[NET]: Require CAP_NET_ADMIN to create tuntap devices.
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 <dwmw2@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
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