Messages in this thread |  | | Date | Tue, 4 Jun 96 01:23 BST | From | Jamie Lokier <> | Subject | Re: /proc/self/exe unreadable by suid programs |
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>>>>> "Marek" == Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl> writes:
Marek> It's not that simple - how about ftpd? The user who is Marek> logged in would be able to read the address space of the ftpd Marek> process. Not good - for example, some data from /etc/shadow Marek> might be left in stdio buffers. /proc/<pid>/fd would be Marek> another security hole - the user would get access to any Marek> files open by ftpd (/etc/shadow, wtmp etc.).
Ok, I hadn't thought of that. You're right.
Everyone whose listening: don't install the patch. Especially Linus :-)
Marek> If you really need this change, please make it a /proc mount Marek> option which is off by default (called "insecure" for Marek> example). It is not a good idea, maybe except for single Marek> user systems where security is usually not very important Marek> anyway...
Whilst I would like to use it, I can't accept such a security problem. For a start, my system is used by many users who I trust, but not to the extent that they know exactly what they're doing with my Linux box. It's very much a file server too. So I am concerned about security. (Someone nearly deleted all the files on the network with `rm -rf' -- since then, `root' is available to fewer people even if it does get in the way, ever so slightly, of the sense of trust between me and my coworkers).
Besides, I want to use /proc/self/exe in a commercial SVGALIB program distributed on CD. (Well really it's a DOS/Windows 95 program, but as we have a fully working Linux version, I'll probably slip that on too).
Ta, -- Jamie
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