[PATCH 6/6][v5] SI_USER: Masquerade si_pid when crossing pid ns boundary

Sukadev Bhattiprolu
2008-12-27T20:57:18Z

From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Date: Wed, 24 Dec 2008 14:14:18 -0800
Subject: [PATCH 6/6][v5] 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 <sukadev@linux.vnet.ibm.com>
---
kernel/signal.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index d90b033..7ffd044 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -951,6 +951,8 @@ 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;
break;
}
} else if (!is_si_special(info)) {
--
1.5.2.5