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

Daniel Borkmann says:

====================
pull-request: bpf 2023-11-30

We've added 5 non-merge commits during the last 7 day(s) which contain
a total of 10 files changed, 66 insertions(+), 15 deletions(-).

The main changes are:

1) Fix AF_UNIX splat from use after free in BPF sockmap,
   from John Fastabend.

2) Fix a syzkaller splat in netdevsim by properly handling offloaded
   programs (and not device-bound ones), from Stanislav Fomichev.

3) Fix bpf_mem_cache_alloc_flags() to initialize the allocation hint,
   from Hou Tao.

4) Fix netkit by rejecting IFLA_NETKIT_PEER_INFO in changelink,
   from Daniel Borkmann.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, sockmap: Add af_unix test with both sockets in map
  bpf, sockmap: af_unix stream sockets need to hold ref for pair sock
  netkit: Reject IFLA_NETKIT_PEER_INFO in netkit_change_link
  bpf: Add missed allocation hint for bpf_mem_cache_alloc_flags()
  netdevsim: Don't accept device bound programs
====================

Link: https://lore.kernel.org/r/20231129234916.16128-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c
index 2f9d8271c6ec..7ea7c3a0d0d0 100644
--- a/net/unix/unix_bpf.c
+++ b/net/unix/unix_bpf.c
@@ -159,12 +159,17 @@ int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool re
 
 int unix_stream_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
 {
+	struct sock *sk_pair;
+
 	if (restore) {
 		sk->sk_write_space = psock->saved_write_space;
 		sock_replace_proto(sk, psock->sk_proto);
 		return 0;
 	}
 
+	sk_pair = unix_peer(sk);
+	sock_hold(sk_pair);
+	psock->sk_pair = sk_pair;
 	unix_stream_bpf_check_needs_rebuild(psock->sk_proto);
 	sock_replace_proto(sk, &unix_stream_bpf_prot);
 	return 0;