5 files changed, 351 insertions, 86 deletions

diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
index de52a9191da0..9b12ca97f412 100644
--- a/net/mctp/af_mctp.c
+++ b/net/mctp/af_mctp.c
@@ -486,6 +486,9 @@ static int mctp_ioctl_droptag(struct mctp_sock *msk, bool tagv2,
 	tag = ctl.tag & MCTP_TAG_MASK;
 	rc = -EINVAL;
 
+	if (ctl.peer_addr == MCTP_ADDR_NULL)
+		ctl.peer_addr = MCTP_ADDR_ANY;
+
 	spin_lock_irqsave(&net->mctp.keys_lock, flags);
 	hlist_for_each_entry_safe(key, tmp, &msk->keys, sklist) {
 		/* we do an irqsave here, even though we know the irq state,
@@ -627,6 +630,9 @@ static int mctp_sk_hash(struct sock *sk)
 {
 	struct net *net = sock_net(sk);
 
+	/* Bind lookup runs under RCU, remain live during that. */
+	sock_set_flag(sk, SOCK_RCU_FREE);
+
 	mutex_lock(&net->mctp.bind_lock);
 	sk_add_node_rcu(sk, &net->mctp.binds);
 	mutex_unlock(&net->mctp.bind_lock);
@@ -660,7 +666,7 @@ static void mctp_sk_unhash(struct sock *sk)
 	 * keys), stop any pending expiry events. the timer cannot be re-queued
 	 * as the sk is no longer observable
 	 */
-	del_timer_sync(&msk->key_expiry);
+	timer_delete_sync(&msk->key_expiry);
 }
 
 static void mctp_sk_destruct(struct sock *sk)
@@ -753,10 +759,14 @@ static __init int mctp_init(void)
 	if (rc)
 		goto err_unreg_routes;
 
-	mctp_device_init();
+	rc = mctp_device_init();
+	if (rc)
+		goto err_unreg_neigh;
 
 	return 0;
 
+err_unreg_neigh:
+	mctp_neigh_exit();
 err_unreg_routes:
 	mctp_routes_exit();
 err_unreg_proto:
diff --git a/net/mctp/device.c b/net/mctp/device.c
index acb97b257428..4d404edd7446 100644
--- a/net/mctp/device.c
+++ b/net/mctp/device.c
@@ -20,8 +20,7 @@
 #include <net/sock.h>
 
 struct mctp_dump_cb {
-	int h;
-	int idx;
+	unsigned long ifindex;
 	size_t a_idx;
 };
 
@@ -115,43 +114,36 @@ static int mctp_dump_addrinfo(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct mctp_dump_cb *mcb = (void *)cb->ctx;
 	struct net *net = sock_net(skb->sk);
-	struct hlist_head *head;
 	struct net_device *dev;
 	struct ifaddrmsg *hdr;
 	struct mctp_dev *mdev;
-	int ifindex;
-	int idx = 0, rc;
-
-	hdr = nlmsg_data(cb->nlh);
-	// filter by ifindex if requested
-	ifindex = hdr->ifa_index;
+	int ifindex = 0, rc;
+
+	/* Filter by ifindex if a header is provided */
+	hdr = nlmsg_payload(cb->nlh, sizeof(*hdr));
+	if (hdr) {
+		ifindex = hdr->ifa_index;
+	} else {
+		if (cb->strict_check) {
+			NL_SET_ERR_MSG(cb->extack, "mctp: Invalid header for addr dump request");
+			return -EINVAL;
+		}
+	}
 
