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[v2,1/1] netfilter: nf_tables: remove catchall element in GC sync path

Message ID 20231120204045.69637-2-yuxuan.luo@canonical.com
State New
Headers show
Series CVE-2023-6111 | expand

Commit Message

Yuxuan Luo Nov. 20, 2023, 8:40 p.m. UTC 
From: Pablo Neira Ayuso <pablo@netfilter.org>

The expired catchall element is not deactivated and removed from GC sync
path. This path holds mutex so just call nft_setelem_data_deactivate()
and nft_setelem_catchall_remove() before queueing the GC work.

Fixes: 4a9e12ea7e70 ("netfilter: nft_set_pipapo: call nft_trans_gc_queue_sync() in catchall GC")
Reported-by: lonial con <kongln9170@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
(backported from commit 93995bf4af2c5a99e2a87f0cd5ce547d31eb7630)
[yuxuan.luo: the prerequisite commit 0e1ea651c971 ("netfilter:
 nf_tables: shrink memory consumption of set elements") can be ignored
 by keeping nft_set_elem struct type and substitute nft_elem_priv
 variables with old elem->priv.
]
CVE-2023-6111
Signed-off-by: Yuxuan Luo <yuxuan.luo@canonical.com>
---
 net/netfilter/nf_tables_api.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 4760caf59e3f5..e6e9dfeef4933 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6198,6 +6198,12 @@  static int nft_setelem_deactivate(const struct net *net,
 	return ret;
 }
 
+static void nft_setelem_catchall_destroy(struct nft_set_elem_catchall *catchall)
+{
+	list_del_rcu(&catchall->list);
+	kfree_rcu(catchall, rcu);
+}
+
 static void nft_setelem_catchall_remove(const struct net *net,
 					const struct nft_set *set,
 					const struct nft_set_elem *elem)
@@ -6206,8 +6212,7 @@  static void nft_setelem_catchall_remove(const struct net *net,
 
 	list_for_each_entry_safe(catchall, next, &set->catchall_list, list) {
 		if (catchall->elem == elem->priv) {
-			list_del_rcu(&catchall->list);
-			kfree_rcu(catchall, rcu);
+			nft_setelem_catchall_destroy(catchall);
 			break;
 		}
 	}
@@ -9268,11 +9273,12 @@  static struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc,
 						  unsigned int gc_seq,
 						  bool sync)
 {
-	struct nft_set_elem_catchall *catchall;
+	struct nft_set_elem_catchall *catchall, *next;
 	const struct nft_set *set = gc->set;
+	struct nft_set_elem *elem;
 	struct nft_set_ext *ext;
 
-	list_for_each_entry_rcu(catchall, &set->catchall_list, list) {
+	list_for_each_entry_safe(catchall, next, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
 
 		if (!nft_set_elem_expired(ext))
@@ -9290,7 +9296,13 @@  static struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc,
 		if (!gc)
 			return NULL;
 
-		nft_trans_gc_elem_add(gc, catchall->elem);
+		elem = catchall->elem;
+		if (sync) {
+			nft_setelem_data_deactivate(gc->net, gc->set, elem);
+			nft_setelem_catchall_destroy(catchall);
+		}
+
+		nft_trans_gc_elem_add(gc, elem->priv);
 	}
 
 	return gc;