netfilter: nft_set_pipapo: call nft_trans_gc_queue_sync() in catchall GC

jira VULN-430
cve CVE-2023-4244
commit-author Pablo Neira Ayuso <pablo@netfilter.org>
commit 4a9e12e

pipapo needs to enqueue GC transactions for catchall elements through
nft_trans_gc_queue_sync(). Add nft_trans_gc_catchall_sync() and
nft_trans_gc_catchall_async() to handle GC transaction queueing
accordingly.

Fixes: 5f68718 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Fixes: f6c383b ("netfilter: nf_tables: adapt set backend to use GC transaction API")
	Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
(cherry picked from commit 4a9e12e)
	Signed-off-by: Marcin Wcisło <marcin.wcislo@conclusive.pl>

Author: pvts-mat

include/net/netfilter/nf_tables.h

@@ -1629,8 +1629,9 @@ void nft_trans_gc_queue_sync_done(struct nft_trans_gc *trans);
 
 void nft_trans_gc_elem_add(struct nft_trans_gc *gc, void *priv);
 
-struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc,
-					   unsigned int gc_seq);
+struct nft_trans_gc *nft_trans_gc_catchall_async(struct nft_trans_gc *gc,
+						 unsigned int gc_seq);
+struct nft_trans_gc *nft_trans_gc_catchall_sync(struct nft_trans_gc *gc);
 
 void nft_setelem_data_deactivate(const struct net *net,
 				 const struct nft_set *set,

net/netfilter/nf_tables_api.c

@@ -9256,8 +9256,9 @@ void nft_trans_gc_queue_sync_done(struct nft_trans_gc *trans)
 	call_rcu(&trans->rcu, nft_trans_gc_trans_free);
 }
 
-struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc,
-					   unsigned int gc_seq)
+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;
 	const struct nft_set *set = gc->set;
@@ -9273,7 +9274,11 @@ struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc,
 
 		nft_set_elem_dead(ext);
 dead_elem:
-		gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
+		if (sync)
+			gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
+		else
+			gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
+
 		if (!gc)
 			return NULL;
 
@@ -9283,6 +9288,17 @@ struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc,
 	return gc;
 }
 
+struct nft_trans_gc *nft_trans_gc_catchall_async(struct nft_trans_gc *gc,
+						 unsigned int gc_seq)
+{
+	return nft_trans_gc_catchall(gc, gc_seq, false);
+}
+
+struct nft_trans_gc *nft_trans_gc_catchall_sync(struct nft_trans_gc *gc)
+{
+	return nft_trans_gc_catchall(gc, 0, true);
+}
+
 static void nf_tables_module_autoload_cleanup(struct net *net)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);

net/netfilter/nft_set_hash.c

@@ -372,7 +372,7 @@ static void nft_rhash_gc(struct work_struct *work)
 		nft_trans_gc_elem_add(gc, he);
 	}
 
-	gc = nft_trans_gc_catchall(gc, gc_seq);
+	gc = nft_trans_gc_catchall_async(gc, gc_seq);
 
 try_later:
 	/* catchall list iteration requires rcu read side lock. */

net/netfilter/nft_set_pipapo.c

@@ -1611,7 +1611,7 @@ static void pipapo_gc(const struct nft_set *_set, struct nft_pipapo_match *m)
 		}
 	}
 
-	gc = nft_trans_gc_catchall(gc, 0);
+	gc = nft_trans_gc_catchall_sync(gc);
 	if (gc) {
 		nft_trans_gc_queue_sync_done(gc);
 		priv->last_gc = jiffies;

net/netfilter/nft_set_rbtree.c

@@ -670,7 +670,7 @@ static void nft_rbtree_gc(struct work_struct *work)
 		nft_trans_gc_elem_add(gc, rbe);
 	}
 
-	gc = nft_trans_gc_catchall(gc, gc_seq);
+	gc = nft_trans_gc_catchall_async(gc, gc_seq);
 
 try_later:
 	write_seqcount_end(&priv->count);