Re: BUG: unable to handle kernel paging request from pty_write [was: Linux 4.4.2]

[Borislav Petkov]

On Fri, Feb 26, 2016 at 10:05:26AM -0800, Linus Torvalds wrote:
> Of course, if Jiri isn't actually running this on an AMD CPU, that
> theory flies right out the window. But we do have a reported oops on
> the security list that looks totally different in the big picture, but
> shares the exact same "corrupted stack pointer register state
> resulting in crazy instruction pointer, resulting in NX fault"
> behavior in the end.
> 
> In the other case, microcode patchlevel 0x0600081c was fine, and
> 0x06000832 is the one exhibiting the corruption problem.
> 
> I've contacted Robert ÅwiÄcki (who found the microcode problem) in
> case he wants to weigh in in this thread.. He was talking to some AMD
> people, but I don't know the exactly who.

It most likely is that problem. If Jiri is using the IBS machines -
and from quick look at http://labs.suse.cz/jslaby/bug-968218/gdb_log,
it looks like he is, then they are exactly those boxes with a b0rked
microcode patch. AMD is working on a fix.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.