[IPV4]: Possible leak of multicast source filter sctructure

There is a leak of a socket's multicast source filter list structure
on closing a socket with a multicast source filter set on an interface
that does not exist any more.

Signed-off-by: Michal Ruzicka <michal.ruzicka@comstar.cz>
Acked-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 9f4b752f5a337e7dfae09970d5112dc4bc6dc54b..e981369ebe13d2b10611ae3ec6134993bc08acc3 100644 (file)
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2199,13 +2199,13 @@ void ip_mc_drop_socket(struct sock *sk)
                struct in_device *in_dev;
                inet->mc_list = iml->next;
 
-               if ((in_dev = inetdev_by_index(iml->multi.imr_ifindex)) != NULL) {
-                       (void) ip_mc_leave_src(sk, iml, in_dev);
+               in_dev = inetdev_by_index(iml->multi.imr_ifindex);
+               (void) ip_mc_leave_src(sk, iml, in_dev);
+               if (in_dev != NULL) {
                        ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
                        in_dev_put(in_dev);
                }
                sock_kfree_s(sk, iml, sizeof(*iml));
-
        }
        rtnl_unlock();
 }