1 files changed, 40 insertions, 31 deletions

diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
index eeb7d31cbda5..4028e8eeba82 100644
--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	connector.c
  *
  * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
  * All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include <linux/compiler.h>
@@ -72,7 +59,8 @@ static int cn_already_initialized;
  * both, or if both are zero then the group is looked up and sent there.
  */
 int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 __group,
-	gfp_t gfp_mask)
+			 gfp_t gfp_mask, netlink_filter_fn filter,
+			 void *filter_data)
 {
 	struct cn_callback_entry *__cbq;
 	unsigned int size;
@@ -123,8 +111,9 @@ int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 __group,
 	NETLINK_CB(skb).dst_group = group;
 
 	if (group)
-		return netlink_broadcast(dev->nls, skb, portid, group,
-					 gfp_mask);
+		return netlink_broadcast_filtered(dev->nls, skb, portid, group,
+						  gfp_mask, filter,
+						  (void *)filter_data);
 	return netlink_unicast(dev->nls, skb, portid,
 			!gfpflags_allow_blocking(gfp_mask));
 }
@@ -134,7 +123,8 @@ EXPORT_SYMBOL_GPL(cn_netlink_send_mult);
 int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
 	gfp_t gfp_mask)
 {
-	return cn_netlink_send_mult(msg, msg->len, portid, __group, gfp_mask);
+	return cn_netlink_send_mult(msg, msg->len, portid, __group, gfp_mask,
+				    NULL, NULL);
 }
 EXPORT_SYMBOL_GPL(cn_netlink_send);
 
@@ -176,6 +166,31 @@ static int cn_call_callback(struct sk_buff *skb)
 }
 
 /*
+ * Allow non-root access for NETLINK_CONNECTOR family having CN_IDX_PROC
+ * multicast group.
+ */
+static int cn_bind(struct net *net, int group)
+{
+	unsigned long groups = (unsigned long) group;
+
+	if (ns_capable(net->user_ns, CAP_NET_ADMIN))
+		return 0;
+
+	if (test_bit(CN_IDX_PROC - 1, &groups))
+		return 0;
+
+	return -EPERM;
+}
+
+static void cn_release(struct sock *sk, unsigned long *groups)
+{
+	if (groups && test_bit(CN_IDX_PROC - 1, groups)) {
+		kfree(sk->sk_user_data);
+		sk->sk_user_data = NULL;
+	}
+}
+
+/*
  * Main netlink receiving function.
  *
  * It checks skb, netlink header and msg sizes, and calls callback helper.
@@ -206,21 +221,16 @@ static void cn_rx_skb(struct sk_buff *skb)
  *
  * May sleep.
  */
-int cn_add_callback(struct cb_id *id, const char *name,
+int cn_add_callback(const struct cb_id *id, const char *name,
 		    void (*callback)(struct cn_msg *,
 				     struct netlink_skb_parms *))
 {
-	int err;
 	struct cn_dev *dev = &cdev;
 
 	if (!cn_already_initialized)
 		return -EAGAIN;
 
-	err = cn_queue_add_callback(dev->cbdev, name, id, callback);
-	if (err)
-		return err;
-
-	return 0;
+	return cn_queue_add_callback(dev->cbdev, name, id, callback);
 }
 EXPORT_SYMBOL_GPL(cn_add_callback);
 
@@ -232,7 +242,7 @@ EXPORT_SYMBOL_GPL(cn_add_callback);
  *
  * May sleep while waiting for reference counter to become zero.
  */
-void cn_del_callback(struct cb_id *id)
+void cn_del_callback(const struct cb_id *id)
 {
 	struct cn_dev *dev = &cdev;
 
@@ -261,16 +271,15 @@ static int __maybe_unused cn_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static struct cn_dev cdev = {
-	.input   = cn_rx_skb,
-};
-
 static int cn_init(void)
 {
 	struct cn_dev *dev = &cdev;
 	struct netlink_kernel_cfg cfg = {
 		.groups	= CN_NETLINK_USERS + 0xf,
-		.input	= dev->input,
+		.input	= cn_rx_skb,
+		.flags  = NL_CFG_F_NONROOT_RECV,
+		.bind   = cn_bind,
+		.release = cn_release,
 	};
 
 	dev->nls = netlink_kernel_create(&init_net, NETLINK_CONNECTOR, &cfg);