1 files changed, 175 insertions, 114 deletions

diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c
index 81cd3416c7d4..beeb3b4d28ca 100644
--- a/net/nfc/llcp_core.c
+++ b/net/nfc/llcp_core.c
@@ -1,20 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2011  Intel Corporation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the
- * Free Software Foundation, Inc.,
- * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * Copyright (C) 2014 Marvell International Ltd.
  */
 
 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
@@ -29,7 +16,9 @@
 
 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
 
-static struct list_head llcp_devices;
+static LIST_HEAD(llcp_devices);
+/* Protects llcp_devices list */
+static DEFINE_SPINLOCK(llcp_devices_lock);
 
 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
 
@@ -58,8 +47,6 @@ static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
 	struct nfc_llcp_local *local = sock->local;
 	struct sk_buff *s, *tmp;
 
-	pr_debug("%p\n", &sock->sk);
-
 	skb_queue_purge(&sock->tx_queue);
 	skb_queue_purge(&sock->tx_pending_queue);
 
@@ -156,8 +143,15 @@ static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,
 	write_unlock(&local->raw_sockets.lock);
 }
 
-struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
+static struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
 {
+	/* Since using nfc_llcp_local may result in usage of nfc_dev, whenever
+	 * we hold a reference to local, we also need to hold a reference to
+	 * the device to avoid UAF.
+	 */
+	if (!nfc_get_device(local->dev->idx))
+		return NULL;
+
 	kref_get(&local->ref);
 
 	return local;
@@ -166,13 +160,14 @@ struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
 static void local_cleanup(struct nfc_llcp_local *local)
 {
 	nfc_llcp_socket_release(local, false, ENXIO);
-	del_timer_sync(&local->link_timer);
+	timer_delete_sync(&local->link_timer);
 	skb_queue_purge(&local->tx_queue);
 	cancel_work_sync(&local->tx_work);
 	cancel_work_sync(&local->rx_work);
 	cancel_work_sync(&local->timeout_work);
 	kfree_skb(local->rx_pending);
-	del_timer_sync(&local->sdreq_timer);
+	local->rx_pending = NULL;
+	timer_delete_sync(&local->sdreq_timer);
 	cancel_work_sync(&local->sdreq_timeout_work);
 	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
 }
@@ -183,17 +178,24 @@ static void local_release(struct kref *ref)
 
 	local = container_of(ref, struct nfc_llcp_local, ref);
 
-	list_del(&local->list);
 	local_cleanup(local);
 	kfree(local);
 }
 
 int nfc_llcp_local_put(struct nfc_llcp_local *local)
 {
+	struct nfc_dev *dev;
+	int ret;
+
 	if (local == NULL)
 		return 0;
 
-	return kref_put(&local->ref, local_release);
+	dev = local->dev;
+
+	ret = kref_put(&local->ref, local_release);
+	nfc_put_device(dev);
+
+	return ret;
 }
 
 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
@@ -216,17 +218,13 @@ static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
 
 		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
 			llcp_sock = tmp_sock;
+			sock_hold(&llcp_sock->sk);
 			break;
 		}
 	}
 
 	read_unlock(&local->sockets.lock);
 
-	if (llcp_sock == NULL)
-		return NULL;
-
-	sock_hold(&llcp_sock->sk);
-
 	return llcp_sock;
 }
 
@@ -243,9 +241,10 @@ static void nfc_llcp_timeout_work(struct work_struct *work)
 	nfc_dep_link_down(local->dev);
 }
 
-static void nfc_llcp_symm_timer(unsigned long data)
+static void nfc_llcp_symm_timer(struct timer_list *t)
 {
-	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
+	struct nfc_llcp_local *local = timer_container_of(local, t,
+							  link_timer);
 
 	pr_err("SYMM timeout\n");
 
@@ -286,22 +285,44 @@ static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
 }
 
-static void nfc_llcp_sdreq_timer(unsigned long data)
+static void nfc_llcp_sdreq_timer(struct timer_list *t)
 {
-	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
+	struct nfc_llcp_local *local = timer_container_of(local, t,
+							  sdreq_timer);
 
 	schedule_work(&local->sdreq_timeout_work);
 }
 
 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
 {
-	struct nfc_llcp_local *local, *n;
+	struct nfc_llcp_local *local;
+	struct nfc_llcp_local *res = NULL;
 
