Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2023-12-21

Hi David, hi Jakub, hi Paolo, hi Eric,

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

We've added 3 non-merge commits during the last 5 day(s) which contain
a total of 4 files changed, 45 insertions(+).

The main changes are:

1) Fix a syzkaller splat which triggered an oob issue in bpf_link_show_fdinfo(),
   from Jiri Olsa.

2) Fix another syzkaller-found issue which triggered a NULL pointer dereference
   in BPF sockmap for unconnected unix sockets, from John Fastabend.

bpf-for-netdev

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Add missing BPF_LINK_TYPE invocations
  bpf: sockmap, test for unconnected af_unix sock
  bpf: syzkaller found null ptr deref in unix_bpf proto add
====================

Link: https://lore.kernel.org/r/20231221104844.1374-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Paolo Abeni

include/linux/bpf_types.h

@@ -142,9 +142,13 @@ BPF_LINK_TYPE(BPF_LINK_TYPE_ITER, iter)
 #ifdef CONFIG_NET
 BPF_LINK_TYPE(BPF_LINK_TYPE_NETNS, netns)
 BPF_LINK_TYPE(BPF_LINK_TYPE_XDP, xdp)
+BPF_LINK_TYPE(BPF_LINK_TYPE_NETFILTER, netfilter)
+BPF_LINK_TYPE(BPF_LINK_TYPE_TCX, tcx)
+BPF_LINK_TYPE(BPF_LINK_TYPE_NETKIT, netkit)
 #endif
 #ifdef CONFIG_PERF_EVENTS
 BPF_LINK_TYPE(BPF_LINK_TYPE_PERF_EVENT, perf)
 #endif
 BPF_LINK_TYPE(BPF_LINK_TYPE_KPROBE_MULTI, kprobe_multi)
 BPF_LINK_TYPE(BPF_LINK_TYPE_STRUCT_OPS, struct_ops)
+BPF_LINK_TYPE(BPF_LINK_TYPE_UPROBE_MULTI, uprobe_multi)

include/net/sock.h

@@ -2799,6 +2799,11 @@ static inline bool sk_is_tcp(const struct sock *sk)
 	return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP;
 }
 
+static inline bool sk_is_stream_unix(const struct sock *sk)
+{
+	return sk->sk_family == AF_UNIX && sk->sk_type == SOCK_STREAM;
+}
+
 /**
  * sk_eat_skb - Release a skb if it is no longer needed
  * @sk: socket to eat this skb from

net/core/sock_map.c

@@ -536,6 +536,8 @@ static bool sock_map_sk_state_allowed(const struct sock *sk)
 {
 	if (sk_is_tcp(sk))
 		return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
+	if (sk_is_stream_unix(sk))
+		return (1 << sk->sk_state) & TCPF_ESTABLISHED;
 	return true;
 }
 

tools/testing/selftests/bpf/prog_tests/sockmap_basic.c

@@ -524,6 +524,37 @@ static void test_sockmap_skb_verdict_peek(void)
 	test_sockmap_pass_prog__destroy(pass);
 }
 
+static void test_sockmap_unconnected_unix(void)
+{
+	int err, map, stream = 0, dgram = 0, zero = 0;
+	struct test_sockmap_pass_prog *skel;
+
+	skel = test_sockmap_pass_prog__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		return;
+
+	map = bpf_map__fd(skel->maps.sock_map_rx);
+
+	stream = xsocket(AF_UNIX, SOCK_STREAM, 0);
+	if (stream < 0)
+		return;
+
+	dgram = xsocket(AF_UNIX, SOCK_DGRAM, 0);
+	if (dgram < 0) {
+		close(stream);
+		return;
+	}
+
+	err = bpf_map_update_elem(map, &zero, &stream, BPF_ANY);
+	ASSERT_ERR(err, "bpf_map_update_elem(stream)");
+
+	err = bpf_map_update_elem(map, &zero, &dgram, BPF_ANY);
+	ASSERT_OK(err, "bpf_map_update_elem(dgram)");
+
+	close(stream);
+	close(dgram);
+}
+
 void test_sockmap_basic(void)
 {
 	if (test__start_subtest("sockmap create_update_free"))
@@ -566,4 +597,7 @@ void test_sockmap_basic(void)
 		test_sockmap_skb_verdict_fionread(false);
 	if (test__start_subtest("sockmap skb_verdict msg_f_peek"))
 		test_sockmap_skb_verdict_peek();
+
+	if (test__start_subtest("sockmap unconnected af_unix"))
+		test_sockmap_unconnected_unix();
 }