Re: [PATCH] Revert "Bluetooth: Align minimum encryption key size for LE and BR/EDR connections"

[Johan Hedberg]

Hi,

On 12 Jun 2019, at 12.38, Bastien Nocera <hadess@xxxxxxxxxx> wrote:
> 
> On Wed, 2019-06-12 at 09:07 +0200, Greg Kroah-Hartman wrote:
>> On Tue, Jun 11, 2019 at 11:36:26PM +0200, Marcel Holtmann wrote:
>>> Hi Vasily,
>>> 
>>>> Can we get this revert merged into stable branches? Bluetooth HID
>>>> has
>>>> been broken for many devices for quite a while now and RFC patch
>>>> that
>>>> fixes the breakage hasn't seen any movement for almost a month.
>>> 
>>> lets send the RFC patch upstream since it got enough feedback that
>>> it fixes the issue.
>> 
>> According to Hans, the workaround did not work.
> 
> Is it possible that those folks were running Fedora, and using a
> version of bluetoothd without a fix for using dbus-broker as the D-Bus
> daemon implementation?
> 
> I backported the fix in an update last week:
> https://bugzilla.redhat.com/show_bug.cgi?id=1711594

I donât know if thatâs the case, but at least based on the comment here:

https://bugzilla.kernel.org/show_bug.cgi?id=203643#c10

it looks like thereâs still a race with controllers that do support reading the encryption key size. The peer device may send an L2CAP Connect Request before weâve completed reading the key size, in which case weâd still reject the request. For making this work again Iâm not aware of any other quick solution than a revert.

Johan