[PATCH 7/7][v8] SI_USER: Masquerade si_pid when crossing pid nsboundary

From: Sukadev Bhattiprolu
Date: Wed Feb 18 2009 - 22:08:21 EST



From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
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 <sukadev@xxxxxxxxxxxxxxxxxx>
---
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;
break;
}
} else if (!is_si_special(info)) {
--
1.5.2.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/