From 4cecfa6c03410e72e42b520575613c4f30253bef Mon Sep 17 00:00:00 2001
From: Daniel Walsh <dwalsh@redhat.com>
Date: Tue, 3 Jan 2012 21:12:10 +0100
Subject: [PATCH] namespace: remount namespace root dir for SLAVE to avoid
 propagation of mounts from the namespace to the host

https://bugzilla.redhat.com/show_bug.cgi?id=752540
(cherry picked from commit dc4b02006455a4dddeb6ccc1f6656c89d3ebd27c)
---
 src/namespace.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/namespace.c b/src/namespace.c
index 54b22f4..a06cac1 100644
--- a/src/namespace.c
+++ b/src/namespace.c
@@ -266,8 +266,12 @@ int setup_namespace(
                 goto fail;
         }
 
-        /* We assume that by default mount events from us won't be
-         * propagated to the root namespace. */
+        /* Remount / as SLAVE so that nothing mounted in the namespace
+           shows up in the parent */
+        if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
+                r = -errno;
+                goto fail;
+        }
 
         for (p = paths; p < paths + n; p++)
                 if ((r = apply_mount(p, root_dir, inaccessible_dir, private_dir, flags)) < 0)