Public bug reported:
## Package / target
- Package: `linux` (Ubuntu 26.04)
- Regression: **works on `7.0.0-27.27`, broken on `7.0.0-28.28`**
## Summary
Since `linux-image-7.0.0-28-generic`, registering any BLE LE advertisement
through BlueZ (the D-Bus `org.bluez.LEAdvertisingManager1` API) fails. The
kernel rejects the MGMT `Add Extended Advertising Data` (0x0055) command with
`Invalid Parameters (0x0d)`, even for a minimal, valid 3-byte advertisement
that is well within the length limits the controller just reported. Any
application that advertises as a BLE peripheral via BlueZ is broken; only the
legacy MGMT `Add Advertising` (0x003e) path still works.
## Impact
All BlueZ D-Bus peripheral advertising is broken on this kernel — e.g. GATT
peripherals, pairing beacons, custom LE services. bluetoothd always uses the
extended MGMT path when the kernel exposes it, and there is no configuration
to force the legacy path, so affected apps have no userspace workaround.
## Reproduce
On an affected machine:
# terminal 1
sudo btmon
# terminal 2 — legacy MGMT path: SUCCEEDS
sudo btmgmt add-adv -c 1
# bluetoothd's D-Bus/extended path: FAILS
bluetoothctl advertise peripheral
# -> Failed to register advertisement: org.bluez.Error.Failed
btmon, failing (extended) path:
@ MGMT Command: Add Extended Advertising Parameters (0x0054) plen 18
Instance: 1
Flags: 0x00000001 (Switch into Connectable mode)
@ MGMT Event: Command Complete (0x0001)
Add Extended Advertising Parameters (0x0054)
Status: Success (0x00)
Available adv data len: 31
Available scan rsp data len: 31
@ MGMT Command: Add Extended Advertising Data (0x0055) plen 14
Instance: 1
Advertising data length: 3
Flags: 0x06 (LE General Discoverable Mode, BR/EDR Not Supported)
Scan response length: 0
@ MGMT Event: Command Status (0x0002)
Add Extended Advertising Data (0x0055)
Status: Invalid Parameters (0x0d)
bluetoothd: src/advertising.c:add_client_complete() Failed to add
advertisement: Invalid Parameters (0x0d)
btmon, working (legacy) path — same controller:
@ MGMT Command: Add Advertising (0x003e) plen 11
Instance: 1
Flags: 0x00000001 (Switch into Connectable mode)
< HCI Command: LE Set Advertising Parameters (0x08|0x0006)
Own address type: Public (0x00)
> HCI Event: Command Complete — LE Set Advertising Parameters — Status:
Success (0x00)
@ MGMT Event: Command Complete — Add Advertising (0x003e) — Status: Success
(0x00)
The advertising data is 3 bytes (`02 01 06`, the Flags AD) against the
"Available adv data len: 31" reported one line earlier, so it is not a
too-long-data case.
## Scope
Reproduced on two different machines / controllers, both on
7.0.0-28-generic:
- Intel 8265 (Bluetooth 4.2)
- an Intel Bluetooth 5 controller (`btmgmt info` SupportedInstances 20)
Because it also fails on a genuinely extended-advertising-capable BT5
controller, this is the kernel's MGMT `Add Extended Advertising Data`
handler, not a controller/firmware quirk.
## Upstream reference
Identical signature reported and fixed as a **mainline 6.18** regression
(works on 6.12): https://github.com/raspberrypi/linux/issues/7473 — a
length-accounting bug in the `Add Extended Advertising Data` mgmt command
path (introduced when "add advertising" was split into two MGMT commands).
Please backport the upstream fix to the Ubuntu 26.04 `linux` 7.0.0 kernel.
## Regression bracket (from dpkg install log)
2026-06-27 install linux-image-7.0.0-27-generic 7.0.0-27.27 #
advertising works
2026-07-17 install linux-image-7.0.0-28-generic 7.0.0-28.28 #
advertising broken
Confirmed by booting back into 7.0.0-27: `bluetoothctl advertise peripheral`
succeeds again.
## Workaround
Pin/boot `7.0.0-27-generic`.
## Generative AI disclosure
I discovered the issue manually while developing an unrelated
application. I then used Claude Code to both help debug and discover the
Raspberry Pi issue and fix mentioned above. I manually tested kernel
7.0.0-27-generic as a valid workaround.
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Attachment added: "version.log"
https://bugs.launchpad.net/bugs/2161852/+attachment/5986770/+files/version.log
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https://bugs.launchpad.net/bugs/2161852
Title:
linux 7.0.0-28: BLE LE advertising fails — MGMT "Add Extended
Advertising Data" returns Invalid Parameters (0x0d) [regression from
7.0.0-27]
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