[TUN]: Fix RTNL-locking in tun/tap driver

Current tun/tap driver sets also net device's hw address when asked to
change character device's hw address. This is a good idea, but it
misses RTLN-locking, resulting following error message in 2.6.25-rc3's
inetdev_event() function:

RTNL: assertion failed at net/ipv4/devinet.c (1050)

Attached patch fixes this problem.

Signed-off-by: Kim B. Heino <Kim.Heino@bluegiga.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 038c1ef94d2e..7b816a032957 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -663,7 +663,11 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
         case SIOCSIFHWADDR:
         {
                 /* try to set the actual net device's hw address */
-                int ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
+                int ret;
+
+                rtnl_lock();
+                ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
+                rtnl_unlock();
 
                 if (ret == 0) {
                         /** Set the character device's hardware address. This is used when