busybox 1.19.3 cp bug w.r.t device files?

[Joakim Tjernlund]

Denys Vlasenko <vda.linux at googlemail.com> wrote on 2011/12/21 14:54:07:
>
> On Wed, Dec 21, 2011 at 2:38 PM, Joakim Tjernlund
> <joakim.tjernlund at transmode.se> wrote:
> > Denys Vlasenko <vda.linux at googlemail.com> wrote on 2011/12/21 13:08:30:
> >>
> >> On Wed, Dec 21, 2011 at 12:31 PM, Joakim Tjernlund
> >> <joakim.tjernlund at transmode.se> wrote:
> >> >
> >> > Recently installed bb 1.19.3 (gentoo) on our ppc target. Today I discovered
> >> > that cp vmlinux /dev/mtdblock5 dosn't work. The device file is removed and
> >> > a new plain file is created instead.
> >> > Feels like a bb bug, comments?
> >>
> >> config FEATURE_NON_POSIX_CP
> >>         bool "Non-POSIX, but safer, copying to special nodes"
> >>         default y
> >>         help
> >>           With this option, "cp file symlink" will delete symlink
> >>           and create a regular file. This does not conform to POSIX,
> >>           but prevents a symlink attack.
> >>           Similarly, "cp file device" will not send file's data
> >>           to the device. (To do that, use "cat file >device")
> >
> > Not 100% sure how to read this. I have CONFIG_FEATURE_NON_POSIX_CP=y
> > already. Should I change to CONFIG_FEATURE_NON_POSIX_CP=n?
>
> Yes. (however, I personally think it's better to use cat, not cp,
> for the operation you are trying to perform)

OK, thanks. Will fix the app too but for now I must play it safe and enable
the old way as else older versions of out app will break.

Thanks for your patience

     Jocke