Merge branch 'for-linus' of https://codeberg.org/linux-nfc/linux.git

7 files changed, 109 insertions, 24 deletions

diff --git a/net/nfc/digital_technology.c b/net/nfc/digital_technology.c
index ae63c5eb06fa..ae6487c10a25 100644
--- a/net/nfc/digital_technology.c
+++ b/net/nfc/digital_technology.c
@@ -778,6 +778,8 @@ static void digital_in_recv_sensf_res(struct nfc_digital_dev *ddev, void *arg,
 
 	sensf_res = (struct digital_sensf_res *)resp->data;
 
+	resp->len = min_t(unsigned int, resp->len, NFC_SENSF_RES_MAXSIZE);
+
 	memcpy(target.sensf_res, sensf_res, resp->len);
 	target.sensf_res_len = resp->len;
 
diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
index 291f26facbf3..ca89fe967d6a 100644
--- a/net/nfc/llcp_commands.c
+++ b/net/nfc/llcp_commands.c
@@ -193,7 +193,8 @@ int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
 			  const u8 *tlv_array, u16 tlv_array_len)
 {
 	const u8 *tlv = tlv_array;
-	u8 type, length, offset = 0;
+	u8 type, length;
+	u16 offset = 0;
 
 	pr_debug("TLV array length %d\n", tlv_array_len);
 
@@ -201,9 +202,15 @@ int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
 		return -ENODEV;
 
 	while (offset < tlv_array_len) {
+		if (offset + 2 > tlv_array_len)
+			return -EINVAL;
+
 		type = tlv[0];
 		length = tlv[1];
 
+		if (offset + 2 + length > tlv_array_len)
+			return -EINVAL;
+
 		pr_debug("type 0x%x length %d\n", type, length);
 
 		switch (type) {
@@ -243,7 +250,8 @@ int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
 				  const u8 *tlv_array, u16 tlv_array_len)
 {
 	const u8 *tlv = tlv_array;
-	u8 type, length, offset = 0;
+	u8 type, length;
+	u16 offset = 0;
 
 	pr_debug("TLV array length %d\n", tlv_array_len);
 
@@ -251,9 +259,15 @@ int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
 		return -ENOTCONN;
 
 	while (offset < tlv_array_len) {
+		if (offset + 2 > tlv_array_len)
+			return -EINVAL;
+
 		type = tlv[0];
 		length = tlv[1];
 
+		if (offset + 2 + length > tlv_array_len)
+			return -EINVAL;
+
 		pr_debug("type 0x%x length %d\n", type, length);
 
 		switch (type) {
diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c
index dc65c719f35f..aed5fe1afef0 100644
--- a/net/nfc/llcp_core.c
+++ b/net/nfc/llcp_core.c
@@ -1286,10 +1286,9 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 {
 	struct nfc_llcp_sock *llcp_sock;
 	u8 dsap, ssap, type, length, tid, sap;
-	const u8 *tlv;
-	u16 tlv_len, offset;
+	const u8 *tlv, *tlv_end;
 	const char *service_name;
-	size_t service_name_len;
+	int service_name_len;
 	struct nfc_llcp_sdp_tlv *sdp;
 	HLIST_HEAD(llc_sdres_list);
 	size_t sdres_tlvs_len;
@@ -1305,22 +1304,34 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 		return;
 	}
 
+	/*
+	 * Walk the SNL TLV list in the linear part of the skb only,
+	 * bounded by skb_tail_pointer(). Each TLV needs a two-byte
+	 * header (type, length) and its declared length must fit before
+	 * the end; this also keeps the walk safe for very short frames.
+	 */
 	tlv = &skb->data[LLCP_HEADER_SIZE];
-	tlv_len = skb->len - LLCP_HEADER_SIZE;
-	offset = 0;
+	tlv_end = skb_tail_pointer(skb);
 	sdres_tlvs_len = 0;
 
-	while (offset < tlv_len) {
+	while (tlv + 2 < tlv_end) {
 		type = tlv[0];
 		length = tlv[1];
 
+		if (tlv + 2 + length > tlv_end)
+			break;
+
 		switch (type) {
 		case LLCP_TLV_SDREQ:
+			if (length < 1)
+				break;
+
 			tid = tlv[2];
 			service_name = (char *) &tlv[3];
 			service_name_len = length - 1;
 
-			pr_debug("Looking for %.16s\n", service_name);
+			pr_debug("Looking for %.*s\n", service_name_len,
+				 service_name);
 
 			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
 			    !strncmp(service_name, "urn:nfc:sn:sdp",
@@ -1380,6 +1391,9 @@ add_snl:
 			break;
 
 		case LLCP_TLV_SDRES:
+			if (length != 2)
+				break;
+
 			mutex_lock(&local->sdreq_lock);
 
 			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
@@ -1408,7 +1422,6 @@ add_snl:
 			break;
 		}
 
-		offset += length + 2;
 		tlv += length + 2;
 	}
 
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
index feab29fc62f4..5558d8a4d48b 100644
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -319,14 +319,22 @@ static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
 	if (get_user(len, optlen))
 		return -EFAULT;
 
