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

Daniel Borkmann says:

====================
pull-request: bpf 2020-05-22

The following pull-request contains BPF updates for your *net* tree.

We've added 3 non-merge commits during the last 3 day(s) which contain
a total of 5 files changed, 69 insertions(+), 11 deletions(-).

The main changes are:

1) Fix to reject mmap()'ing read-only array maps as writable since BPF verifier
   relies on such map content to be frozen, from Andrii Nakryiko.

2) Fix breaking audit from secid_to_secctx() LSM hook by avoiding to use
   call_int_hook() since this hook is not stackable, from KP Singh.

3) Fix BPF flow dissector program ref leak on netns cleanup, from Jakub Sitnicki.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 5 deletions

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 3eff84824c8b..5dceed467f64 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -160,12 +160,10 @@ out:
 	return ret;
 }
 
-int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
+static int flow_dissector_bpf_prog_detach(struct net *net)
 {
 	struct bpf_prog *attached;
-	struct net *net;
 
-	net = current->nsproxy->net_ns;
 	mutex_lock(&flow_dissector_mutex);
 	attached = rcu_dereference_protected(net->flow_dissector_prog,
 					     lockdep_is_held(&flow_dissector_mutex));
@@ -179,6 +177,24 @@ int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
 	return 0;
 }
 
+int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
+{
+	return flow_dissector_bpf_prog_detach(current->nsproxy->net_ns);
+}
+
+static void __net_exit flow_dissector_pernet_pre_exit(struct net *net)
+{
+	/* We're not racing with attach/detach because there are no
+	 * references to netns left when pre_exit gets called.
+	 */
+	if (rcu_access_pointer(net->flow_dissector_prog))
+		flow_dissector_bpf_prog_detach(net);
+}
+
+static struct pernet_operations flow_dissector_pernet_ops __net_initdata = {
+	.pre_exit = flow_dissector_pernet_pre_exit,
+};
+
 /**
  * __skb_flow_get_ports - extract the upper layer ports and return them
  * @skb: sk_buff to extract the ports from
@@ -1836,7 +1852,7 @@ static int __init init_default_flow_dissectors(void)
 	skb_flow_dissector_init(&flow_keys_basic_dissector,
 				flow_keys_basic_dissector_keys,
 				ARRAY_SIZE(flow_keys_basic_dissector_keys));
-	return 0;
-}
 
+	return register_pernet_subsys(&flow_dissector_pernet_ops);
+}
 core_initcall(init_default_flow_dissectors);