From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Subject: Re: [PATCH 6/6] ebpf: allow BPF_REG_X in src_reg conditional jumps
Date: Fri, 4 Sep 2015 21:12:52 -0700
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Cc: Kees Cook <keescook@chromium.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Will Drewry <wad@chromium.org>,
	Oleg Nesterov <oleg@redhat.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Pavel Emelyanov <xemul@parallels.com>,
	"Serge E. Hallyn" <serge.hallyn@ubuntu.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org
To: Tycho Andersen <tycho.andersen@canonical.com>
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On Fri, Sep 04, 2015 at 04:43:50PM -0600, Tycho Andersen wrote:
> > The fix should be something like this:
> > diff --git a/net/core/filter.c b/net/core/filter.c
> > index 13079f03902e..05a04ea87172 100644
> > --- a/net/core/filter.c
> > +++ b/net/core/filter.c
> > @@ -478,9 +478,9 @@ do_pass:
> >                                 bpf_src = BPF_X;
> >                         } else {
> >                                 insn->dst_reg = BPF_REG_A;
> > -                               insn->src_reg = BPF_REG_X;
> >                                 insn->imm = fp->k;
> >                                 bpf_src = BPF_SRC(fp->code);
> > +                               insn->src_reg = bpf_src == BPF_X ? BPF_REG_X : 0;
> >                         }
> 
> Yep, I just tested this and it works for me. Do you want to manage it
> or should I carry it as part of this set?

Though it's a bug, it doesn't affect anything at the moment
and not worth fixing in net, so please submit it as separate bug
fix when net-next reopens. imo the rest of the patches should
also go via net-next to minimize cross-tree conflicts.