Messages in this thread | | | From | (Eric W. Biederman) | Subject | Re: [PATCH -mm 5/7] add user namespace | Date | Fri, 14 Jul 2006 13:07:14 -0600 |
| |
Dave Hansen <haveblue@us.ibm.com> writes:
> On Fri, 2006-07-14 at 12:06 -0600, Eric W. Biederman wrote: >> > On Fri, 2006-07-14 at 11:18 -0600, Eric W. Biederman wrote: >> >> /proc/<pid>/fd/... >> >> /proc/<pid>/exe >> >> /proc/<pid>/cwd >> >> >> >> It isn't quite the same as you are actually opening a second >> >> copy of the file descriptor but the essence is the same. >> > >> > Last I checked, those were symlinks and didn't work for things like >> > deleted files. Am I wrong? >> >> Yes. They are not really symlinks. >> >> Wanting to have an executable that was deleted after it was done >> executing. I wrote it to a file. opened it, unlinked it, set close >> on exec, and the exec'd it with /proc/self/fd/N. > > Well, on one hand, it makes checkpoints with deleted files easier ;) > > Now that I'm actually looking at the code, isn't > proc_fd_access_allowed()'s permission just derived from ptrace > permissions? It doesn't seem to involve uids directly at all!
You still have to actually open the file and from there you get to permission().
Eric - 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/
| |