From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Date: Wed, 23 Sep 2009 22:57:22 +0000 (-0700)
Subject: pidns: deny CLONE_PARENT|CLONE_NEWPID combination
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=e5a4738699d6eca408dcb225bd350413927701e2;p=openwrt%2Fstaging%2Fblogic.git

pidns: deny CLONE_PARENT|CLONE_NEWPID combination

CLONE_PARENT was used to implement an older threading model.  For
consistency with the CLONE_THREAD check in copy_pid_ns(), disable
CLONE_PARENT with CLONE_NEWPID, at least until the required semantics of
pid namespaces are clear.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Oren Laadan <orenl@cs.columbia.edu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 821722ae58a7..86b3796b0436 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -118,7 +118,7 @@ struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old
 {
 	if (!(flags & CLONE_NEWPID))
 		return get_pid_ns(old_ns);
-	if (flags & CLONE_THREAD)
+	if (flags & (CLONE_THREAD|CLONE_PARENT))
 		return ERR_PTR(-EINVAL);
 	return create_pid_namespace(old_ns);
 }