4.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sven Eckelmann <sven@xxxxxxxxxxxxx>
[ Upstream commit 6da7be7d24b2921f8215473ba7552796dff05fe1 ]
batman-adv is creating special debugfs directories in the init
net_namespace for each created soft-interface (batadv net_device). But it
is possible to rename a net_device to a completely different name then the
original one.
It can therefore happen that a user registers a new batadv net_device with
the name "bat0". batman-adv is then also adding a new directory under
$debugfs/batman-adv/ with the name "wlan0".
The user then decides to rename this device to "bat1" and registers a
different batadv device with the name "bat0". batman-adv will then try to
create a directory with the name "bat0" under $debugfs/batman-adv/ again.
But there already exists one with this name under this path and thus this
fails. batman-adv will detect a problem and rollback the registering of
this device.
batman-adv must therefore take care of renaming the debugfs directories for
soft-interfaces whenever it detects such a net_device rename.
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx>
Signed-off-by: Simon Wunderlich <sw@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/batman-adv/debugfs.c | 20 ++++++++++++++++++++
net/batman-adv/debugfs.h | 5 +++++
net/batman-adv/hard-interface.c | 34 ++++++++++++++++++++++++++++------
3 files changed, 53 insertions(+), 6 deletions(-)
--- a/net/batman-adv/debugfs.c
+++ b/net/batman-adv/debugfs.c
@@ -434,6 +434,26 @@ out:
}
/**
+ * batadv_debugfs_rename_meshif() - Fix debugfs path for renamed softif
+ * @dev: net_device which was renamed
+ */
+void batadv_debugfs_rename_meshif(struct net_device *dev)
+{
+ struct batadv_priv *bat_priv = netdev_priv(dev);
+ const char *name = dev->name;
+ struct dentry *dir;
+ struct dentry *d;
+
+ dir = bat_priv->debug_dir;
+ if (!dir)
+ return;
+
+ d = debugfs_rename(dir->d_parent, dir, dir->d_parent, name);
+ if (!d)
+ pr_err("Can't rename debugfs dir to %s\n", name);
+}
+
+/**
* batadv_debugfs_del_meshif() - Remove interface dependent debugfs entries
* @dev: netdev struct of the soft interface
*/
--- a/net/batman-adv/debugfs.h
+++ b/net/batman-adv/debugfs.h
@@ -30,6 +30,7 @@ struct net_device;
void batadv_debugfs_init(void);
void batadv_debugfs_destroy(void);
int batadv_debugfs_add_meshif(struct net_device *dev);
+void batadv_debugfs_rename_meshif(struct net_device *dev);
void batadv_debugfs_del_meshif(struct net_device *dev);
int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface);
void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface);
@@ -50,6 +51,10 @@ static inline int batadv_debugfs_add_mes
return 0;
}
+static inline void batadv_debugfs_rename_meshif(struct net_device *dev)
+{
+}
+
static inline void batadv_debugfs_del_meshif(struct net_device *dev)
{
}
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -989,6 +989,32 @@ void batadv_hardif_remove_interfaces(voi
rtnl_unlock();
}
+/**
+ * batadv_hard_if_event_softif() - Handle events for soft interfaces
+ * @event: NETDEV_* event to handle
+ * @net_dev: net_device which generated an event
+ *
+ * Return: NOTIFY_* result
+ */
+static int batadv_hard_if_event_softif(unsigned long event,
+ struct net_device *net_dev)
+{
+ struct batadv_priv *bat_priv;
+
+ switch (event) {
+ case NETDEV_REGISTER:
+ batadv_sysfs_add_meshif(net_dev);
+ bat_priv = netdev_priv(net_dev);
+ batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
+ break;
+ case NETDEV_CHANGENAME:
+ batadv_debugfs_rename_meshif(net_dev);
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
static int batadv_hard_if_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
@@ -997,12 +1023,8 @@ static int batadv_hard_if_event(struct n
struct batadv_hard_iface *primary_if = NULL;
struct batadv_priv *bat_priv;
- if (batadv_softif_is_valid(net_dev) && event == NETDEV_REGISTER) {
- batadv_sysfs_add_meshif(net_dev);
- bat_priv = netdev_priv(net_dev);
- batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
- return NOTIFY_DONE;
- }
+ if (batadv_softif_is_valid(net_dev))
+ return batadv_hard_if_event_softif(event, net_dev);
hard_iface = batadv_hardif_get_by_netdev(net_dev);
if (!hard_iface && (event == NETDEV_REGISTER ||