-	list_for_each_entry_safe(local, n, &llcp_devices, list)
-		if (local->dev == dev)
+	spin_lock(&llcp_devices_lock);
+	list_for_each_entry(local, &llcp_devices, list)
+		if (local->dev == dev) {
+			res = nfc_llcp_local_get(local);
+			break;
+		}
+	spin_unlock(&llcp_devices_lock);
+
+	return res;
+}
+
+static struct nfc_llcp_local *nfc_llcp_remove_local(struct nfc_dev *dev)
+{
+	struct nfc_llcp_local *local, *tmp;
+
+	spin_lock(&llcp_devices_lock);
+	list_for_each_entry_safe(local, tmp, &llcp_devices, list)
+		if (local->dev == dev) {
+			list_del(&local->list);
+			spin_unlock(&llcp_devices_lock);
 			return local;
+		}
+	spin_unlock(&llcp_devices_lock);
 
-	pr_debug("No device found\n");
+	pr_warn("Shutting down device not found\n");
 
 	return NULL;
 }
@@ -314,7 +335,7 @@ static char *wks[] = {
 	"urn:nfc:sn:snep",
 };
 
-static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
+static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
 {
 	int sap, num_wks;
 
@@ -338,7 +359,8 @@ static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
 
 static
 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
-					    u8 *sn, size_t sn_len)
+					    const u8 *sn, size_t sn_len,
+					    bool needref)
 {
 	struct sock *sk;
 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
@@ -374,6 +396,8 @@ struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
 
 		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
 			llcp_sock = tmp_sock;
+			if (needref)
+				sock_hold(&llcp_sock->sk);
 			break;
 		}
 	}
@@ -398,7 +422,7 @@ u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
 			pr_debug("WKS %d\n", ssap);
 
 			/* This is a WKS, let's check if it's free */
-			if (local->local_wks & BIT(ssap)) {
+			if (test_bit(ssap, &local->local_wks)) {
 				mutex_unlock(&local->sdp_lock);
 
 				return LLCP_SAP_MAX;
@@ -415,7 +439,8 @@ u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
 		 * to this service name.
 		 */
 		if (nfc_llcp_sock_from_sn(local, sock->service_name,
-					  sock->service_name_len) != NULL) {
+					  sock->service_name_len,
+					  false) != NULL) {
 			mutex_unlock(&local->sdp_lock);
 
 			return LLCP_SAP_MAX;
@@ -533,10 +558,10 @@ static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
 
 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
 {
-	u8 *gb_cur, *version_tlv, version, version_length;
-	u8 *lto_tlv, lto_length;
-	u8 *wks_tlv, wks_length;
-	u8 *miux_tlv, miux_length;
+	u8 *gb_cur, version, version_length;
+	u8 lto_length, wks_length, miux_length;
+	const u8 *version_tlv = NULL, *lto_tlv = NULL,
+	   *wks_tlv = NULL, *miux_tlv = NULL;
 	__be16 wks = cpu_to_be16(local->local_wks);
 	u8 gb_len = 0;
 	int ret = 0;
@@ -544,17 +569,33 @@ static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
 	version = LLCP_VERSION_11;
 	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
 					 1, &version_length);
+	if (!version_tlv) {
+		ret = -ENOMEM;
+		goto out;
+	}
 	gb_len += version_length;
 
 	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
+	if (!lto_tlv) {
+		ret = -ENOMEM;
+		goto out;
+	}
 	gb_len += lto_length;
 
 	pr_debug("Local wks 0x%lx\n", local->local_wks);
 	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
+	if (!wks_tlv) {
+		ret = -ENOMEM;
+		goto out;
+	}
 	gb_len += wks_length;
 
 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
 				      &miux_length);
+	if (!miux_tlv) {
+		ret = -ENOMEM;
+		goto out;
+	}
 	gb_len += miux_length;
 
 	gb_len += ARRAY_SIZE(llcp_magic);
@@ -606,19 +647,24 @@ u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
 
 	*general_bytes_len = local->gb_len;
 
+	nfc_llcp_local_put(local);
+
 	return local->gb;
 }
 
-int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
+int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
 {
-	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
+	struct nfc_llcp_local *local;
+	int err;
+
+	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
+		return -EINVAL;
 
