ipv4: fib: Send notification before deleting FIB alias

When a FIB alias is replaced following NLM_F_REPLACE, the ENTRY_ADD
notification is sent after the reference on the previous FIB info was
dropped. This is problematic as potential listeners might need to access
it in their notification blocks.

Solve this by sending the notification prior to the deletion of the
replaced FIB alias. This is consistent with ENTRY_DEL notifications.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index b0bfb1cc791aa3026241cadcdb1edfae97122650..1c4d42e46dbbdfb8b2403fd7fd673ae70dcd3be0 100644 (file)
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1295,6 +1295,13 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
                        new_fa->tb_id = tb->tb_id;
                        new_fa->fa_default = -1;
 
+                       call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_ADD,
+                                                key, plen, fi,
+                                                new_fa->fa_tos, cfg->fc_type,
+                                                tb->tb_id, nlflags);
+                       rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
+                                 tb->tb_id, &cfg->fc_nlinfo, nlflags);
+
                        hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
 
                        alias_free_mem_rcu(fa);
@@ -1303,13 +1310,6 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
                        if (state & FA_S_ACCESSED)
                                rt_cache_flush(cfg->fc_nlinfo.nl_net);
 
-                       call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_ADD,
-                                                key, plen, fi,
-                                                new_fa->fa_tos, cfg->fc_type,
-                                                tb->tb_id, cfg->fc_nlflags);
-                       rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
-                               tb->tb_id, &cfg->fc_nlinfo, nlflags);
-
                        goto succeeded;
                }
                /* Error if we find a perfect match which