Messages in this thread | | | Date | Tue, 29 Dec 2009 10:39:39 -0600 | From | "Serge E. Hallyn" <> | Subject | Re: RFC: disablenetwork facility. (v4) |
| |
Quoting Bryan Donlan (bdonlan@gmail.com): > On Tue, Dec 29, 2009 at 10:11 AM, Serge E. Hallyn <serue@us.ibm.com> wrote: > > Eric, let me specifically point out a 'disable setuid-root' > > problem on linux: root still owns most of the system even when > > it's not privileged. So does "disable setuid-root" mean > > we don't allow exec of setuid-root binaries at all, or that > > we don't setuid to root, or that we just don't raise privileges > > for setuid-root? > > I, for one, think it would be best to handle it exactly like the > nosuid mount option - that is, pretend the file doesn't have any > setuid bits set. There's no reason to deny execution; if the process > would otherwise be able to execute it, it can also copy the file to > make a non-suid version and execute that instead. And some programs > can operate with reduced function without setuid. For example, screen > comes to mind; it needs root to share screen sessions between multiple > users, but can operate for a single user just fine without root, and > indeed the latter is usually the default configuration.
That's fine with me, seems safe for a fully unprivileged program to use, and would make sense to do through one of the securebits set with prctl(PR_SET_SECUREBITS).
In addition, I assume we would also refuse to honor file capabilities?
-serge -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |