Comment 32 for bug 49579

Not a simple fix? Perhaps not, but it's not 5.5 years of complex either. And you listed two solutions, neither of which were good.

Solution: When screen lock seeks to activate, it emits a signal which overrides the mouse and keyboard grabs from all other processes while the screen is locked. Then when the user inputs during the unlock process, the screen lock receives all input. After successfully unlocking, the system 'pops' the screen lock grabs off of a stack and returns the grabs into the previous application. That previous application would see nothing awry, as it would have received no input during the duration, but it would not have received any errors either. This might require modification of the way the x server handles mouse and keyboard grabs, but if the 'hack' were to only allow grab stacking for the screen lock, it shouldn't break compatibility with anything. Simple enough, even if the implementation would require effort.

As far as the wayland and LightDM things go, i dunno. A VT switch? like switching virtual terminals? So.... to hack that machine, I'd need only do ctrl-alt-F7? that seems secure enough. And Wayland will not be ready for 12.04 if I recall correctly, so that's a nonsolution. Businesses need this security, not end users. Businesses use LTS, not regular releases. I hate to be so blunt, but your solution is to wait several more years, and frankly, I'm pretty sure that isn't even remotely an acceptable solution to *anyone* who has been patiently waiting on this to be fixed for 6 years now, especially not business users. Find a better way, or *they* will find Windows, if this is the way security bugs are treated.