Full Disk Encryption (FDE) Emergency Shutdown Feature - Testing Requested

HulaHoop · August 21, 2019, 4:09pm

Summary: shut down a workstation immediately when a magic key combo pressed.
https://phabricator.whonix.org/T553

What I need:

Debian user to press: Alt + Printscreen + o -small case letter not the number

Please do not enable the sysctl. I want to check if this feature is effective on a default install

Qubes user to see if tis works too.

entr0py · September 23, 2016, 5:27pm

It works! Immediate poweroff. FDE password required on start.

Host: Debian 8 + XFCE4

Works regardless of which window has focus. Tested with focus on Host Terminal and also with focus on a Virtualbox Whonix Workstation VM window.

No effect: Qubes 3.1 (Fedora 20) + KDE4

Does not work in dom0 window or in a Debian VM.

HulaHoop · September 23, 2016, 6:40pm

Thanks for testing. documentation updated:

Patrick · September 24, 2016, 1:57pm

In T553#10438, @marmarek wrote:

On Qubes it results in kernel message: sysrq: SysRq : This sysrq operation is disabled.
Default value of /proc/sys/kernel/sysrq on Qubes dom0 is 16. Changing to 1 does not work either:

[1363616.422789] sysrq: SysRq : Power Off
[1363616.423456] xenbus: xenbus_dev_shutdown: backend/console/1069/0: Initialising != Connected, skipping
[1363621.427069] xenbus: xenbus_dev_shutdown: backend/vbd/1069/51760 timeout closing device
[1363626.430065] xenbus: xenbus_dev_shutdown: backend/vbd/1069/51744 timeout closing device
[1363631.434062] xenbus: xenbus_dev_shutdown: backend/vbd/1069/51728 timeout closing device
[1363636.437593] xenbus: xenbus_dev_shutdown: backend/vbd/1069/51712 timeout closing device
[1363636.437595] xenbus: xenbus_dev_shutdown: backend/console/1068/0: Initialising != Connected, skipping
[1363641.441056] xenbus: xenbus_dev_shutdown: backend/vbd/1068/51760 timeout closing device
[1363646.443064] xenbus: xenbus_dev_shutdown: backend/vbd/1068/51744 timeout closing device
[1363651.446038] xenbus: xenbus_dev_shutdown: backend/vbd/1068/51728 timeout closing device
[1363656.447016] xenbus: xenbus_dev_shutdown: backend/vbd/1068/51712 timeout closing device
[1363656.447016] xenbus: xenbus_dev_shutdown: backend/console/1067/0: Initialising != Connected, skipping
[1363661.448050] xenbus: xenbus_dev_shutdown: backend/vbd/1067/51760 timeout closing device
[1363666.451077] xenbus: xenbus_dev_shutdown: backend/vbd/1067/51744 timeout closing device
[1363671.454069] xenbus: xenbus_dev_shutdown: backend/vbd/1067/51728 timeout closing device
[1363676.457060] xenbus: xenbus_dev_shutdown: backend/vbd/1067/51712 timeout closing device
[1363676.457118] xenbus: xenbus_dev_shutdown: backend/console/711/0: Initialising != Connected, skipping
[1363681.460065] xenbus: xenbus_dev_shutdown: backend/vbd/711/51760 timeout closing device

And finally shutdown after timing out for every VM - 20s per VM. Not good, at least.
Sysrq-c makes dom0 frozen for some time (5s?) and then reboots. Also after changing sysctl setting.