Messages in this thread | | | Date | Tue, 20 Sep 2011 13:53:54 -0500 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH] user namespace: make signal.c respect user namespaces |
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Quoting Oleg Nesterov (oleg@redhat.com): > On 09/19, Serge E. Hallyn wrote: > > > > __send_signal: convert the uid being sent in SI_USER to the target task's > > user namespace. > > > > do_notify_parent and do_notify_parent_cldstop: map task's uid to parent's > > user namespace > > > > ptrace_signal: map parent's uid into current's user namespace before > > including in signal to current. > > Btw, what about the other users of ->si_uid? Say, kill() or tkill().
Well, they end up calling __send_signal().
> Looks like, we need a lot of complications to make this correct... > > As for send_signal(), may be we can simply do > > > --- x/kernel/signal.c > +++ x/kernel/signal.c > @@ -1084,10 +1084,13 @@ static int __send_signal(int sig, struct > break; > default: > copy_siginfo(&q->info, info); > - if (from_ancestor_ns) > - q->info.si_pid = 0; > break; > } > + > + if (unlikely(from_ancestor_ns)) { > + q->info.si_pid = 0; > + q->info.si_uid = 0; > + } > } else if (!is_si_special(info)) { > if (sig >= SIGRTMIN && info->si_code != SI_USER) { > /* > > ? > > Yes, this "breaks" sys_rt_sigqueueinfo() evem more if it is used > to send the signal to the sub-namespace.
Eh, yeah, so we do have to use the user_ns_map_uid(), or rather your new helper.
But you sound more alarmed than that. So I might be missing something. You think that user_ns_map_uid() at the locations I identified in kernel/signal.c does not suffice?
-serge
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