netfilter: nft_set_rbtree: allow loose matching of closing element in interval

Allow to find closest matching for the right side of an interval (end
flag set on) so we allow lookups in inner ranges, eg. 10-20 in 5-25.

Fixes: ba0e4d9917b4 ("netfilter: nf_tables: get set elements via netlink")
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index 0e5ec126f6ad0516acf0576f01c4430dec43aec8..fa61208371f8b222ceb43388773f5c19c691d764 100644 (file)
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -135,9 +135,12 @@ static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set,
                d = memcmp(this, key, set->klen);
                if (d < 0) {
                        parent = rcu_dereference_raw(parent->rb_left);
-                       interval = rbe;
+                       if (!(flags & NFT_SET_ELEM_INTERVAL_END))
+                               interval = rbe;
                } else if (d > 0) {
                        parent = rcu_dereference_raw(parent->rb_right);
+                       if (flags & NFT_SET_ELEM_INTERVAL_END)
+                               interval = rbe;
                } else {
                        if (!nft_set_elem_active(&rbe->ext, genmask))
                                parent = rcu_dereference_raw(parent->rb_left);
@@ -154,7 +157,10 @@ static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set,
 
        if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
            nft_set_elem_active(&interval->ext, genmask) &&
-           !nft_rbtree_interval_end(interval)) {
+           ((!nft_rbtree_interval_end(interval) &&
+             !(flags & NFT_SET_ELEM_INTERVAL_END)) ||
+            (nft_rbtree_interval_end(interval) &&
+             (flags & NFT_SET_ELEM_INTERVAL_END)))) {
                *elem = interval;
                return true;
        }