Linux Support Is Coming To Allow De-Authorizing Thunderbolt Devices

Written by Michael Larabel in Hardware on 18 January 2021 at 08:27 AM EST. 11 Comments
While in recent years there has been growing interest in enhancing Linux's Thunderbolt security with offering security levels and other functionality to authorize supported/known Thunderbolt devices, surprisingly it's taken until 2021 to see the ability for Linux's Thunderbolt software connection manage to handle de-authorizing devices.

If wanting to de-authorize a previously authorized Thunderbolt device for whatever reason or if wanting to establish policies like where on user log-out that devices would be automatically de-authorized, it's looking like Linux 5.12 will support this ability.

Queued this past week into the Thunderbolt dev tree is the subsystem support for de-authorizing Thunderbolt devices. The de-authorization support relies upon the Thunderbolt software connection manager being active as it's able to directly control the PCIe tunnels.

A new "deauthorization" sysfs attribute is exposed to indicate whether the system supports de-authorization of Thunderbolt devices. Specific devices can then be deauthorized by writing "0" to the "authorized" sysfs attribute.

This is the kernel side support while we will see once landed if any user-space policies are proposed for automatically de-authorizing Thunderbolt devices on log-out or other changes in the name of system security.
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Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via

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