Bluetooth: Add support for trust verification of management commands

Check the required trust level of each management command with the trust
level of the management socket. If it does not match up, then return the
newly introduced permission denied error.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/mgmt.h

@@ -44,6 +44,7 @@
 #define MGMT_STATUS_INVALID_INDEX	0x11
 #define MGMT_STATUS_RFKILLED		0x12
 #define MGMT_STATUS_ALREADY_PAIRED	0x13
+#define MGMT_STATUS_PERMISSION_DENIED	0x14
 
 struct mgmt_hdr {
 	__le16	opcode;

net/bluetooth/mgmt.c

@@ -6379,6 +6379,13 @@ int mgmt_control(struct hci_mgmt_chan *chan, struct sock *sk,
 
 	handler = &chan->handlers[opcode];
 
+	if (!hci_sock_test_flag(sk, HCI_SOCK_TRUSTED) &&
+	    !(handler->flags & HCI_MGMT_UNTRUSTED)) {
+		err = mgmt_cmd_status(sk, index, opcode,
+				      MGMT_STATUS_PERMISSION_DENIED);
+		goto done;
+	}
+
 	if (index != MGMT_INDEX_NONE) {
 		hdev = hci_dev_get(index);
 		if (!hdev) {