[net PATCH] net: sock_map, fix missing ulp check in sock hash case

[John Fastabend]

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+7a6ee4d0078eac6bf...@syzkaller.appspotmail.com
Signed-off-by: John Fastabend <john.fastab...@gmail.com>
---
 net/core/sock_map.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 1330a74..50916f9 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -656,6 +656,7 @@ static int sock_hash_update_common(struct bpf_map *map, 
void *key,
                                   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;
@@ -666,6 +667,8 @@ static int sock_hash_update_common(struct bpf_map *map, 
void *key,
        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)