+	local = nfc_llcp_find_local(dev);
 	if (local == NULL) {
 		pr_err("No LLCP device\n");
 		return -ENODEV;
 	}
-	if (gb_len < 3)
-		return -EINVAL;
 
 	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
 	memcpy(local->remote_gb, gb, gb_len);
@@ -626,35 +672,39 @@ int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
 
 	if (memcmp(local->remote_gb, llcp_magic, 3)) {
 		pr_err("MAC does not support LLCP\n");
-		return -EINVAL;
+		err = -EINVAL;
+		goto out;
 	}
 
-	return nfc_llcp_parse_gb_tlv(local,
+	err = nfc_llcp_parse_gb_tlv(local,
 				     &local->remote_gb[3],
 				     local->remote_gb_len - 3);
+out:
+	nfc_llcp_local_put(local);
+	return err;
 }
 
-static u8 nfc_llcp_dsap(struct sk_buff *pdu)
+static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
 {
 	return (pdu->data[0] & 0xfc) >> 2;
 }
 
-static u8 nfc_llcp_ptype(struct sk_buff *pdu)
+static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
 {
 	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
 }
 
-static u8 nfc_llcp_ssap(struct sk_buff *pdu)
+static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
 {
 	return pdu->data[1] & 0x3f;
 }
 
-static u8 nfc_llcp_ns(struct sk_buff *pdu)
+static u8 nfc_llcp_ns(const struct sk_buff *pdu)
 {
 	return pdu->data[2] >> 4;
 }
 
-static u8 nfc_llcp_nr(struct sk_buff *pdu)
+static u8 nfc_llcp_nr(const struct sk_buff *pdu)
 {
 	return pdu->data[2] & 0xf;
 }
@@ -680,16 +730,17 @@ void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
 			continue;
 
 		if (skb_copy == NULL) {
-			skb_copy = __pskb_copy(skb, NFC_LLCP_RAW_HEADER_SIZE,
-					       GFP_ATOMIC);
+			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
+						      GFP_ATOMIC, true);
 
 			if (skb_copy == NULL)
 				continue;
 
-			data = skb_push(skb_copy, NFC_LLCP_RAW_HEADER_SIZE);
+			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
 
 			data[0] = local->dev ? local->dev->idx : 0xFF;
-			data[1] = direction;
+			data[1] = direction & 0x01;
+			data[1] |= (RAW_PAYLOAD_LLCP << 1);
 		}
 
 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
@@ -730,16 +781,8 @@ static void nfc_llcp_tx_work(struct work_struct *work)
 			int ret;
 
 			pr_debug("Sending pending skb\n");
-			print_hex_dump(KERN_DEBUG, "LLCP Tx: ",
-				       DUMP_PREFIX_OFFSET, 16, 1,
-				       skb->data, skb->len, true);
-
-			if (ptype == LLCP_PDU_DISC && sk != NULL &&
-			    sk->sk_state == LLCP_DISCONNECTING) {
-				nfc_llcp_sock_unlink(&local->sockets, sk);
-				sock_orphan(sk);
-				sock_put(sk);
-			}
+			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
+					     16, 1, skb->data, skb->len, true);
 
 			if (ptype == LLCP_PDU_I)
 				copy_skb = skb_copy(skb, GFP_ATOMIC);
@@ -747,7 +790,7 @@ static void nfc_llcp_tx_work(struct work_struct *work)
 			__net_timestamp(skb);
 
 			nfc_llcp_send_to_raw_sock(local, skb,
-						  NFC_LLCP_DIRECTION_TX);
+						  NFC_DIRECTION_TX);
 
 			ret = nfc_data_exchange(local->dev, local->target_idx,
 						skb, nfc_llcp_recv, local);
@@ -796,23 +839,15 @@ out:
 }
 
 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
-						  u8 *sn, size_t sn_len)
+						  const u8 *sn, size_t sn_len)
 {
-	struct nfc_llcp_sock *llcp_sock;
-
-	llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
-
-	if (llcp_sock == NULL)
-		return NULL;
-
-	sock_hold(&llcp_sock->sk);
-
-	return llcp_sock;
+	return nfc_llcp_sock_from_sn(local, sn, sn_len, true);
 }
 
-static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
+static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
 {
-	u8 *tlv = &skb->data[2], type, length;
+	u8 type, length;
+	const u8 *tlv = &skb->data[2];
 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
 
 	while (offset < tlv_array_len) {
@@ -870,7 +905,7 @@ static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
 }
 
