1 files changed, 39 insertions, 10 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 3ae3cb81656..a007dbb4c9f 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -85,6 +85,7 @@ struct netlink_sock {
 
 #define NETLINK_KERNEL_SOCKET	0x1
 #define NETLINK_RECV_PKTINFO	0x2
+#define NETLINK_BROADCAST_SEND_ERROR	0x4
 
 static inline struct netlink_sock *nlk_sk(struct sock *sk)
 {
@@ -950,6 +951,7 @@ struct netlink_broadcast_data {
 	u32 pid;
 	u32 group;
 	int failure;
+	int delivery_failure;
 	int congested;
 	int delivered;
 	gfp_t allocation;
@@ -994,11 +996,15 @@ static inline int do_one_broadcast(struct sock *sk,
 		netlink_overrun(sk);
 		/* Clone failed. Notify ALL listeners. */
 		p->failure = 1;
+		if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
+			p->delivery_failure = 1;
 	} else if (sk_filter(sk, p->skb2)) {
 		kfree_skb(p->skb2);
 		p->skb2 = NULL;
 	} else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
 		netlink_overrun(sk);
+		if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
+			p->delivery_failure = 1;
 	} else {
 		p->congested |= val;
 		p->delivered = 1;
@@ -1025,6 +1031,7 @@ int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
 	info.pid = pid;
 	info.group = group;
 	info.failure = 0;
+	info.delivery_failure = 0;
 	info.congested = 0;
 	info.delivered = 0;
 	info.allocation = allocation;
@@ -1042,16 +1049,16 @@ int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
 
 	netlink_unlock_table();
 
-	if (info.skb2)
-		kfree_skb(info.skb2);
+	kfree_skb(info.skb2);
+
+	if (info.delivery_failure)
+		return -ENOBUFS;
 
 	if (info.delivered) {
 		if (info.congested && (allocation & __GFP_WAIT))
 			yield();
 		return 0;
 	}
-	if (info.failure)
-		return -ENOBUFS;
 	return -ESRCH;
 }
 EXPORT_SYMBOL(netlink_broadcast);
@@ -1167,6 +1174,13 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
 		err = 0;
 		break;
 	}
+	case NETLINK_BROADCAST_ERROR:
+		if (val)
+			nlk->flags |= NETLINK_BROADCAST_SEND_ERROR;
+		else
+			nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
+		err = 0;
+		break;
 	default:
 		err = -ENOPROTOOPT;
 	}
@@ -1199,6 +1213,16 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
 			return -EFAULT;
 		err = 0;
 		break;
+	case NETLINK_BROADCAST_ERROR:
+		if (len < sizeof(int))
+			return -EINVAL;
+		len = sizeof(int);
+		val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0;
+		if (put_user(len, optlen) ||
+		    put_user(val, optval))
+			return -EFAULT;
+		err = 0;
+		break;
 	default:
 		err = -ENOPROTOOPT;
 	}
@@ -1525,8 +1549,7 @@ EXPORT_SYMBOL(netlink_set_nonroot);
 
 static void netlink_destroy_callback(struct netlink_callback *cb)
 {
-	if (cb->skb)
-		kfree_skb(cb->skb);
+	kfree_skb(cb->skb);
 	kfree(cb);
 }
 
@@ -1743,12 +1766,18 @@ int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
 			exclude_pid = pid;
 		}
 
-		/* errors reported via destination sk->sk_err */
-		nlmsg_multicast(sk, skb, exclude_pid, group, flags);
+		/* errors reported via destination sk->sk_err, but propagate
+		 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
+		err = nlmsg_multicast(sk, skb, exclude_pid, group, flags);
 	}
 
-	if (report)
-		err = nlmsg_unicast(sk, skb, pid);
+	if (report) {
+		int err2;
+
+		err2 = nlmsg_unicast(sk, skb, pid);
+		if (!err || err == -ESRCH)
+			err = err2;
+	}
 
 	return err;
 }