 	rcu_read_lock();
-	for (; mcb->h < NETDEV_HASHENTRIES; mcb->h++, mcb->idx = 0) {
-		idx = 0;
-		head = &net->dev_index_head[mcb->h];
-		hlist_for_each_entry_rcu(dev, head, index_hlist) {
-			if (idx >= mcb->idx &&
-			    (ifindex == 0 || ifindex == dev->ifindex)) {
-				mdev = __mctp_dev_get(dev);
-				if (mdev) {
-					rc = mctp_dump_dev_addrinfo(mdev,
-								    skb, cb);
-					mctp_dev_put(mdev);
-					// Error indicates full buffer, this
-					// callback will get retried.
-					if (rc < 0)
-						goto out;
-				}
-			}
-			idx++;
-			// reset for next iteration
-			mcb->a_idx = 0;
-		}
+	for_each_netdev_dump(net, dev, mcb->ifindex) {
+		if (ifindex && ifindex != dev->ifindex)
+			continue;
+		mdev = __mctp_dev_get(dev);
+		if (!mdev)
+			continue;
+		rc = mctp_dump_dev_addrinfo(mdev, skb, cb);
+		mctp_dev_put(mdev);
+		if (rc < 0)
+			break;
+		mcb->a_idx = 0;
 	}
-out:
 	rcu_read_unlock();
-	mcb->idx = idx;
 
 	return skb->len;
 }
@@ -371,6 +363,8 @@ static int mctp_fill_link_af(struct sk_buff *skb,
 		return -ENODATA;
 	if (nla_put_u32(skb, IFLA_MCTP_NET, mdev->net))
 		return -EMSGSIZE;
+	if (nla_put_u8(skb, IFLA_MCTP_PHYS_BINDING, mdev->binding))
+		return -EMSGSIZE;
 	return 0;
 }
 
@@ -385,6 +379,7 @@ static size_t mctp_get_link_af_size(const struct net_device *dev,
 	if (!mdev)
 		return 0;
 	ret = nla_total_size(4); /* IFLA_MCTP_NET */
+	ret += nla_total_size(1); /* IFLA_MCTP_PHYS_BINDING */
 	mctp_dev_put(mdev);
 	return ret;
 }
@@ -480,7 +475,8 @@ static int mctp_dev_notify(struct notifier_block *this, unsigned long event,
 }
 
 static int mctp_register_netdevice(struct net_device *dev,
-				   const struct mctp_netdev_ops *ops)
+				   const struct mctp_netdev_ops *ops,
+				   enum mctp_phys_binding binding)
 {
 	struct mctp_dev *mdev;
 
@@ -489,17 +485,19 @@ static int mctp_register_netdevice(struct net_device *dev,
 		return PTR_ERR(mdev);
 
 	mdev->ops = ops;
+	mdev->binding = binding;
 
 	return register_netdevice(dev);
 }
 
 int mctp_register_netdev(struct net_device *dev,
-			 const struct mctp_netdev_ops *ops)
+			 const struct mctp_netdev_ops *ops,
+			 enum mctp_phys_binding binding)
 {
 	int rc;
 
 	rtnl_lock();
-	rc = mctp_register_netdevice(dev, ops);
+	rc = mctp_register_netdevice(dev, ops, binding);
 	rtnl_unlock();
 
 	return rc;
@@ -524,25 +522,40 @@ static struct notifier_block mctp_dev_nb = {
 	.priority = ADDRCONF_NOTIFY_PRIORITY,
 };
 
-void __init mctp_device_init(void)
+static const struct rtnl_msg_handler mctp_device_rtnl_msg_handlers[] = {
+	{.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_NEWADDR,
+	 .doit = mctp_rtm_newaddr},
+	{.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_DELADDR,
+	 .doit = mctp_rtm_deladdr},
+	{.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_GETADDR,
+	 .dumpit = mctp_dump_addrinfo},
+};
+
+int __init mctp_device_init(void)
 {
+	int err;
+
 	register_netdevice_notifier(&mctp_dev_nb);
 
