The tuntap driver allows an admin to create persistent devices and assign ownership of them to individual users. Unfortunately, relaxing the permissions on the /dev/net/tun device node so that they can actually use those devices will _also_ allow those users to create arbitrary new devices of their own. This patch corrects that, and adjusts the recommended permissions for the device node accordingly.
Signed-Off-By: David Woodhouse <[EMAIL PROTECTED]> diff --git a/Documentation/networking/tuntap.txt b/Documentation/networking/tuntap.txt index 76750fb..839cbb7 100644 --- a/Documentation/networking/tuntap.txt +++ b/Documentation/networking/tuntap.txt @@ -39,10 +39,13 @@ Copyright (C) 1999-2000 Maxim Krasnyansk mknod /dev/net/tun c 10 200 Set permissions: - e.g. chmod 0700 /dev/net/tun - if you want the device only accessible by root. Giving regular users the - right to assign network devices is NOT a good idea. Users could assign - bogus network interfaces to trick firewalls or administrators. + e.g. chmod 0666 /dev/net/tun + There's no harm in allowing the device to be accessible by non-root users, + since CAP_NET_ADMIN is required for creating network devices or for + connecting to network devices which aren't owned by the user in question. + If you want to create persistent devices and give ownership of them to + unprivileged users, then you need the /dev/net/tun device to be usable by + those users. Driver module autoloading diff --git a/drivers/net/tun.c b/drivers/net/tun.c index a1ed2d9..6c62d5c 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -490,6 +490,9 @@ static int tun_set_iff(struct file *file err = -EINVAL; + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + /* Set dev type */ if (ifr->ifr_flags & IFF_TUN) { /* TUN device */ -- dwmw2 - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html