BLE advertising broken on 6.18.34+rpt: MGMT Add Extended Advertising Data returns Invalid Parameters

[DeLsonJabberwo]

Describe the bug

On kernel 6.18.34+rpt-rpi-2712 (Pi 5, BCM43455, BlueZ 5.82), registering a BLE advertisement through bluetoothd fails: the Add Extended Advertising Data management command (0x0055) is rejected with Invalid Parameters (0x0d) for a payload that is well within limits — 18 bytes of advertising data (one complete 128-bit service UUID) plus a 17-byte scan response (complete local name), against a reported 28/31 bytes available. bluetoothd logs Failed to add advertisement: Invalid Parameters (0x0d) and nothing goes on air. The identical userspace (BlueZ 5.82, same application) works on 6.12.47+rpt-rpi-2712.

Two additional observations pointing at length-accounting in the new mgmt path:

• The legacy Add Advertising (0x003e) path still works on 6.18.34 — btmgmt add-adv with the same UUID payload advertises fine.
• On that legacy path, requesting local-name-in-scan-response truncates a 15-character name to 10 characters (Name (short)) despite ample space in the 31-byte scan response; supplying the complete-name AD structure as explicit scan-response data works.

Steps to reproduce the behaviour

1. Register any GATT peripheral with an advertisement via the BlueZ D-Bus LEAdvertisingManager1 API (one 128-bit service UUID + local name) on 6.18.34+rpt.
2. Observe the mgmt failure in btmon and Failed to add advertisement from bluetoothd.
3. Same registration succeeds on 6.12.47+rpt.

Device (s)

Raspberry Pi 5

System

https://pastebin.com/Y3gBAEbr

Logs

Trace 1: the failing registration

= Note: Linux version 6.18.34+rpt-rpi-2712 (aarch64)
= Note: Bluetooth subsystem version 2.22
= Index Info: 88:A2:9E:98:19:92 (Cypress Semiconductor)

bluetoothd: @ MGMT Command: Add Extended Advertising Parameters (0x0054) plen 18
        Instance: 1
        Flags: 0x00010003
          Switch into Connectable mode
          Advertise as Discoverable
          Contain Scan Response Data
        Duration: 0
        Timeout: 0
        Min advertising interval: 0.000 msec (0x0000)
        Max advertising interval: 0.000 msec (0x0000)
        TX power: 0 dbm (0x00)
@ MGMT Event: Command Complete (0x0001) plen 7
      Add Extended Advertising Parameters (0x0054) plen 4
        Status: Success (0x00)
        Instance: 1
        TX power: 127 dbm (0x7f)
        Available adv data len: 28
        Available scan rsp data len: 31
bluetoothd: @ MGMT Command: Add Extended Advertising Data (0x0055) plen 46
        Instance: 1
        Advertising data length: 18
        128-bit Service UUIDs (complete): 1 entry
          Vendor specific
        Scan response length: 17
        Name (complete): ************* [REDACTED]
@ MGMT Event: Command Status (0x0002) plen 3
      Add Extended Advertising Data (0x0055)
        Status: Invalid Parameters (0x0d)
bluetoothd: = src/advertising.c:add_client_complete() Failed to add advertisement: Invalid Parameters (0x0d)

Trace 2: legacy op suceeding

btmgmt: @ MGMT Command: Add Advertising (0x003e) plen 29
        Instance: 2
        Flags: 0x00000043
          Switch into Connectable mode
          Advertise as Discoverable
          Add Local Name in Scan Response
        Duration: 0
        Timeout: 0
        Advertising data length: 18
        128-bit Service UUIDs (complete): 1 entry
          Vendor specific
        Scan response length: 0
@ MGMT Event: Advertising Added (0x0023) plen 1
        Instance: 2
@ MGMT Event: Command Complete (0x0001) plen 4
      Add Advertising (0x003e) plen 1
        Status: Success (0x00)
        Instance: 2
< HCI Command: LE Set Advertising Data (0x08|0x0008) plen 32
        Length: 21
        Flags: 0x02
          LE General Discoverable Mode
        128-bit Service UUIDs (complete): 1 entry
          Vendor specific
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Advertising Data (0x08|0x0008) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Scan Response Data (0x08|0x0009) plen 32
        Length: 12
        Name (short): ********* [REDACTED]
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Scan Response Data (0x08|0x0009) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Advertise Enable (0x08|0x000a) plen 1
        Advertising: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Advertise Enable (0x08|0x000a) ncmd 1
        Status: Success (0x00)

Additional context

No response