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETADDR,
-			     NULL, mctp_dump_addrinfo, 0);
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWADDR,
-			     mctp_rtm_newaddr, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELADDR,
-			     mctp_rtm_deladdr, NULL, 0);
-	rtnl_af_register(&mctp_af_ops);
+	err = rtnl_af_register(&mctp_af_ops);
+	if (err)
+		goto err_notifier;
+
+	err = rtnl_register_many(mctp_device_rtnl_msg_handlers);
+	if (err)
+		goto err_af;
+
+	return 0;
+err_af:
+	rtnl_af_unregister(&mctp_af_ops);
+err_notifier:
+	unregister_netdevice_notifier(&mctp_dev_nb);
+	return err;
 }
 
 void __exit mctp_device_exit(void)
 {
+	rtnl_unregister_many(mctp_device_rtnl_msg_handlers);
 	rtnl_af_unregister(&mctp_af_ops);
-	rtnl_unregister(PF_MCTP, RTM_DELADDR);
-	rtnl_unregister(PF_MCTP, RTM_NEWADDR);
-	rtnl_unregister(PF_MCTP, RTM_GETADDR);
-
 	unregister_netdevice_notifier(&mctp_dev_nb);
 }
diff --git a/net/mctp/neigh.c b/net/mctp/neigh.c
index ffa0f9e0983f..05b899f22d90 100644
--- a/net/mctp/neigh.c
+++ b/net/mctp/neigh.c
@@ -250,7 +250,10 @@ static int mctp_rtm_getneigh(struct sk_buff *skb, struct netlink_callback *cb)
 		int idx;
 	} *cbctx = (void *)cb->ctx;
 
-	ndmsg = nlmsg_data(cb->nlh);
+	ndmsg = nlmsg_payload(cb->nlh, sizeof(*ndmsg));
+	if (!ndmsg)
+		return -EINVAL;
+
 	req_ifindex = ndmsg->ndm_ifindex;
 
 	idx = 0;
@@ -322,22 +325,29 @@ static struct pernet_operations mctp_net_ops = {
 	.exit = mctp_neigh_net_exit,
 };
 
+static const struct rtnl_msg_handler mctp_neigh_rtnl_msg_handlers[] = {
+	{THIS_MODULE, PF_MCTP, RTM_NEWNEIGH, mctp_rtm_newneigh, NULL, 0},
+	{THIS_MODULE, PF_MCTP, RTM_DELNEIGH, mctp_rtm_delneigh, NULL, 0},
+	{THIS_MODULE, PF_MCTP, RTM_GETNEIGH, NULL, mctp_rtm_getneigh, 0},
+};
+
 int __init mctp_neigh_init(void)
 {
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWNEIGH,
-			     mctp_rtm_newneigh, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELNEIGH,
-			     mctp_rtm_delneigh, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETNEIGH,
-			     NULL, mctp_rtm_getneigh, 0);
-
-	return register_pernet_subsys(&mctp_net_ops);
+	int err;
+
+	err = register_pernet_subsys(&mctp_net_ops);
+	if (err)
+		return err;
+
+	err = rtnl_register_many(mctp_neigh_rtnl_msg_handlers);
+	if (err)
+		unregister_pernet_subsys(&mctp_net_ops);
+
+	return err;
 }
 
-void __exit mctp_neigh_exit(void)
+void mctp_neigh_exit(void)
 {
+	rtnl_unregister_many(mctp_neigh_rtnl_msg_handlers);
 	unregister_pernet_subsys(&mctp_net_ops);
-	rtnl_unregister(PF_MCTP, RTM_GETNEIGH);
-	rtnl_unregister(PF_MCTP, RTM_DELNEIGH);
-	rtnl_unregister(PF_MCTP, RTM_NEWNEIGH);
 }
diff --git a/net/mctp/route.c b/net/mctp/route.c
index eefd7834d9a0..d9c8e5a5f9ce 100644
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -313,8 +313,10 @@ static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev)
 
 	key = flow->key;
 