-	local = llcp_sock->local;
-	if (!local)
-		return -ENODEV;
+	if (len < 0)
+		return -EINVAL;
+
+	if (len < sizeof(u32))
+		return -EINVAL;
 
 	len = min_t(u32, len, sizeof(u32));
 
 	lock_sock(sk);
 
+	local = llcp_sock->local;
+	if (!local) {
+		release_sock(sk);
+		return -ENODEV;
+	}
+
 	switch (optname) {
 	case NFC_LLCP_RW:
 		rw = llcp_sock->rw > LLCP_MAX_RW ? local->rw : llcp_sock->rw;
diff --git a/net/nfc/nci/data.c b/net/nfc/nci/data.c
index 5f98c73db5af..4253edea5c8d 100644
--- a/net/nfc/nci/data.c
+++ b/net/nfc/nci/data.c
@@ -46,11 +46,11 @@ void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
 	timer_delete_sync(&ndev->data_timer);
 	clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
 
-	/* Mark the exchange as done before calling the callback.
-	 * The callback (e.g. rawsock_data_exchange_complete) may
-	 * want to immediately queue another data exchange.
-	 */
-	clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
+	/* Claim completion atomically -- both close and rx_work may race here */
+	if (!test_and_clear_bit(NCI_DATA_EXCHANGE, &ndev->flags)) {
+		kfree_skb(skb);
+		return;
+	}
 
 	if (cb) {
 		/* forward skb to nfc core */
diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c
index c96512bb8653..87f76a29f0ec 100644
--- a/net/nfc/nci/ntf.c
+++ b/net/nfc/nci/ntf.c
@@ -525,15 +525,19 @@ static int nci_rf_discover_ntf_packet(struct nci_dev *ndev,
 
 static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
 						 struct nci_rf_intf_activated_ntf *ntf,
-						 const __u8 *data)
+						 const __u8 *data, __u8 data_len)
 {
 	struct activation_params_nfca_poll_iso_dep *nfca_poll;
 	struct activation_params_nfcb_poll_iso_dep *nfcb_poll;
 
 	switch (ntf->activation_rf_tech_and_mode) {
 	case NCI_NFC_A_PASSIVE_POLL_MODE:
+		if (data_len < 1)
+			return NCI_STATUS_RF_PROTOCOL_ERROR;
 		nfca_poll = &ntf->activation_params.nfca_poll_iso_dep;
 		nfca_poll->rats_res_len = min_t(__u8, *data++, NFC_ATS_MAXSIZE);
+		data_len--;
+		nfca_poll->rats_res_len = min_t(__u8, nfca_poll->rats_res_len, data_len);
 		pr_debug("rats_res_len %d\n", nfca_poll->rats_res_len);
 		if (nfca_poll->rats_res_len > 0) {
 			memcpy(nfca_poll->rats_res,
@@ -542,8 +546,12 @@ static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
 		break;
 
 	case NCI_NFC_B_PASSIVE_POLL_MODE:
+		if (data_len < 1)
+			return NCI_STATUS_RF_PROTOCOL_ERROR;
 		nfcb_poll = &ntf->activation_params.nfcb_poll_iso_dep;
 		nfcb_poll->attrib_res_len = min_t(__u8, *data++, 50);
+		data_len--;
+		nfcb_poll->attrib_res_len = min_t(__u8, nfcb_poll->attrib_res_len, data_len);
 		pr_debug("attrib_res_len %d\n", nfcb_poll->attrib_res_len);
 		if (nfcb_poll->attrib_res_len > 0) {
 			memcpy(nfcb_poll->attrib_res,
@@ -562,7 +570,7 @@ static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
 
 static int nci_extract_activation_params_nfc_dep(struct nci_dev *ndev,
 						 struct nci_rf_intf_activated_ntf *ntf,
-						 const __u8 *data)
+						 const __u8 *data, __u8 data_len)
 {
 	struct activation_params_poll_nfc_dep *poll;
 	struct activation_params_listen_nfc_dep *listen;
@@ -570,9 +578,13 @@ static int nci_extract_activation_params_nfc_dep(struct nci_dev *ndev,
 	switch (ntf->activation_rf_tech_and_mode) {
 	case NCI_NFC_A_PASSIVE_POLL_MODE:
 	case NCI_NFC_F_PASSIVE_POLL_MODE:
+		if (data_len < 1)
+			return NCI_STATUS_RF_PROTOCOL_ERROR;
 		poll = &ntf->activation_params.poll_nfc_dep;
 		poll->atr_res_len = min_t(__u8, *data++,
 					  NFC_ATR_RES_MAXSIZE - 2);
+		data_len--;
+		poll->atr_res_len = min_t(__u8, poll->atr_res_len, data_len);
 		pr_debug("atr_res_len %d\n", poll->atr_res_len);
 		if (poll->atr_res_len > 0)
 			memcpy(poll->atr_res, data, poll->atr_res_len);
@@ -580,9 +592,13 @@ static int nci_extract_activation_params_nfc_dep(struct nci_dev *ndev,
 
