Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Cross-merge bpf fixes after downstream PR.

No conflicts.

Adjacent changes in:
Auto-merging include/linux/bpf.h
Auto-merging include/linux/bpf_verifier.h
Auto-merging kernel/bpf/btf.c
Auto-merging kernel/bpf/verifier.c
Auto-merging kernel/trace/bpf_trace.c
Auto-merging tools/testing/selftests/bpf/progs/test_tp_btf_nullable.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 19 insertions, 1 deletions

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index ae34ac818cda..b5cd3ae4f04c 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -449,6 +449,21 @@ out_free:
 	goto out;
 }
 
+static LLIST_HEAD(defer_free_list);
+
+static void net_complete_free(void)
+{
+	struct llist_node *kill_list;
+	struct net *net, *next;
+
+	/* Get the list of namespaces to free from last round. */
+	kill_list = llist_del_all(&defer_free_list);
+
+	llist_for_each_entry_safe(net, next, kill_list, defer_free_list)
+		kmem_cache_free(net_cachep, net);
+
+}
+
 static void net_free(struct net *net)
 {
 	if (refcount_dec_and_test(&net->passive)) {
@@ -457,7 +472,8 @@ static void net_free(struct net *net)
 		/* There should not be any trackers left there. */
 		ref_tracker_dir_exit(&net->notrefcnt_tracker);
 
-		kmem_cache_free(net_cachep, net);
+		/* Wait for an extra rcu_barrier() before final free. */
+		llist_add(&net->defer_free_list, &defer_free_list);
 	}
 }
 
@@ -642,6 +658,8 @@ static void cleanup_net(struct work_struct *work)
 	 */
 	rcu_barrier();
 
+	net_complete_free();
+
 	/* Finally it is safe to free my network namespace structure */
 	list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
 		list_del_init(&net->exit_list);