Secure attention Key: Login and GkSudo

Reinhard Tartler siretart at
Sun Oct 30 18:37:38 UTC 2011

On So, Okt 30, 2011 at 15:11:04 (CET), staticd wrote:

>> Windows NT is designed so that, unless system security is already
>> compromised in some other way, only the Winlogon process, a trusted
>> system process, can receive notification of this keystroke
>> combination. This is because the kernel remembers the process ID of
>> the Winlogon process, and allows only that process to receive the
>> notification.
>> So says Wikipedia.
>> Interestingly, VMWare catches the sequence as well.
> I was thinking of a Alt+Sysrq combination capturable only by the kernel.
> (Ctrl+Alt+Sysrq ?)

The SAK for Linux systems is Alt+Sysrq+k

While this SAK can be disabled, Ubuntu ships with this functionality
enabled. It safely and uncatchably terminates your running X11 session,
returning back to your login manager.


Reinhard Tartler, KeyID 945348A4

More information about the Ubuntu-devel-discuss mailing list