[MCAST]: Fix filter leak on device removal.

This fixes source filter leakage when a device is removed and a
process leaves the group thereafter.

This also includes corresponding fixes for IPv6 multicast source
filters on device removal.
Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/igmp.c

@@ -1793,29 +1793,35 @@ int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
 	struct in_device *in_dev;
 	u32 group = imr->imr_multiaddr.s_addr;
 	u32 ifindex;
+	int ret = -EADDRNOTAVAIL;
 
 	rtnl_lock();
 	in_dev = ip_mc_find_dev(imr);
-	if (!in_dev) {
-		rtnl_unlock();
-		return -ENODEV;
-	}
 	ifindex = imr->imr_ifindex;
 	for (imlp = &inet->mc_list; (iml = *imlp) != NULL; imlp = &iml->next) {
-		if (iml->multi.imr_multiaddr.s_addr == group &&
-		    iml->multi.imr_ifindex == ifindex) {
-			(void) ip_mc_leave_src(sk, iml, in_dev);
+		if (iml->multi.imr_multiaddr.s_addr != group)
+			continue;
+		if (ifindex) {
+			if (iml->multi.imr_ifindex != ifindex)
+				continue;
+		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
+				iml->multi.imr_address.s_addr)
+			continue;
 
-			*imlp = iml->next;
+		(void) ip_mc_leave_src(sk, iml, in_dev);
 
+		*imlp = iml->next;
+
+		if (in_dev)
 			ip_mc_dec_group(in_dev, group);
-			rtnl_unlock();
-			sock_kfree_s(sk, iml, sizeof(*iml));
-			return 0;
-		}
+		rtnl_unlock();
+		sock_kfree_s(sk, iml, sizeof(*iml));
+		return 0;
 	}
+	if (!in_dev)
+		ret = -ENODEV;
 	rtnl_unlock();
-	return -EADDRNOTAVAIL;
+	return ret;
 }
 
 int ip_mc_source(int add, int omode, struct sock *sk, struct

net/ipv6/mcast.c

@@ -268,13 +268,14 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
 			if ((dev = dev_get_by_index(mc_lst->ifindex)) != NULL) {
 				struct inet6_dev *idev = in6_dev_get(dev);
 
+				(void) ip6_mc_leave_src(sk, mc_lst, idev);
 				if (idev) {
-					(void) ip6_mc_leave_src(sk,mc_lst,idev);
 					__ipv6_dev_mc_dec(idev, &mc_lst->addr);
 					in6_dev_put(idev);
 				}
 				dev_put(dev);
-			}
+			} else
+				(void) ip6_mc_leave_src(sk, mc_lst, NULL);
 			sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
 			return 0;
 		}
@@ -334,13 +335,14 @@ void ipv6_sock_mc_close(struct sock *sk)
 		if (dev) {
 			struct inet6_dev *idev = in6_dev_get(dev);
 
+			(void) ip6_mc_leave_src(sk, mc_lst, idev);
 			if (idev) {
-				(void) ip6_mc_leave_src(sk, mc_lst, idev);
 				__ipv6_dev_mc_dec(idev, &mc_lst->addr);
 				in6_dev_put(idev);
 			}
 			dev_put(dev);
-		}
+		} else
+			(void) ip6_mc_leave_src(sk, mc_lst, NULL);
 
 		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));