From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: [PATCH 7/7][v8] SI_USER: Masquerade si_pid when crossing pid ns boundary Date: Thu, 19 Feb 2009 08:11:06 -0800 Message-ID: References: <20090219030207.GA18783@us.ibm.com> <20090219030743.GG18990@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20090219030743.GG18990@us.ibm.com> (Sukadev Bhattiprolu's message of "Wed\, 18 Feb 2009 19\:07\:43 -0800") Sender: linux-kernel-owner@vger.kernel.org To: Sukadev Bhattiprolu Cc: Andrew Morton , Oleg Nesterov , roland@redhat.com, daniel@hozac.com, Containers , linux-kernel@vger.kernel.org List-Id: containers.vger.kernel.org Sukadev Bhattiprolu writes: > From: Sukadev Bhattiprolu > Date: Wed, 24 Dec 2008 14:14:18 -0800 > Subject: [PATCH 7/7][v8] SI_USER: Masquerade si_pid when crossing pid ns > boundary > > When sending a signal to a descendant namespace, set ->si_pid to 0 since > the sender does not have a pid in the receiver's namespace. > > Note: > - If rt_sigqueueinfo() sets si_code to SI_USER when sending a > signal across a pid namespace boundary, the value in ->si_pid > will be cleared to 0. > > Changelog[v5]: > - (Oleg Nesterov) Address both sys_kill() and sys_tkill() cases > in send_signal() to simplify code (this drops patch 7/7 from > earlier version of patchset). > > Signed-off-by: Sukadev Bhattiprolu > --- > kernel/signal.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/kernel/signal.c b/kernel/signal.c > index c94355b..a416d77 100644 > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -883,6 +883,8 @@ static int __send_signal(int sig, struct siginfo *info, > struct task_struct *t, > break; > default: > copy_siginfo(&q->info, info); > + if (from_ancestor_ns) > + q->info.si_pid = 0; This is wrong. siginfo is a union and you need to inspect code to see if si_pid is present in the current union. Eric