 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
-				  struct sk_buff *skb)
+				  const struct sk_buff *skb)
 {
 	struct sock *new_sk, *parent;
 	struct nfc_llcp_sock *sock, *new_sock;
@@ -888,7 +923,7 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 			goto fail;
 		}
 	} else {
-		u8 *sn;
+		const u8 *sn;
 		size_t sn_len;
 
 		sn = nfc_llcp_connect_sn(skb, &sn_len);
@@ -932,7 +967,7 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 		sock->ssap = ssap;
 	}
 
-	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC);
+	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
 	if (new_sk == NULL) {
 		reason = LLCP_DM_REJ;
 		release_sock(&sock->sk);
@@ -941,11 +976,19 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 	}
 
 	new_sock = nfc_llcp_sock(new_sk);
-	new_sock->dev = local->dev;
+
 	new_sock->local = nfc_llcp_local_get(local);
+	if (!new_sock->local) {
+		reason = LLCP_DM_REJ;
+		sock_put(&new_sock->sk);
+		release_sock(&sock->sk);
+		sock_put(&sock->sk);
+		goto fail;
+	}
+
+	new_sock->dev = local->dev;
 	new_sock->rw = sock->rw;
 	new_sock->miux = sock->miux;
-	new_sock->remote_miu = local->remote_miu;
 	new_sock->nfc_protocol = sock->nfc_protocol;
 	new_sock->dsap = ssap;
 	new_sock->target_idx = local->target_idx;
@@ -977,7 +1020,7 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 	new_sk->sk_state = LLCP_CONNECTED;
 
 	/* Wake the listening processes */
-	parent->sk_data_ready(parent, 0);
+	parent->sk_data_ready(parent);
 
 	/* Send CC */
 	nfc_llcp_send_cc(new_sock);
@@ -1108,7 +1151,7 @@ static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
 }
 
 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
-			       struct sk_buff *skb)
+			       const struct sk_buff *skb)
 {
 	struct nfc_llcp_sock *llcp_sock;
 	struct sock *sk;
@@ -1151,7 +1194,8 @@ static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
 	nfc_llcp_sock_put(llcp_sock);
 }
 
-static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)
+static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
+			     const struct sk_buff *skb)
 {
 	struct nfc_llcp_sock *llcp_sock;
 	struct sock *sk;
@@ -1184,7 +1228,8 @@ static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)
 	nfc_llcp_sock_put(llcp_sock);
 }
 
-static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
+static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
+			     const struct sk_buff *skb)
 {
 	struct nfc_llcp_sock *llcp_sock;
 	struct sock *sk;
@@ -1222,12 +1267,13 @@ static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
 }
 
 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
-			      struct sk_buff *skb)
+			      const struct sk_buff *skb)
 {
 	struct nfc_llcp_sock *llcp_sock;
-	u8 dsap, ssap, *tlv, type, length, tid, sap;
+	u8 dsap, ssap, type, length, tid, sap;
+	const u8 *tlv;
 	u16 tlv_len, offset;
-	char *service_name;
+	const char *service_name;
 	size_t service_name_len;
 	struct nfc_llcp_sdp_tlv *sdp;
 	HLIST_HEAD(llc_sdres_list);
@@ -1269,7 +1315,8 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 			}
 
 			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
-							  service_name_len);
+							  service_name_len,
+							  true);
 			if (!llcp_sock) {
 				sap = 0;
 				goto add_snl;
@@ -1289,6 +1336,7 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 
 				if (sap == LLCP_SAP_MAX) {
 					sap = 0;
+					nfc_llcp_sock_put(llcp_sock);
 					goto add_snl;
 				}
 
@@ -1306,6 +1354,7 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 
 			pr_debug("%p %d\n", llcp_sock, sap);
 
+			nfc_llcp_sock_put(llcp_sock);
 add_snl:
 			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
 			if (sdp == NULL)
@@ -1390,7 +1439,7 @@ static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
 			return;
 		}
 
-		memcpy(skb_put(new_skb, pdu_len), skb->data, pdu_len);
+		skb_put_data(new_skb, skb->data, pdu_len);
 
 		nfc_llcp_rx_skb(local, new_skb);
 
