On Thu, Aug 22, 2013 at 08:45:06PM +0200, Jakub Zawadzki wrote:
> On Thu, Aug 22, 2013 at 09:16:04AM -0700, Guy Harris wrote:
> >
> > On Aug 22, 2013, at 4:46 AM, Anders Broman <anders.broman@xxxxxxxxxxxx> wrote:
> >
> > > Should we add code to enable the JIT compiler from dumpcap?
> >
> > Should I add code to enable the JIT compiler to libpcap while I'm at it?
> >
> > Should the Linux kernel folks enable it by default?
> >
> > I'm inclined to answer "yes" to all three questions. I think the FreeBSD JIT compiler is enabled by default.
> > I'm surprised that the Linux one isn't.
>
> Security issue: http://mainisusuallyafunction.blogspot.com/2012/11/attacking-hardened-linux-systems-with.html
Also it's not perfect like BPF VM, check: https://lkml.org/lkml/2012/3/30/384a
Don't know if such instruction can happen in BPF filter generated by libpcap (Guy?).
If yes we should not enable in on kernels before it was fixed.