Re: [PATCH v3] ptrace: Fix fork event messages across pid namespaces

From: Oleg Nesterov
Date: Mon Apr 07 2014 - 15:24:20 EST


On 04/02, Matthew Dempsky wrote:
>
> On Wed, Apr 2, 2014 at 2:58 PM, Matthew Dempsky <mdempsky@xxxxxxxxxx> wrote:
> > Otherwise, it looks like (e.g.) the attempts to get the parent's pid
> > in fill_prstatus() and tomoyo_sys_getppid() are also theoretical races
> > of the same kind?
>
> Doh, nevermind, those functions would potentially be use null "struct
> pid" pointers, not "struct pid_namespace" pointers; and pid_nr_ns()
> guards against pid being null.

Yes, and they want the parent's pid, not ours pid in parent's namespace.

Hmm. In fact I am replying only because I am not sure fill_psinfo() is
correct, perhaps it confuses tid with tgid. I dunno.

Oleg.

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