> Please check whether the patch in PR 25317 works for you.
> I have been sitting on it for a week or two, waiting to see
> whether it really fixed my problem, and I have had no more trouble
> since then.

I looked the patch -- problem is that the patch patches userland program 
screen.  But the real bug is in kernel -- my screen is not suid and all 
system hangs up.  If non-suid userland program can hang system it is a 
bug in kernel.

I rebuild system from yesterday current -- bug is still here.