[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>

1 files changed, 19 insertions, 13 deletions

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index e981369ebe13..8e8117c19e4d 100644
--- a/net/ipv4/igmp.c
+++ b/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