Messages in this thread | | | Date | Tue, 11 Jul 2006 17:06:25 +0200 | From | Cedric Le Goater <> | Subject | Re: [PATCH -mm 7/7] forbid the use of the unshare syscall on ipc namespaces |
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Kirill Korotaev wrote:
> This patch looks as an overkill for me.
it's a standalone patch. It can be dropped. I think there is some value to it as we already agree
> If you really care about things you describe, you can forbid unsharing > in cases: > > 1. > undo_list = tsk->sysvsem.undo_list; > if (undo_list) > REFUSE_UNSHARE; > 2. vma exists with vma->vm_ops == &shm_vm_ops; > 3. file opened with f_op == &shm_file_operations
and there are also the netlink sockets mq_notify.
OK, so we agree that ipc namespaces cannot be unshared without extra checks. I like the firewall approach : it's not safe, don't allow it. Which is what the patch is doing : we can't unshare ipc namespace safely so let's just forbid it :
if (unshare_flags & CLONE_NEWIPC) goto bad_unshare_out;
simple, nop ? :)
> I also dislike exec() operation for such sort of things since you can > have no executable at hands due to changed fs namespace.
what do you mean ? fs namespace doesn't change bc you need it to load the new process image/interpreter.
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