bridge: Fix return values of br_multicast_add_group/br_multicast_new_group

If br_multicast_new_group returns NULL, we would return 0 (no error) to
the caller of br_multicast_add_group, which is not what we want. Instead
br_multicast_new_group should return ERR_PTR(-ENOMEM) in this case.
Also propagate the error number returned by br_mdb_rehash properly.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 4 deletions

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 326e599f83fb..85a0398b221e 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -654,11 +654,13 @@ static struct net_bridge_mdb_entry *br_multicast_new_group(
         struct net_bridge_mdb_htable *mdb;
         struct net_bridge_mdb_entry *mp;
         int hash;
+        int err;
 
         mdb = rcu_dereference_protected(br->mdb, 1);
         if (!mdb) {
-                if (br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0))
-                        return NULL;
+                err = br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0);
+                if (err)
+                        return ERR_PTR(err);
                 goto rehash;
         }
 
@@ -680,7 +682,7 @@ rehash:
 
         mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
         if (unlikely(!mp))
-                goto out;
+                return ERR_PTR(-ENOMEM);
 
         mp->br = br;
         mp->addr = *group;
@@ -713,7 +715,7 @@ static int br_multicast_add_group(struct net_bridge *br,
 
         mp = br_multicast_new_group(br, port, group);
         err = PTR_ERR(mp);
-        if (unlikely(IS_ERR(mp) || !mp))
+        if (IS_ERR(mp))
                 goto err;
 
         if (!port) {