[PATCH 5/5] net: Block MSG_CMSG_COMPAT in send(m)msg and recv(m)msg

[Eric Dumazet]

On Thu, 2013-06-06 at 12:56 +1000, Michael Neuling wrote:
> On Thu, May 23, 2013 at 7:07 AM, Andy Lutomirski <luto at amacapital.net> wrote:
> > MSG_CMSG_COMPAT is (AFAIK) not intended to be part of the API --
> > it's a hack that steals a bit to indicate to other networking code
> > that a compat entry was used.  So don't allow it from a non-compat
> > syscall.
> 
> Dave & Linus
> 
> This is causing a regression on 64bit powerpc with 32bit usermode.
> When I hit userspace, udev is broken and I suspect all networking is
> broken as well.
> 
> Can we please revert 1be374a0518a288147c6a7398792583200a67261 upstream?
> 

It seems to also break x86_64, if using 32bit usermode.