decnet: Do not build routes to devices without decnet private data.

[ Upstream commit a36a0d4008488fa545c74445d69eaf56377d5d4e ]

In particular, make sure we check for decnet private presence
for loopback devices.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 94f4ec0..bb516bb 100644 (file)
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -998,10 +998,13 @@ source_ok:
        if (!fld.daddr) {
                fld.daddr = fld.saddr;
 
-               err = -EADDRNOTAVAIL;
                if (dev_out)
                        dev_put(dev_out);
+               err = -EINVAL;
                dev_out = init_net.loopback_dev;
+               if (!dev_out->dn_ptr)
+                       goto out;
+               err = -EADDRNOTAVAIL;
                dev_hold(dev_out);
                if (!fld.daddr) {
                        fld.daddr =
@@ -1074,6 +1077,8 @@ source_ok:
                if (dev_out == NULL)
                        goto out;
                dn_db = rcu_dereference_raw(dev_out->dn_ptr);
+               if (!dn_db)
+                       goto e_inval;
                /* Possible improvement - check all devices for local addr */
                if (dn_dev_islocal(dev_out, fld.daddr)) {
                        dev_put(dev_out);
@@ -1115,6 +1120,8 @@ select_source:
                        dev_put(dev_out);
                dev_out = init_net.loopback_dev;
                dev_hold(dev_out);
+               if (!dev_out->dn_ptr)
+                       goto e_inval;
                fld.flowidn_oif = dev_out->ifindex;
                if (res.fi)
                        dn_fib_info_put(res.fi);