 * asoc to the newsk.
 	 */
-	sctp_sock_migrate(sk, newsk, asoc, SCTP_SOCKET_TCP);
+	error = sctp_sock_migrate(sk, newsk, asoc, SCTP_SOCKET_TCP);
+	if (error) {
+		sk_common_release(newsk);
+		newsk = NULL;
+	}
 
 out:
 	release_sock(sk);
@@ -5639,7 +5643,12 @@ int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp)
 	/* Populate the fields of the newsk from the oldsk and migrate the
 	 * asoc to the newsk.
 	 */
-	sctp_sock_migrate(sk, sock->sk, asoc, SCTP_SOCKET_UDP_HIGH_BANDWIDTH);
+	err = sctp_sock_migrate(sk, sock->sk, asoc,
+				SCTP_SOCKET_UDP_HIGH_BANDWIDTH);
+	if (err) {
+		sock_release(sock);
+		sock = NULL;
+	}
 
 	*sockp = sock;
 
@@ -9171,9 +9180,9 @@ static inline void sctp_copy_descendant(struct sock *sk_to,
 /* Populate the fields of the newsk from the oldsk and migrate the assoc
  * and its messages to the newsk.
  */
-static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
-			      struct sctp_association *assoc,
-			      enum sctp_socket_type type)
+static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
+			     struct sctp_association *assoc,
+			     enum sctp_socket_type type)
 {
 	struct sctp_sock *oldsp = sctp_sk(oldsk);
 	struct sctp_sock *newsp = sctp_sk(newsk);
@@ -9182,6 +9191,7 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
 	struct sk_buff *skb, *tmp;
 	struct sctp_ulpevent *event;
 	struct sctp_bind_hashbucket *head;
+	int err;
 
 	/* Migrate socket buffer sizes and all the socket level options to the
 	 * new socket.
@@ -9210,8 +9220,20 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
 	/* Copy the bind_addr list from the original endpoint to the new
 	 * endpoint so that we can handle restarts properly
 	 */
-	sctp_bind_addr_dup(&newsp->ep->base.bind_addr,
-				&oldsp->ep->base.bind_addr, GFP_KERNEL);
+	err = sctp_bind_addr_dup(&newsp->ep->base.bind_addr,
+				 &oldsp->ep->base.bind_addr, GFP_KERNEL);
+	if (err)
+		return err;
+
+	/* New ep's auth_hmacs should be set if old ep's is set, in case
+	 * that net->sctp.auth_enable has been changed to 0 by users and
+	 * new ep's auth_hmacs couldn't be set in sctp_endpoint_init().
+	 */
+	if (oldsp->ep->auth_hmacs) {
+		err = sctp_auth_init_hmacs(newsp->ep, GFP_KERNEL);
+		if (err)
+			return err;
+	}
 
 	/* Move any messages in the old socket's receive queue that are for the
 	 * peeled off association to the new socket's receive queue.
@@ -9296,6 +9318,8 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
 	}
 
 	release_sock(newsk);
+
+	return 0;
 }