[PATCH] fix RTNL-locking in tun/tap driver

Kim B. Heino
2008-02-27T10:04:31Z

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>

--- linux-2.6.25-rc3/drivers/net/tun.c.foo 2008-02-27 10:06:28.000000000 +0200
+++ linux-2.6.25-rc3/drivers/net/tun.c 2008-02-27 10:06:40.000000000 +0200
@@ -663,7 +663,11 @@ static int tun_chr_ioctl(struct inode *i
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