Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [PATCH v6] Added PR_SET_PROCTITLE_AREA option for prctl() | Date | Thu, 10 Dec 2009 09:16:09 +0900 (JST) |
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> > * KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote: > > > > > > > * Bryan Donlan <bdonlan@gmail.com> wrote: > > > > > > > On Tue, Dec 8, 2009 at 12:38 AM, Ingo Molnar <mingo@elte.hu> wrote: > > > > > > > > > > * KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote: > > > > > > > > > >> > The feature looks useful, but the choice of a prctl as an API is strange > > > > >> > - it limits us to the current task only - while the ability to set > > > > >> > arguments for another task looks a more generic (and potentially more > > > > >> > useful) solution. > > > > >> > > > > >> No. It's impossible. > > > > >> /proc/{pid}/cmdline read user process's memory. iow, this prctl() don't > > > > >> receive string, it receive virtual address itself. [...] > > > > > > > > > > it's not 'impossible' at all, you yourself mention ptrace: > > > > > > > > If another process is going to use ptrace to inject the cmdline string > > > > into the victim's address space, it can also temporarily hijack a > > > > thread to run prctl() on its behalf... > > > > > > That's exactly the point i made. There's no reason not to offer the API > > > i suggested as long as permissions are checked (as usual) - because > > > ptrace already allows this (and more). > > > > Confused. > > > > I think ptrace don't solve the issue of explained my patch description. > > it doesnt. By 'this' i meant the security aspect. ptrace can already do > almost arbitrary alteration to any task's state.
Ah, I misunderstood. Thanks correct me :)
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