diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
index cbbde0f73a08..a77fafbc31cf 100644
--- a/net/mctp/af_mctp.c
+++ b/net/mctp/af_mctp.c
@@ -288,6 +288,7 @@ static void mctp_sk_unhash(struct sock *sk)
 
 		kfree_rcu(key, rcu);
 	}
+	sock_set_flag(sk, SOCK_DEAD);
 	spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
 
 	synchronize_rcu();
diff --git a/net/mctp/route.c b/net/mctp/route.c
index 6aebb4a3eded..89e67399249b 100644
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -135,6 +135,11 @@ static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk)
 
 	spin_lock_irqsave(&net->mctp.keys_lock, flags);
 
+	if (sock_flag(&msk->sk, SOCK_DEAD)) {
+		rc = -EINVAL;
+		goto out_unlock;
+	}
+
 	hlist_for_each_entry(tmp, &net->mctp.keys, hlist) {
 		if (mctp_key_match(tmp, key->local_addr, key->peer_addr,
 				   key->tag)) {
@@ -148,6 +153,7 @@ static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk)
 		hlist_add_head(&key->sklist, &msk->keys);
 	}
 
+out_unlock:
 	spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
 
 	return rc;