[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/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 @@
err = -EINVAL;
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
/* Set dev type */
if (ifr->ifr_flags & IFF_TUN) {
/* TUN device */