Bluetooth: Fix advertising duplicated flags

[ Upstream commit 6012b934 ]

Instances may have flags set as part of its data in which case the code
should not attempt to add it again otherwise it can cause duplication:

< HCI Command: LE Set Extended Advertising Data (0x08|0x0037) plen 35
        Handle: 0x00
        Operation: Complete extended advertising data (0x03)
        Fragment preference: Minimize fragmentation (0x01)
        Data length: 0x06
        Flags: 0x04
          BR/EDR Not Supported
        Flags: 0x06
          LE General Discoverable Mode
          BR/EDR Not Supported
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

net/bluetooth/hci_request.c

@@ -1093,6 +1093,14 @@ static u8 create_instance_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr)
 
 	instance_flags = get_adv_instance_flags(hdev, instance);
 
+	/* If instance already has the flags set skip adding it once
+	 * again.
+	 */
+	if (adv_instance && eir_get_data(adv_instance->adv_data,
+					 adv_instance->adv_data_len, EIR_FLAGS,
+					 NULL))
+		goto skip_flags;
+
 	/* The Add Advertising command allows userspace to set both the general
 	 * and limited discoverable flags.
 	 */
@@ -1125,6 +1133,7 @@ static u8 create_instance_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr)
 		}
 	}
 
+skip_flags:
 	if (adv_instance) {
 		memcpy(ptr, adv_instance->adv_data,
 		       adv_instance->adv_data_len);