-	if (WARN_ON(key->dev && key->dev != dev))
+	if (key->dev) {
+		WARN_ON(key->dev != dev);
 		return;
+	}
 
 	mctp_dev_set_key(dev, key);
 }
@@ -332,8 +334,14 @@ static int mctp_frag_queue(struct mctp_sk_key *key, struct sk_buff *skb)
 		& MCTP_HDR_SEQ_MASK;
 
 	if (!key->reasm_head) {
-		key->reasm_head = skb;
-		key->reasm_tailp = &(skb_shinfo(skb)->frag_list);
+		/* Since we're manipulating the shared frag_list, ensure it isn't
+		 * shared with any other SKBs.
+		 */
+		key->reasm_head = skb_unshare(skb, GFP_ATOMIC);
+		if (!key->reasm_head)
+			return -ENOMEM;
+
+		key->reasm_tailp = &(skb_shinfo(key->reasm_head)->frag_list);
 		key->last_seq = this_seq;
 		return 0;
 	}
@@ -374,8 +382,13 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 	msk = NULL;
 	rc = -EINVAL;
 
-	/* we may be receiving a locally-routed packet; drop source sk
-	 * accounting
+	/* We may be receiving a locally-routed packet; drop source sk
+	 * accounting.
+	 *
+	 * From here, we will either queue the skb - either to a frag_queue, or
+	 * to a receiving socket. When that succeeds, we clear the skb pointer;
+	 * a non-NULL skb on exit will be otherwise unowned, and hence
+	 * kfree_skb()-ed.
 	 */
 	skb_orphan(skb);
 
@@ -434,7 +447,9 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 		 * pending key.
 		 */
 		if (flags & MCTP_HDR_FLAG_EOM) {
-			sock_queue_rcv_skb(&msk->sk, skb);
+			rc = sock_queue_rcv_skb(&msk->sk, skb);
+			if (!rc)
+				skb = NULL;
 			if (key) {
 				/* we've hit a pending reassembly; not much we
 				 * can do but drop it
@@ -443,7 +458,6 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 						   MCTP_TRACE_KEY_REPLIED);
 				key = NULL;
 			}
-			rc = 0;
 			goto out_unlock;
 		}
 
@@ -470,8 +484,10 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 			 * this function.
 			 */
 			rc = mctp_key_add(key, msk);
-			if (!rc)
+			if (!rc) {
 				trace_mctp_key_acquire(key);
+				skb = NULL;
+			}
 
 			/* we don't need to release key->lock on exit, so
 			 * clean up here and suppress the unlock via
@@ -489,6 +505,8 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 				key = NULL;
 			} else {
 				rc = mctp_frag_queue(key, skb);
+				if (!rc)
+					skb = NULL;
 			}
 		}
 
@@ -503,12 +521,19 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 		else
 			rc = mctp_frag_queue(key, skb);
 
+		if (rc)
+			goto out_unlock;
+
+		/* we've queued; the queue owns the skb now */
+		skb = NULL;
+
 		/* end of message? deliver to socket, and we're done with
 		 * the reassembly/response key
 		 */
-		if (!rc && flags & MCTP_HDR_FLAG_EOM) {
-			sock_queue_rcv_skb(key->sk, key->reasm_head);
-			key->reasm_head = NULL;
+		if (flags & MCTP_HDR_FLAG_EOM) {
+			rc = sock_queue_rcv_skb(key->sk, key->reasm_head);
+			if (!rc)
+				key->reasm_head = NULL;
 			__mctp_key_done_in(key, net, f, MCTP_TRACE_KEY_REPLIED);
 			key = NULL;
 		}
@@ -527,8 +552,7 @@ out_unlock:
 	if (any_key)
 		mctp_key_unref(any_key);
 out:
-	if (rc)
-		kfree_skb(skb);
+	kfree_skb(skb);
 	return rc;
 }
 
@@ -1474,26 +1498,39 @@ static struct pernet_operations mctp_net_ops = {
 	.exit = mctp_routes_net_exit,
 };
 
+static const struct rtnl_msg_handler mctp_route_rtnl_msg_handlers[] = {
+	{THIS_MODULE, PF_MCTP, RTM_NEWROUTE, mctp_newroute, NULL, 0},
+	{THIS_MODULE, PF_MCTP, RTM_DELROUTE, mctp_delroute, NULL, 0},
+	{THIS_MODULE, PF_MCTP, RTM_GETROUTE, NULL, mctp_dump_rtinfo, 0},
+};
+
 int __init mctp_routes_init(void)
 {
+	int err;
+
 	dev_add_pack(&mctp_packet_type);
 
