From: Oleg Nesterov <oleg@tv-sign.ru>

sys_setpgid() allows to change ->pgrp of ptraced childs.

'man setpgid' does not tell anything about that, so I consider
this behaviour is a bug.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Oren Laadan <orenl@cs.columbia.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 kernel/sys.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

diff -puN kernel/sys.c~setpgid-should-not-accept-ptraced-childs kernel/sys.c
--- devel/kernel/sys.c~setpgid-should-not-accept-ptraced-childs	2005-12-22 05:09:27.000000000 -0800
+++ devel-akpm/kernel/sys.c	2005-12-22 05:09:27.000000000 -0800
@@ -1109,7 +1109,7 @@ asmlinkage long sys_setpgid(pid_t pid, p
 	if (!thread_group_leader(p))
 		goto out;
 
-	if (p->parent == current || p->real_parent == group_leader) {
+	if (p->real_parent == group_leader) {
 		err = -EPERM;
 		if (p->signal->session != group_leader->signal->session)
 			goto out;
_