[PATCH 5.6 110/194] netfilter: nft_set_rbtree: Add missing expired checks

Greg Kroah-Hartman
2020-05-18T18:11:48Z

From: Phil Sutter <phil@nwl.cc>

[ Upstream commit 340eaff651160234bdbce07ef34b92a8e45cd540 ]

Expired intervals would still match and be dumped to user space until
garbage collection wiped them out. Make sure they stop matching and
disappear (from users' perspective) as soon as they expire.

Fixes: 8d8540c4f5e03 ("netfilter: nft_set_rbtree: add timeout support")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nft_set_rbtree.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index 46d976969ca30..accbb54c2b714 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -79,6 +79,10 @@ static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set
parent = rcu_dereference_raw(parent->rb_left);
continue;
}
+
+ if (nft_set_elem_expired(&rbe->ext))
+ return false;
+
if (nft_rbtree_interval_end(rbe)) {
if (nft_set_is_anonymous(set))
return false;
@@ -94,6 +98,7 @@ static bool __nft_rbtree_lookup(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_set_elem_expired(&interval->ext) &&
nft_rbtree_interval_start(interval)) {
*ext = &interval->ext;
return true;
@@ -154,6 +159,9 @@ static bool __nft_rbtree_get(const struct net *net, const struct nft_set *set,
continue;
}

+ if (nft_set_elem_expired(&rbe->ext))
+ return false;
+
if (!nft_set_ext_exists(&rbe->ext, NFT_SET_EXT_FLAGS) ||
(*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END) ==
(flags & NFT_SET_ELEM_INTERVAL_END)) {
@@ -170,6 +178,7 @@ 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_set_elem_expired(&interval->ext) &&
((!nft_rbtree_interval_end(interval) &&
!(flags & NFT_SET_ELEM_INTERVAL_END)) ||
(nft_rbtree_interval_end(interval) &&
@@ -418,6 +427,8 @@ static void nft_rbtree_walk(const struct nft_ctx *ctx,

if (iter->count < iter->skip)
goto cont;
+ if (nft_set_elem_expired(&rbe->ext))
+ goto cont;
if (!nft_set_elem_active(&rbe->ext, iter->genmask))
goto cont;

--
2.20.1