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETROUTE,
-			     NULL, mctp_dump_rtinfo, 0);
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWROUTE,
-			     mctp_newroute, NULL, 0);
-	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELROUTE,
-			     mctp_delroute, NULL, 0);
+	err = register_pernet_subsys(&mctp_net_ops);
+	if (err)
+		goto err_pernet;
+
+	err = rtnl_register_many(mctp_route_rtnl_msg_handlers);
+	if (err)
+		goto err_rtnl;
+
+	return 0;
 
-	return register_pernet_subsys(&mctp_net_ops);
+err_rtnl:
+	unregister_pernet_subsys(&mctp_net_ops);
+err_pernet:
+	dev_remove_pack(&mctp_packet_type);
+	return err;
 }
 
 void mctp_routes_exit(void)
 {
+	rtnl_unregister_many(mctp_route_rtnl_msg_handlers);
 	unregister_pernet_subsys(&mctp_net_ops);
-	rtnl_unregister(PF_MCTP, RTM_DELROUTE);
-	rtnl_unregister(PF_MCTP, RTM_NEWROUTE);
-	rtnl_unregister(PF_MCTP, RTM_GETROUTE);
 	dev_remove_pack(&mctp_packet_type);
 }
 
diff --git a/net/mctp/test/route-test.c b/net/mctp/test/route-test.c
index 77e5dd422258..06c1897b685a 100644
--- a/net/mctp/test/route-test.c
+++ b/net/mctp/test/route-test.c
@@ -366,7 +366,7 @@ static void mctp_test_route_input_sk(struct kunit *test)
 
 		skb2 = skb_recv_datagram(sock->sk, MSG_DONTWAIT, &rc);
 		KUNIT_EXPECT_NOT_ERR_OR_NULL(test, skb2);
-		KUNIT_EXPECT_EQ(test, skb->len, 1);
+		KUNIT_EXPECT_EQ(test, skb2->len, 1);
 
 		skb_free_datagram(sock->sk, skb2);
 
@@ -837,6 +837,198 @@ static void mctp_test_route_input_multiple_nets_key(struct kunit *test)
 	mctp_test_route_input_multiple_nets_key_fini(test, &t2);
 }
 
