Linux 7.1 Adds Full HID++ Support for the Latest Logitech Bluetooth Keyboards & Tightens Input Sanitization

The Linux 7.1 release candidate is on the horizon, and the HID subsystem has received a hefty dose of new functionality and security hardening. The changes are split into two main areas:

1. Expanded Logitech HID++ support for a wide range of recent Bluetooth keyboards.
2. Enhanced input sanitization to guard against malicious HID devices.

1. Logitech HID++ – Full Control Over New Bluetooth Keyboards

The logitech‑hidpp driver now recognises a host of newer Bluetooth keyboards. Adding the device IDs was straightforward, but the payoff is substantial: users can now access the full range of HID++ features on these keyboards from Linux.

What HID++ Gives You

• Battery monitoring and management – see real‑time battery levels and trigger low‑power modes.
• Firmware updates – push new firmware directly over the air.
• Advanced configuration – remap keys, adjust lighting, and tweak repeat rates.
• Non‑standard HID features – such as custom keysets for gaming or productivity.

Supported Keyboards

Keyboard Model	Key Features	HID++ Enabled?
Logitech Signature K650 & B2B	Compact, low‑profile	✅
Logitech Pebble Keys 2 K380S	Ultra‑thin, multi‑device	✅
Logitech Casa Pop‑Up Desk & B2B	Desk‑mounted, ergonomic	✅
Logitech Wave Keys & B2B	Wave‑style layout	✅
Logitech Signature Slim K950 & B2B	Slim profile, RGB	✅
Logitech MX Keys S & B2B	Premium keys, RGB	✅
Logitech Keys‑To‑Go 2	Portable, hot‑key support	✅
Logitech Pop Icon Keys	Iconic keys, media controls	✅
Logitech MX Keys Mini & B2B	Compact, silent	✅
Logitech Signature Slim Solar+ K980 B2B	Solar charging, RGB	✅
Logitech Bluetooth Keyboard K250/K251	Classic layout	✅
Logitech Signature Comfort K880 & B2B	Comfortable key travel	✅

These additions were merged overnight into the mainline kernel, and the commit history shows that only device IDs needed to be added – no major driver rewrites. That means the changes land cleanly and are ready for testing in the upcoming 7.1‑rc4.

Build Recommendations

If you’re assembling a homelab or a custom workstation and want to take advantage of HID++ on Linux, consider the following:

Component	Recommendation	Why
CPU	Any recent x86‑64 or ARM Cortex‑A72	HID++ is CPU‑light; modern CPUs handle it comfortably
Kernel	7.1‑rc4 or later	HID++ support is only in 7.1+
Firmware	Keep Logitech firmware up‑to‑date via hidpp tools	Prevents compatibility regressions
Power	Use a UPS or battery backup	HID++ allows battery monitoring – useful for portable setups

The hidpp utilities (hidpp-tool, hidpp-update) are available in most distributions’ repositories and provide a CLI interface to query battery status, update firmware, and tweak key mappings.

2. Input Sanitization – Defending Against Malicious HID Devices

The second major change in the HID merge window is a set of core patches aimed at sanitizing input data from HID devices. The kernel now performs stricter validation on reports, ensuring that malformed or malicious data cannot trigger undefined behavior or security holes.

Why It Matters

• Hardware attacks: A rogue keyboard could send malformed reports to crash the kernel or trigger privilege escalation.
• USB‑to‑Bluetooth bridges: Devices that forward input over Bluetooth can be abused if the kernel trusts the data blindly.
• Supply‑chain security: As more peripherals are shipped with pre‑installed firmware, ensuring the kernel can reject tampered reports is critical.

What the Patch Does

• Validates report lengths against the descriptor.
• Checks that report IDs are within the supported range.
• Rejects reports that exceed the maximum packet size.
• Adds kernel logs for suspicious activity (useful for audit trails).

These changes are part of a broader effort to harden the HID subsystem, and they complement the new HID++ support by ensuring that only well‑formed data reaches the driver.

Build Recommendations

For a hardened homelab:

Component	Recommendation	Why
Kernel	7.1‑rc4 or later with CONFIG_HID_INPUT_SANE enabled	Sanitization patches live in the core HID code
Monitoring	auditd or syslog with high verbosity for HID events	Detect suspicious reports early
Firmware	Verify device firmware hashes	Prevent tampered devices from being accepted

Conclusion

The Linux 7.1 release candidate brings practical improvements for everyday users and a solid security boost for administrators. With full HID++ support for a wide array of Logitech Bluetooth keyboards, you can now manage battery life, firmware, and key layouts directly from Linux. At the same time, the kernel’s enhanced input sanitization protects against malicious HID hardware, a critical layer of defense in an era where peripherals can be weaponised.

If you’re building a homelab or a custom workstation, these changes mean you can rely on Linux to give you both flexibility and security out of the box.

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