[PATCH 5.2 21/85] net: sock_map, fix missing ulp check in sock hash case

[Greg Kroah-Hartman]

From: John Fastabend <john.fastabend@xxxxxxxxx>

[ Upstream commit 44580a0118d3ede95fec4dce32df5f75f73cd663 ]

sock_map and ULP only work together when ULP is loaded after the sock
map is loaded. In the sock_map case we added a check for this to fail
the load if ULP is already set. However, we missed the check on the
sock_hash side.

Add a ULP check to the sock_hash update path.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Reported-by: syzbot+7a6ee4d0078eac6bf782@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: John Fastabend <john.fastabend@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/core/sock_map.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -661,6 +661,7 @@ static int sock_hash_update_common(struc
 				   struct sock *sk, u64 flags)
 {
 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	u32 key_size = map->key_size, hash;
 	struct bpf_htab_elem *elem, *elem_new;
 	struct bpf_htab_bucket *bucket;
@@ -671,6 +672,8 @@ static int sock_hash_update_common(struc
 	WARN_ON_ONCE(!rcu_read_lock_held());
 	if (unlikely(flags > BPF_EXIST))
 		return -EINVAL;
+	if (unlikely(icsk->icsk_ulp_data))
+		return -EINVAL;
 
 	link = sk_psock_init_link();
 	if (!link)