From 36dc621ceca1be3ec885aeade5fdafbbcc452a6d Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Fri, 1 Jun 2018 19:24:23 +0200 Subject: batman-adv: Fix debugfs path for renamed hardif batman-adv is creating special debugfs directories in the init net_namespace for each valid hard-interface (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 net_device which gets the name "wlan0" assigned by default. batman-adv is also adding a new directory under $debugfs/batman-adv/ with the name "wlan0". The user then decides to rename this device to "wl_pri" and registers a different device. The kernel may now decide to use the name "wlan0" again for this new device. batman-adv will detect it as a valid net_device and tries to create a directory with the name "wlan0" under $debugfs/batman-adv/. 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 hard-interfaces whenever it detects such a net_device rename. Fixes: 5bc7c1eb44f2 ("batman-adv: add debugfs structure for information per interface") Reported-by: John Soros Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/debugfs.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'net/batman-adv/debugfs.c') diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c index 4229b01ac7b5..7e5de7b9f6d5 100644 --- a/net/batman-adv/debugfs.c +++ b/net/batman-adv/debugfs.c @@ -19,6 +19,7 @@ #include "debugfs.h" #include "main.h" +#include #include #include #include @@ -343,6 +344,25 @@ out: return -ENOMEM; } +/** + * batadv_debugfs_rename_hardif() - Fix debugfs path for renamed hardif + * @hard_iface: hard interface which was renamed + */ +void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface) +{ + const char *name = hard_iface->net_dev->name; + struct dentry *dir; + struct dentry *d; + + dir = hard_iface->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_hardif() - delete the base directory for a hard interface * in debugfs. -- cgit v1.2.3