1 files changed, 55 insertions, 21 deletions

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 8c7af02f8454..104732d34543 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -22,6 +22,8 @@
 #include <net/sock.h>
 #include <net/genetlink.h>
 
+#include "genetlink.h"
+
 static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
 static DECLARE_RWSEM(cb_lock);
 
@@ -995,7 +997,7 @@ static int genl_start(struct netlink_callback *cb)
 	info->info.attrs	= attrs;
 	genl_info_net_set(&info->info, sock_net(cb->skb->sk));
 	info->info.extack	= cb->extack;
-	memset(&info->info.user_ptr, 0, sizeof(info->info.user_ptr));
+	memset(&info->info.ctx, 0, sizeof(info->info.ctx));
 
 	cb->data = info;
 	if (ops->start) {
@@ -1102,7 +1104,7 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family,
 	info.attrs = attrbuf;
 	info.extack = extack;
 	genl_info_net_set(&info, net);
-	memset(&info.user_ptr, 0, sizeof(info.user_ptr));
+	memset(&info.ctx, 0, sizeof(info.ctx));
 
 	if (ops->pre_doit) {
 		err = ops->pre_doit(ops, skb, &info);
@@ -1232,7 +1234,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
 
 	hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
 	if (hdr == NULL)
-		return -1;
+		return -EMSGSIZE;
 
 	if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
 	    nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
@@ -1355,6 +1357,7 @@ static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
 	struct net *net = sock_net(skb->sk);
 	int fams_to_skip = cb->args[0];
 	unsigned int id;
+	int err = 0;
 
 	idr_for_each_entry(&genl_fam_idr, rt, id) {
 		if (!rt->netnsok && !net_eq(net, &init_net))
@@ -1363,16 +1366,17 @@ static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
 		if (n++ < fams_to_skip)
 			continue;
 
-		if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
-				   cb->nlh->nlmsg_seq, NLM_F_MULTI,
-				   skb, CTRL_CMD_NEWFAMILY) < 0) {
+		err = ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
+				     cb->nlh->nlmsg_seq, NLM_F_MULTI,
+				     skb, CTRL_CMD_NEWFAMILY);
+		if (err) {
 			n--;
 			break;
 		}
 	}
 
 	cb->args[0] = n;
-	return skb->len;
+	return err;
 }
 
 static struct sk_buff *ctrl_build_family_msg(const struct genl_family *family,
@@ -1497,15 +1501,11 @@ static int genl_ctrl_event(int event, const struct genl_family *family,
 	if (IS_ERR(msg))
 		return PTR_ERR(msg);
 
-	if (!family->netnsok) {
+	if (!family->netnsok)
 		genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
 					0, GFP_KERNEL);
-	} else {
-		rcu_read_lock();
-		genlmsg_multicast_allns(&genl_ctrl, msg, 0,
-					0, GFP_ATOMIC);
-		rcu_read_unlock();
-	}
+	else
+		genlmsg_multicast_allns(&genl_ctrl, msg, 0, 0);
 
 	return 0;
 }
@@ -1836,6 +1836,9 @@ static int genl_bind(struct net *net, int group)
 		    !ns_capable(net->user_ns, CAP_SYS_ADMIN))
 			ret = -EPERM;
 
+		if (family->bind)
+			family->bind(i);
+
 		break;
 	}
 
@@ -1843,12 +1846,39 @@ static int genl_bind(struct net *net, int group)
 	return ret;
 }
 
+static void genl_unbind(struct net *net, int group)
+{
+	const struct genl_family *family;
+	unsigned int id;
+
+	down_read(&cb_lock);
+
+	idr_for_each_entry(&genl_fam_idr, family, id) {
+		int i;
+
+		if (family->n_mcgrps == 0)
+			continue;
+
+		i = group - family->mcgrp_offset;
+		if (i < 0 || i >= family->n_mcgrps)
+			continue;
+
+		if (family->unbind)
+			family->unbind(i);
+
+		break;
+	}
+
+	up_read(&cb_lock);
+}
+
 static int __net_init genl_pernet_init(struct net *net)
 {
 	struct netlink_kernel_cfg cfg = {
 		.input		= genl_rcv,
 		.flags		= NL_CFG_F_NONROOT_RECV,
 		.bind		= genl_bind,
+		.unbind		= genl_unbind,
 		.release	= genl_release,
 	};
 
@@ -1895,23 +1925,23 @@ problem:
 
 core_initcall(genl_init);
 
-static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
-			 gfp_t flags)
+static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group)
 {
 	struct sk_buff *tmp;
 	struct net *net, *prev = NULL;
 	bool delivered = false;
 	int err;
 
+	rcu_read_lock();
 	for_each_net_rcu(net) {
 		if (prev) {
-			tmp = skb_clone(skb, flags);
+			tmp = skb_clone(skb, GFP_ATOMIC);
 			if (!tmp) {
 				err = -ENOMEM;
 				goto error;
 			}
 			err = nlmsg_multicast(prev->genl_sock, tmp,
-					      portid, group, flags);
+					      portid, group, GFP_ATOMIC);
 			if (!err)
 				delivered = true;
 			else if (err != -ESRCH)
@@ -1920,27 +1950,31 @@ static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
 
 		prev = net;
 	}
+	err = nlmsg_multicast(prev->genl_sock, skb, portid, group, GFP_ATOMIC);
+
+	rcu_read_unlock();
 
-	err = nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
 	if (!err)
 		delivered = true;
 	else if (err != -ESRCH)
 		return err;
 	return delivered ? 0 : -ESRCH;
  error:
+	rcu_read_unlock();
+
 	kfree_skb(skb);
 	return err;
 }
 
 int genlmsg_multicast_allns(const struct genl_family *family,
 			    struct sk_buff *skb, u32 portid,
-			    unsigned int group, gfp_t flags)
+			    unsigned int group)
 {
 	if (WARN_ON_ONCE(group >= family->n_mcgrps))
 		return -EINVAL;
 
 	group = family->mcgrp_offset + group;
-	return genlmsg_mcast(skb, portid, group, flags);
+	return genlmsg_mcast(skb, portid, group);
 }
 EXPORT_SYMBOL(genlmsg_multicast_allns);