brcompat_mod: Check if user has CAP_NET_ADMIN in ioctl handler

This patch checks that the user calling ioctl() to create, delete, or
modify bridges has the CAP_NET_ADMIN capability. This prevents
unpriviledged users from modifying the bridge configuration through
brcompatd. The checks are actually the same performed in
net/bridge/br_ioctl.c by the Linux kernel.

Signed-off-by: Vivien Bernet-Rollande <vbr@soprive.net>
Signed-off-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/brcompat.c b/datapath/brcompat.c
index 3e84011..2113eae 100644 (file)
--- a/datapath/brcompat.c
+++ b/datapath/brcompat.c
@@ -84,6 +84,9 @@ static int brc_add_del_bridge(char __user *uname, int add)
        struct sk_buff *request;
        char name[IFNAMSIZ];
 
+       if (!capable(CAP_NET_ADMIN))
+               return -EPERM;
+
        if (copy_from_user(name, uname, IFNAMSIZ))
                return -EFAULT;
 
@@ -196,6 +199,9 @@ static int brc_add_del_port(struct net_device *dev, int port_ifindex, int add)
        struct net_device *port;
        int err;
 
+       if (!capable(CAP_NET_ADMIN))
+               return -EPERM;
+
        port = __dev_get_by_index(&init_net, port_ifindex);
        if (!port)
                return -EINVAL;