br2684: allow assign only on a connected socket

The br2684 does not check if used vcc is in connected state,
causing potential Oops in pppoatm_send() when vcc->send() is called
on not fully connected socket.

Now br2684 can be assigned only on connected sockets; otherwise
-EINVAL error is returned.

Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index 6dc383c90262..403e71fa88fe 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -735,10 +735,13 @@ static int br2684_ioctl(struct socket *sock, unsigned int cmd,
                         return -ENOIOCTLCMD;
                 if (!capable(CAP_NET_ADMIN))
                         return -EPERM;
-                if (cmd == ATM_SETBACKEND)
+                if (cmd == ATM_SETBACKEND) {
+                        if (sock->state != SS_CONNECTED)
+                                return -EINVAL;
                         return br2684_regvcc(atmvcc, argp);
-                else
+                } else {
                         return br2684_create(argp);
+                }
 #ifdef CONFIG_ATM_BR2684_IPFILTER
         case BR2684_SETFILT:
                 if (atmvcc->push != br2684_push)