make sure a process parent of a pidspace discards signals sent
from processes in that pidspace.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>

--

 kernel/signal.c |    4 ++++
 1 files changed, 4 insertions(+)

Index: linux-2.6.15-rc1/kernel/signal.c
===================================================================
--- linux-2.6.15-rc1.orig/kernel/signal.c	2005-12-08 01:50:37.000000000 -0500
+++ linux-2.6.15-rc1/kernel/signal.c	2005-12-08 01:50:37.000000000 -0500
@@ -651,6 +651,10 @@ static int check_kill_permission(int sig
 	if (!valid_signal(sig))
 		return error;
 	error = -EPERM;
+
+	if (task_vpid_ctx(t, current) == 1)
+	    return error;
+
 	if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)))
 	    && ((sig != SIGCONT) ||
 		(current->signal->session != t->signal->session))

--