ipv4: fib: Only flush FIB aliases belonging to currently flushed table

In case the MAIN table is flushed and its trie is shared with the LOCAL
table, then we might be flushing FIB aliases belonging to the latter.
This can lead to FIB_ENTRY_DEL notifications sent with the wrong table
ID.

The above doesn't affect current listeners, as the table ID is ignored
during entry deletion, but this will change later in the patchset.

When flushing a particular table, skip any aliases belonging to a
different one.

Signed-off-by: Ido Schimmel <[email protected]>
Signed-off-by: Jiri Pirko <[email protected]>
CC: Alexander Duyck <[email protected]>
CC: Patrick McHardy <[email protected]>
Reviewed-by: Alexander Duyck <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: idosch

net/ipv4/fib_trie.c

@@ -1963,7 +1963,8 @@ int fib_table_flush(struct net *net, struct fib_table *tb)
 		hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
 			struct fib_info *fi = fa->fa_info;
 
-			if (!fi || !(fi->fib_flags & RTNH_F_DEAD)) {
+			if (!fi || !(fi->fib_flags & RTNH_F_DEAD) ||
+			    tb->tb_id != fa->tb_id) {
 				slen = fa->fa_slen;
 				continue;
 			}