+/* Input route to socket, using a single-packet message, where sock delivery
+ * fails. Ensure we're handling the failure appropriately.
+ */
+static void mctp_test_route_input_sk_fail_single(struct kunit *test)
+{
+	const struct mctp_hdr hdr = RX_HDR(1, 10, 8, FL_S | FL_E | FL_TO);
+	struct mctp_test_route *rt;
+	struct mctp_test_dev *dev;
+	struct socket *sock;
+	struct sk_buff *skb;
+	int rc;
+
+	__mctp_route_test_init(test, &dev, &rt, &sock, MCTP_NET_ANY);
+
+	/* No rcvbuf space, so delivery should fail. __sock_set_rcvbuf will
+	 * clamp the minimum to SOCK_MIN_RCVBUF, so we open-code this.
+	 */
+	lock_sock(sock->sk);
+	WRITE_ONCE(sock->sk->sk_rcvbuf, 0);
+	release_sock(sock->sk);
+
+	skb = mctp_test_create_skb(&hdr, 10);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, skb);
+	skb_get(skb);
+
+	mctp_test_skb_set_dev(skb, dev);
+
+	/* do route input, which should fail */
+	rc = mctp_route_input(&rt->rt, skb);
+	KUNIT_EXPECT_NE(test, rc, 0);
+
+	/* we should hold the only reference to skb */
+	KUNIT_EXPECT_EQ(test, refcount_read(&skb->users), 1);
+	kfree_skb(skb);
+
+	__mctp_route_test_fini(test, dev, rt, sock);
+}
+
+/* Input route to socket, using a fragmented message, where sock delivery fails.
+ */
+static void mctp_test_route_input_sk_fail_frag(struct kunit *test)
+{
+	const struct mctp_hdr hdrs[2] = { RX_FRAG(FL_S, 0), RX_FRAG(FL_E, 1) };
+	struct mctp_test_route *rt;
+	struct mctp_test_dev *dev;
+	struct sk_buff *skbs[2];
+	struct socket *sock;
+	unsigned int i;
+	int rc;
+
+	__mctp_route_test_init(test, &dev, &rt, &sock, MCTP_NET_ANY);
+
+	lock_sock(sock->sk);
+	WRITE_ONCE(sock->sk->sk_rcvbuf, 0);
+	release_sock(sock->sk);
+
+	for (i = 0; i < ARRAY_SIZE(skbs); i++) {
+		skbs[i] = mctp_test_create_skb(&hdrs[i], 10);
+		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, skbs[i]);
+		skb_get(skbs[i]);
+
+		mctp_test_skb_set_dev(skbs[i], dev);
+	}
+
+	/* first route input should succeed, we're only queueing to the
+	 * frag list
+	 */
+	rc = mctp_route_input(&rt->rt, skbs[0]);
+	KUNIT_EXPECT_EQ(test, rc, 0);
+
+	/* final route input should fail to deliver to the socket */
+	rc = mctp_route_input(&rt->rt, skbs[1]);
+	KUNIT_EXPECT_NE(test, rc, 0);
+
+	/* we should hold the only reference to both skbs */
+	KUNIT_EXPECT_EQ(test, refcount_read(&skbs[0]->users), 1);
+	kfree_skb(skbs[0]);
+
+	KUNIT_EXPECT_EQ(test, refcount_read(&skbs[1]->users), 1);
+	kfree_skb(skbs[1]);
+
+	__mctp_route_test_fini(test, dev, rt, sock);
+}
+
+/* Input route to socket, using a fragmented message created from clones.
+ */
+static void mctp_test_route_input_cloned_frag(struct kunit *test)
+{
+	/* 5 packet fragments, forming 2 complete messages */
+	const struct mctp_hdr hdrs[5] = {
+		RX_FRAG(FL_S, 0),
+		RX_FRAG(0, 1),
+		RX_FRAG(FL_E, 2),
+		RX_FRAG(FL_S, 0),
+		RX_FRAG(FL_E, 1),
+	};
+	struct mctp_test_route *rt;
+	struct mctp_test_dev *dev;
+	struct sk_buff *skb[5];
+	struct sk_buff *rx_skb;
+	struct socket *sock;
+	size_t data_len;
+	u8 compare[100];
+	u8 flat[100];
+	size_t total;
+	void *p;
+	int rc;
+
+	/* Arbitrary length */
+	data_len = 3;
+	total = data_len + sizeof(struct mctp_hdr);
+
+	__mctp_route_test_init(test, &dev, &rt, &sock, MCTP_NET_ANY);
+
