From d9d7d7b99156c73be12c37a8d92aa0496a1b7f23 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Mon, 4 Sep 2023 02:14:36 +0200
Subject: [PATCH 1/3] netfilter: nft_set_rbtree: skip sync GC for new elements
in this transaction
Git-commit: 2ee52ae94baabf7ee09cf2a8d854b990dac5d0e4
Patch-mainline: v6.6-rc1
References: git-fixes CVE-2023-52433 bsc#1220137
New elements in this transaction might expired before such transaction
ends. Skip sync GC for such elements otherwise commit path might walk
over an already released object. Once transaction is finished, async GC
will collect such expired element.
Fixes: f6c383b8c31a ("netfilter: nf_tables: adapt set backend to use GC transaction API")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
net/netfilter/nft_set_rbtree.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index c6435e709231..f250b5399344 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -312,6 +312,7 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
struct nft_rbtree_elem *rbe, *rbe_le = NULL, *rbe_ge = NULL;
struct rb_node *node, *next, *parent, **p, *first = NULL;
struct nft_rbtree *priv = nft_set_priv(set);
+ u8 cur_genmask = nft_genmask_cur(net);
u8 genmask = nft_genmask_next(net);
int d, err;
@@ -357,8 +358,11 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
if (!nft_set_elem_active(&rbe->ext, genmask))
continue;
- /* perform garbage collection to avoid bogus overlap reports. */
- if (nft_set_elem_expired(&rbe->ext)) {
+ /* perform garbage collection to avoid bogus overlap reports
+ * but skip new elements in this transaction.
+ */
+ if (nft_set_elem_expired(&rbe->ext) &&
+ nft_set_elem_active(&rbe->ext, cur_genmask)) {
err = nft_rbtree_gc_elem(set, priv, rbe, genmask);
if (err < 0)
return err;
--
2.16.4