* Martin Ebourne <lists(a)ebourne.me.uk> [2006-05-12 17:19]:
On Fri, 2006-05-12 at 15:46 +0200, Marten Lehmann wrote:
> > If the quota limits need to be as strict as your first message indicates, then
> > I'm surprised you haven't already had /tmp/ on a separate filesystem,
with
> > separate quotas set. Additionally, I always split off /tmp/ so *if* it
> > fills, it doesn't "damage" my root filesystem.
>
> Actually, /home is not part of the root-partition and /tmp could be a
> symlink to /home/tmp so both can use the some quota definitions. But how
> can I setup a system-wide policy that disallows to execute files from
> /tmp or /home/tmp?
That sounds like a very hard way of doing things. And difficult to prove
correct too.
How about:
mkdir /home/tmp
mount -o bind,noexec,nosuid /home/tmp /tmp
I don't think this will work. I just tried to do it and I could still
execute files in the mounted dir. I thought that per-mountpoint noexec
flags were in the kernel, but I can't find any definitive information on
it and fs/namespace.c is not the best information source either. (Anyone
knows why this doesn't work? It would be really neat.)
The other issue here is that the user still can execute files through
/home/tmp. So you should --move the dir instead of bind-mounting it.
Thomas