 	case NCI_NFC_A_PASSIVE_LISTEN_MODE:
 	case NCI_NFC_F_PASSIVE_LISTEN_MODE:
+		if (data_len < 1)
+			return NCI_STATUS_RF_PROTOCOL_ERROR;
 		listen = &ntf->activation_params.listen_nfc_dep;
 		listen->atr_req_len = min_t(__u8, *data++,
 					    NFC_ATR_REQ_MAXSIZE - 2);
+		data_len--;
+		listen->atr_req_len = min_t(__u8, listen->atr_req_len, data_len);
 		pr_debug("atr_req_len %d\n", listen->atr_req_len);
 		if (listen->atr_req_len > 0)
 			memcpy(listen->atr_req, data, listen->atr_req_len);
@@ -603,6 +619,12 @@ static void nci_target_auto_activated(struct nci_dev *ndev,
 	struct nfc_target *target;
 	int rc;
 
+	/* This is a new target, check if we've enough room */
+	if (ndev->n_targets == NCI_MAX_DISCOVERED_TARGETS) {
+		pr_debug("not enough room, ignoring new target...\n");
+		return;
+	}
+
 	target = &ndev->targets[ndev->n_targets];
 
 	rc = nci_add_new_protocol(ndev, target, ntf->rf_protocol,
@@ -806,12 +828,14 @@ static int nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,
 		switch (ntf.rf_interface) {
 		case NCI_RF_INTERFACE_ISO_DEP:
 			err = nci_extract_activation_params_iso_dep(ndev,
-								    &ntf, data);
+								    &ntf, data,
+								    ntf.activation_params_len);
 			break;
 
 		case NCI_RF_INTERFACE_NFC_DEP:
 			err = nci_extract_activation_params_nfc_dep(ndev,
-								    &ntf, data);
+								    &ntf, data,
+								    ntf.activation_params_len);
 			break;
 
 		case NCI_RF_INTERFACE_FRAME:
diff --git a/net/nfc/nci/rsp.c b/net/nfc/nci/rsp.c
index 9eeb862825c5..6b2fa6bdbd14 100644
--- a/net/nfc/nci/rsp.c
+++ b/net/nfc/nci/rsp.c
@@ -50,11 +50,25 @@ static u8 nci_core_init_rsp_packet_v1(struct nci_dev *ndev,
 	const struct nci_core_init_rsp_1 *rsp_1 = (void *)skb->data;
 	const struct nci_core_init_rsp_2 *rsp_2;
 
+	if (skb->len < sizeof(*rsp_1))
+		return NCI_STATUS_SYNTAX_ERROR;
+
 	pr_debug("status 0x%x\n", rsp_1->status);
 
 	if (rsp_1->status != NCI_STATUS_OK)
 		return rsp_1->status;
 
+	/*
+	 * supported_rf_interfaces[] and the trailing nci_core_init_rsp_2 are
+	 * addressed using the on-wire (unclamped) interface count, so the
+	 * response must be long enough for both before any of it is parsed or
+	 * stored into @ndev - otherwise a truncated response would leave
+	 * ndev->num_supported_rf_interfaces holding the unclamped count.
+	 */
+	if (skb->len < sizeof(*rsp_1) +
+	    rsp_1->num_supported_rf_interfaces + sizeof(*rsp_2))
+		return NCI_STATUS_SYNTAX_ERROR;
+
 	ndev->nfcc_features = __le32_to_cpu(rsp_1->nfcc_features);
 	ndev->num_supported_rf_interfaces = rsp_1->num_supported_rf_interfaces;
 
@@ -88,9 +102,13 @@ static u8 nci_core_init_rsp_packet_v2(struct nci_dev *ndev,
 {
 	const struct nci_core_init_rsp_nci_ver2 *rsp = (void *)skb->data;
 	const u8 *supported_rf_interface = rsp->supported_rf_interfaces;
+	const u8 *end = skb->data + skb->len;
 	u8 rf_interface_idx = 0;
 	u8 rf_extension_cnt = 0;
 
+	if (skb->len < sizeof(*rsp))
+		return NCI_STATUS_SYNTAX_ERROR;
+
 	pr_debug("status %x\n", rsp->status);
 
 	if (rsp->status != NCI_STATUS_OK)
@@ -104,10 +122,16 @@ static u8 nci_core_init_rsp_packet_v2(struct nci_dev *ndev,
 		    NCI_MAX_SUPPORTED_RF_INTERFACES);
 
 	while (rf_interface_idx < ndev->num_supported_rf_interfaces) {
-		ndev->supported_rf_interfaces[rf_interface_idx++] = *supported_rf_interface++;
+		/* one interface byte + one extension-count byte must be present */
+		if (end - supported_rf_interface < 2)
+			return NCI_STATUS_SYNTAX_ERROR;
+		ndev->supported_rf_interfaces[rf_interface_idx++] =
+			*supported_rf_interface++;
 
-		/* skip rf extension parameters */
+		/* skip rf extension parameters, bounded by the packet */
 		rf_extension_cnt = *supported_rf_interface++;
+		if (rf_extension_cnt > end - supported_rf_interface)
+			return NCI_STATUS_SYNTAX_ERROR;
 		supported_rf_interface += rf_extension_cnt;
 	}