[34-longterm 108/260] tun: Don't add sysfs attributes to devices without sysfs directories

Paul Gortmaker
2011-01-02T07:54:41Z

From: Ben Hutchings <ben@decadent.org.uk>

This applies to 2.6.32 *only*. It has not been applied upstream since
the limitation no longer exists.

Prior to Linux 2.6.35, net devices outside the initial net namespace
did not have sysfs directories. Attempting to add attributes to
them will trigger a BUG().

Reported-and-tested-by: Russell Stuart <russell-debian@stuart.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/net/tun.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 4326520..7b4a88b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1061,7 +1061,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
if (err < 0)
goto err_free_sk;

- if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
+ if (!net_eq(dev_net(tun->dev), &init_net) ||
+ device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
device_create_file(&tun->dev->dev, &dev_attr_owner) ||
device_create_file(&tun->dev->dev, &dev_attr_group))
printk(KERN_ERR "Failed to create tun sysfs files\n");
--
1.7.3.3