Messages in this thread |  | | | Date | Sun, 15 Jan 2012 19:48:06 +0100 | | From | Oleg Nesterov <> | | Subject | Re: [RFC] fs, proc: Introduce /proc/<pid>/task/<tid>/children entry v5 |
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On 01/15, Cyrill Gorcunov wrote: > > On Sun, Jan 15, 2012 at 07:07:21PM +0100, Oleg Nesterov wrote: > > > > Again. I simply can't understand what ptrace_may_access() actually > > means. Why do we use the possible child, not parent? > > > > IOW. I have no idea if we really need any security check at all. > > You can find the children pids without this patch anyway via. > > grep PPid /proc/*/status. > > > > OK, I see. I am actually not sure which behaviour should be there. > What should we do if say we have a task with a number of children, > which changed permissions of own and some of children. Look what I mean. > > We have say tid A, which has children B C D, and when we read > /proc/pid/task/tid/children we should see "B C D" here. But > what if say A started with roots rights, then changed own permission > so everyone could read this /proc/pid/task/<A>/children, but > left C with root permissions only. So should we list C here?
Why not? What is the problem to know the pid of this child? And once again, you can list all children without this patch anyway.
Perhaps I missed something, but I simply don't understand the problem.
Oleg.
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