[PATCH 8/9] bridge: make sure objects belong to container's owner

[Tyler Hicks]

BugLink: https://launchpad.net/bugs/1784501

When creating various bridge objects in /sys/class/net/... make sure
that they belong to the container's owner instead of global root (if
they belong to a container/namespace).

Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit 705e0dea4d52ef420a7d37fd9cc6725092e5e1ff)
Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
---
 net/bridge/br_if.c       | 9 +++++++++
 net/bridge/br_private.h  | 2 ++
 net/bridge/br_sysfs_if.c | 5 ++---
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 4be5335407c5..20629d142bd0 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -26,6 +26,7 @@
 #include <net/sock.h>
 #include <linux/if_vlan.h>
 #include <net/switchdev.h>
+#include <net/net_namespace.h>
 
 #include "br_private.h"
 
@@ -199,11 +200,19 @@ static void release_nbp(struct kobject *kobj)
 	kfree(p);
 }
 
+static void brport_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
+{
+	struct net_bridge_port *p = kobj_to_brport(kobj);
+
+	net_ns_get_ownership(dev_net(p->dev), uid, gid);
+}
+
 static struct kobj_type brport_ktype = {
 #ifdef CONFIG_SYSFS
 	.sysfs_ops = &brport_sysfs_ops,
 #endif
 	.release = release_nbp,
+	.get_ownership = brport_get_ownership,
 };
 
 static void destroy_nbp(struct net_bridge_port *p)
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 1312b8d20ec3..14224384e4d5 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -278,6 +278,8 @@ struct net_bridge_port {
 	u16				group_fwd_mask;
 };
 
+#define kobj_to_brport(obj)	container_of(obj, struct net_bridge_port, kobj)
+
 #define br_auto_port(p) ((p)->flags & BR_AUTO_MASK)
 #define br_promisc_port(p) ((p)->flags & BR_PROMISC)
 
diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index 126a8ea73c96..4cfad3735d35 100644
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c
@@ -247,13 +247,12 @@ static const struct brport_attribute *brport_attrs[] = {
 };
 
 #define to_brport_attr(_at) container_of(_at, struct brport_attribute, attr)
-#define to_brport(obj)	container_of(obj, struct net_bridge_port, kobj)
 
 static ssize_t brport_show(struct kobject *kobj,
 			   struct attribute *attr, char *buf)
 {
 	struct brport_attribute *brport_attr = to_brport_attr(attr);
-	struct net_bridge_port *p = to_brport(kobj);
+	struct net_bridge_port *p = kobj_to_brport(kobj);
 
 	if (!brport_attr->show)
 		return -EINVAL;
@@ -266,7 +265,7 @@ static ssize_t brport_store(struct kobject *kobj,
 			    const char *buf, size_t count)
 {
 	struct brport_attribute *brport_attr = to_brport_attr(attr);
-	struct net_bridge_port *p = to_brport(kobj);
+	struct net_bridge_port *p = kobj_to_brport(kobj);
 	ssize_t ret = -EINVAL;
 	char *endp;
 	unsigned long val;
-- 
2.7.4