+	/* Create a single skb initially with concatenated packets */
+	skb[0] = mctp_test_create_skb(&hdrs[0], 5 * total);
+	mctp_test_skb_set_dev(skb[0], dev);
+	memset(skb[0]->data, 0 * 0x11, skb[0]->len);
+	memcpy(skb[0]->data, &hdrs[0], sizeof(struct mctp_hdr));
+
+	/* Extract and populate packets */
+	for (int i = 1; i < 5; i++) {
+		skb[i] = skb_clone(skb[i - 1], GFP_ATOMIC);
+		KUNIT_ASSERT_TRUE(test, skb[i]);
+		p = skb_pull(skb[i], total);
+		KUNIT_ASSERT_TRUE(test, p);
+		skb_reset_network_header(skb[i]);
+		memcpy(skb[i]->data, &hdrs[i], sizeof(struct mctp_hdr));
+		memset(&skb[i]->data[sizeof(struct mctp_hdr)], i * 0x11, data_len);
+	}
+	for (int i = 0; i < 5; i++)
+		skb_trim(skb[i], total);
+
+	/* SOM packets have a type byte to match the socket */
+	skb[0]->data[4] = 0;
+	skb[3]->data[4] = 0;
+
+	skb_dump("pkt1 ", skb[0], false);
+	skb_dump("pkt2 ", skb[1], false);
+	skb_dump("pkt3 ", skb[2], false);
+	skb_dump("pkt4 ", skb[3], false);
+	skb_dump("pkt5 ", skb[4], false);
+
+	for (int i = 0; i < 5; i++) {
+		KUNIT_EXPECT_EQ(test, refcount_read(&skb[i]->users), 1);
+		/* Take a reference so we can check refcounts at the end */
+		skb_get(skb[i]);
+	}
+
+	/* Feed the fragments into MCTP core */
+	for (int i = 0; i < 5; i++) {
+		rc = mctp_route_input(&rt->rt, skb[i]);
+		KUNIT_EXPECT_EQ(test, rc, 0);
+	}
+
+	/* Receive first reassembled message */
+	rx_skb = skb_recv_datagram(sock->sk, MSG_DONTWAIT, &rc);
+	KUNIT_EXPECT_EQ(test, rc, 0);
+	KUNIT_EXPECT_EQ(test, rx_skb->len, 3 * data_len);
+	rc = skb_copy_bits(rx_skb, 0, flat, rx_skb->len);
+	for (int i = 0; i < rx_skb->len; i++)
+		compare[i] = (i / data_len) * 0x11;
+	/* Set type byte */
+	compare[0] = 0;
+
+	KUNIT_EXPECT_MEMEQ(test, flat, compare, rx_skb->len);
+	KUNIT_EXPECT_EQ(test, refcount_read(&rx_skb->users), 1);
+	kfree_skb(rx_skb);
+
+	/* Receive second reassembled message */
+	rx_skb = skb_recv_datagram(sock->sk, MSG_DONTWAIT, &rc);
+	KUNIT_EXPECT_EQ(test, rc, 0);
+	KUNIT_EXPECT_EQ(test, rx_skb->len, 2 * data_len);
+	rc = skb_copy_bits(rx_skb, 0, flat, rx_skb->len);
+	for (int i = 0; i < rx_skb->len; i++)
+		compare[i] = (i / data_len + 3) * 0x11;
+	/* Set type byte */
+	compare[0] = 0;
+
+	KUNIT_EXPECT_MEMEQ(test, flat, compare, rx_skb->len);
+	KUNIT_EXPECT_EQ(test, refcount_read(&rx_skb->users), 1);
+	kfree_skb(rx_skb);
+
+	/* Check input skb refcounts */
+	for (int i = 0; i < 5; i++) {
+		KUNIT_EXPECT_EQ(test, refcount_read(&skb[i]->users), 1);
+		kfree_skb(skb[i]);
+	}
+
+	__mctp_route_test_fini(test, dev, rt, sock);
+}
+
 #if IS_ENABLED(CONFIG_MCTP_FLOWS)
 
 static void mctp_test_flow_init(struct kunit *test,
@@ -1053,11 +1245,14 @@ static struct kunit_case mctp_test_cases[] = {
 			 mctp_route_input_sk_reasm_gen_params),
 	KUNIT_CASE_PARAM(mctp_test_route_input_sk_keys,
 			 mctp_route_input_sk_keys_gen_params),
+	KUNIT_CASE(mctp_test_route_input_sk_fail_single),
+	KUNIT_CASE(mctp_test_route_input_sk_fail_frag),
 	KUNIT_CASE(mctp_test_route_input_multiple_nets_bind),
 	KUNIT_CASE(mctp_test_route_input_multiple_nets_key),
 	KUNIT_CASE(mctp_test_packet_flow),
 	KUNIT_CASE(mctp_test_fragment_flow),
 	KUNIT_CASE(mctp_test_route_output_key_create),
+	KUNIT_CASE(mctp_test_route_input_cloned_frag),
 	{}
 };