2008-02-27 10:04:31

by Kim B. Heino

Subject: [PATCH] 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 <[email protected]>


--- 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

2008-02-29 20:26:38

by David Miller

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

From: "Kim B. Heino" <[email protected]>
Date: Wed, 27 Feb 2008 11:38:21 +0200

> 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 <[email protected]>

Applied, thanks.