Re: Linux 7.1-rc3 regression (Bluetooth)

From: Thorsten Leemhuis

Date: Mon May 11 2026 - 02:30:30 EST


On 5/11/26 07:17, markus.suvanto@xxxxxxxxx wrote:
> Hello
>
> I upgrade 7.1-rc2 to 7.1-rc3. After that bluetooth didn't start
> hci0: Failed to send wmt func ctrl (-22)
> My fix was to revert commit 634a4408c0615c523cf7531790f4f14a422b9206

Thx for your report. FWIW, there are two proposed fixed for this change
floating around:

https://lore.kernel.org/all/20260508173121.27526-1-mikhail.v.gavrilov@xxxxxxxxx/
https://lore.kernel.org/all/770d36b07311bf88210c187923f243fb9f126f04.1777058551.git.pav@xxxxxx/

Given that this is the third revert within a short time-frame I wonder
if we should fast-track a fix (once ready) to spare more users the pain
of bisecting & reporting.

Ciao, Thorsten

> -Markus Suvanto
>
>
> commit 994246ea1eed9029d648b28a9828359f5046173e (HEAD -> master)
> Author: Markus Suvanto <markus.suvanto@xxxxxxxxxxxx>
> Date: Mon May 11 07:29:47 2026 +0300
>
> Revert "Bluetooth: btmtk: validate WMT event SKB length before struct access"
>
> This reverts commit 634a4408c0615c523cf7531790f4f14a422b9206.
>
> commit 5d6919055dec134de3c40167a490f33c74c12581 (tag: v7.1-rc3, origin/master, origin/HEAD)
> Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Date: Sun May 10 14:08:09 2026 -0700
>
> Linux 7.1-rc3
>
>
> Lenovo ThinkPad T14s Gen 1 (20UJ) AMD Ryzen 5 PRO 4650U
>
> Not working dmesg:
> masu@t470 ~ % grep Bluetoot dmesg_7.1.0-rc3
> [ 4.229749] Bluetooth: Core ver 2.22
> [ 4.232923] Bluetooth: HCI device and connection manager initialized
> [ 4.233081] Bluetooth: HCI socket layer initialized
> [ 4.233227] Bluetooth: L2CAP socket layer initialized
> [ 4.233236] Bluetooth: SCO socket layer initialized
> [ 4.413060] Bluetooth: hci0: HW/SW Version: 0x008a008a, Build Time: 20251223091725
> [ 6.142372] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
> [ 6.142384] Bluetooth: BNEP filters: protocol multicast
> [ 6.142393] Bluetooth: BNEP socket layer initialized
> [ 7.727087] Bluetooth: hci0: Failed to send wmt func ctrl (-22)
> [ 7.727140] Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported.
>
>
> Working dmesg:
> masu@t470 ~ % grep Bluetoot dmesg_7.1.0-rc3-00001-g994246ea1eed
> [ 4.296358] Bluetooth: Core ver 2.22
> [ 4.296385] Bluetooth: HCI device and connection manager initialized
> [ 4.296393] Bluetooth: HCI socket layer initialized
> [ 4.296399] Bluetooth: L2CAP socket layer initialized
> [ 4.296404] Bluetooth: SCO socket layer initialized
> [ 4.391514] Bluetooth: hci0: HW/SW Version: 0x008a008a, Build Time: 20251223091725
> [ 6.087152] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
> [ 6.087165] Bluetooth: BNEP filters: protocol multicast
> [ 6.087172] Bluetooth: BNEP socket layer initialized
> [ 7.591891] Bluetooth: hci0: Device setup in 3127955 usecs
> [ 7.591922] Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported.
> [ 7.657339] Bluetooth: MGMT ver 1.23
> [ 25.883135] Bluetooth: RFCOMM TTY layer initialized
> [ 25.883150] Bluetooth: RFCOMM socket layer initialized
> [ 25.883154] Bluetooth: RFCOMM ver 1.11