Re: RFC: fsyscall

Serge E. Hallyn
2015-09-10T13:28:14Z

On Wed, Sep 09, 2015 at 06:27:06PM +0100, David Drysdale wrote:
> On Wed, Sep 9, 2015 at 1:25 AM, Eric W. Biederman <ebiederm@xmission.com> wrote:
> > Andy Lutomirski <luto@amacapital.net> writes:
> > > On Tue, Sep 8, 2015 at 4:07 PM, Eric W. Biederman <ebiederm@xmission.com> wrote:
>
> (From this perspective, the limitation that seccomp-bpf programs only
> have access to syscall arguments by-value is actually a help -- the filter
> can't look into user memory, so can't be fooled by having memory
> contents changed underneath it. Of course, if the eBPF stuff ever
> changes that we should watch out...)

Yup and I'm quite sure I've seen that raised as a reason to refuse
supporting exactly that.