On 2/2/2015 12:37 PM, Andy Lutomirski wrote: > On Mon, Feb 2, 2015 at 10:08 AM, Serge Hallyn <serge.hal...@ubuntu.com> wrote: >> Quoting Casey Schaufler (ca...@schaufler-ca.com): >>> I'm game to participate in such an effort. The POSIX scheme >>> is workable, but given that it's 20 years old and hasn't >>> developed real traction it's hard to call it successful. >> Over the years we've several times discussed possible reasons for this >> and how to help. I personally think it's two things: 1. lack of >> toolchain and fs support. The fact that we cannot to this day enable >> ping using capabilities by default because of cpio, tar and non-xattr >> filesystems is disheartening. 2. It's hard for users and applications >> to know what caps they need. yes the API is a bear to use, but we can >> hide that behind fancier libraries. But using capabilities requires too >> much in-depth knowledge of precisely what caps you might need for >> whatever operations library may now do when you asked for something. > None of this could address the problem here, though: if I hold a > capability and I want to pass that capability to an exec'd helper, I > shouldn't need the fs's help to do this.
One of the holes in the 1003.1e spec is what to do with a program file that does not have a capability set attached to it. The two options are drop all capabilities and leave the capabilities alone. The latter gives you what you're asking for. The former is arguably safer. > > --Andy > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/