@@ -1411,8 +1460,8 @@ static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
 	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
 
 	if (ptype != LLCP_PDU_SYMM)
-		print_hex_dump(KERN_DEBUG, "LLCP Rx: ", DUMP_PREFIX_OFFSET,
-			       16, 1, skb->data, skb->len, true);
+		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
+				     skb->data, skb->len, true);
 
 	switch (ptype) {
 	case LLCP_PDU_SYMM:
@@ -1477,7 +1526,7 @@ static void nfc_llcp_rx_work(struct work_struct *work)
 
 	__net_timestamp(skb);
 
-	nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_RX);
+	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
 
 	nfc_llcp_rx_skb(local, skb);
 
@@ -1489,7 +1538,7 @@ static void nfc_llcp_rx_work(struct work_struct *work)
 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
 {
 	local->rx_pending = skb;
-	del_timer(&local->link_timer);
+	timer_delete(&local->link_timer);
 	schedule_work(&local->rx_work);
 }
 
@@ -1497,9 +1546,8 @@ void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
 {
 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
 
-	pr_debug("Received an LLCP PDU\n");
 	if (err < 0) {
-		pr_err("err %d\n", err);
+		pr_err("LLCP PDU receive err %d\n", err);
 		return;
 	}
 
@@ -1511,11 +1559,15 @@ int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
 	struct nfc_llcp_local *local;
 
 	local = nfc_llcp_find_local(dev);
-	if (local == NULL)
+	if (local == NULL) {
+		kfree_skb(skb);
 		return -ENODEV;
+	}
 
 	__nfc_llcp_recv(local, skb);
 
+	nfc_llcp_local_put(local);
+
 	return 0;
 }
 
@@ -1532,6 +1584,8 @@ void nfc_llcp_mac_is_down(struct nfc_dev *dev)
 
 	/* Close and purge all existing sockets */
 	nfc_llcp_socket_release(local, true, 0);
+
+	nfc_llcp_local_put(local);
 }
 
 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
@@ -1557,6 +1611,8 @@ void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
 		mod_timer(&local->link_timer,
 			  jiffies + msecs_to_jiffies(local->remote_lto));
 	}
+
+	nfc_llcp_local_put(local);
 }
 
 int nfc_llcp_register_device(struct nfc_dev *ndev)
@@ -1567,13 +1623,20 @@ int nfc_llcp_register_device(struct nfc_dev *ndev)
 	if (local == NULL)
 		return -ENOMEM;
 
-	local->dev = ndev;
+	/* As we are going to initialize local's refcount, we need to get the
+	 * nfc_dev to avoid UAF, otherwise there is no point in continuing.
+	 * See nfc_llcp_local_get().
+	 */
+	local->dev = nfc_get_device(ndev->idx);
+	if (!local->dev) {
+		kfree(local);
+		return -ENODEV;
+	}
+
 	INIT_LIST_HEAD(&local->list);
 	kref_init(&local->ref);
 	mutex_init(&local->sdp_lock);
-	init_timer(&local->link_timer);
-	local->link_timer.data = (unsigned long) local;
-	local->link_timer.function = nfc_llcp_symm_timer;
+	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
 
 	skb_queue_head_init(&local->tx_queue);
 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
@@ -1599,19 +1662,19 @@ int nfc_llcp_register_device(struct nfc_dev *ndev)
 
 	mutex_init(&local->sdreq_lock);
 	INIT_HLIST_HEAD(&local->pending_sdreqs);
-	init_timer(&local->sdreq_timer);
-	local->sdreq_timer.data = (unsigned long) local;
-	local->sdreq_timer.function = nfc_llcp_sdreq_timer;
+	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
 
+	spin_lock(&llcp_devices_lock);
 	list_add(&local->list, &llcp_devices);
+	spin_unlock(&llcp_devices_lock);
 
 	return 0;
 }
 
 void nfc_llcp_unregister_device(struct nfc_dev *dev)
 {
-	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
+	struct nfc_llcp_local *local = nfc_llcp_remove_local(dev);
 
 	if (local == NULL) {
 		pr_debug("No such device\n");
@@ -1625,8 +1688,6 @@ void nfc_llcp_unregister_device(struct nfc_dev *dev)
 
 int __init nfc_llcp_init(void)
 {
-	INIT_LIST_HEAD(&llcp_devices);
-
 	return nfc_llcp_sock_init();
 }