bluetooth: fix PS3 pairing with recent BlueZ

[cmitu]

Due to changes in BlueZ added to fix CVE-2023-45866, the PS3 controllers won't pair/work anymore with BlueZ. Since the path consist in only one change to default option (ClassicBondedOnly default changed, see [1]), it's been quickly added by all distros [2], [3]. This has already been reported in the forums and fixed (for Buster) by downgrading the bluez package. The same fix cannot be applied to current distros, so we can switch back the option to the way it works with PS3 controllers.

NOTE:

• while technically this makes BlueZ vulnerable to CVE-2023-45866, the exploit mentioned works IIF BlueZ is set to 'discoverable' mode. However, this mode is set only during discoveries, which in RetroPie means just the pairing dialog - I think the risk for a real break-in through the vulnerability described is very low. See [4] for an explanation of the conditions needed to exploit it on BlueZ and a PoC (which didn't work for me, despite having the vulnerable config in place).
• the configuration is set-up only when a PS3 pairing attempt is made.
• when removing a device, the vulnerable configuration will also be removed if no more PS3 paired devices are left.

[1] https://git.kernel.org/pub/scm/bluetooth/bluez.git/commit/profiles/input?id=25a471a83e02e1effb15d5a488b3f0085eaeb675 [2] https://ubuntu.com/security/CVE-2023-45866 [3] https://security-tracker.debian.org/tracker/CVE-2023-45866 [4] https://github.com/marcnewlin/hi_my_name_is_keyboard?tab=readme-ov-file#linux-keystroke-injection

[cmitu]

Forgot to mention that the workaround/configuration has to be in-place even after pairing, otherwise re-connecting the controller doesn't work.

[joolswills]

Thank you.