rtnetlink: call validate_linkmsg in rtnl_create_link

BugLink: https://bugs.launchpad.net/bugs/2029808
commit b0ad3c179059089d809b477a1d445c1183a7b8fe upstream.

validate_linkmsg() was introduced by commit 1840bb13c22f5b ("[RTNL]:
Validate hardware and broadcast address attribute for RTM_NEWLINK")
to validate tb[IFLA_ADDRESS/BROADCAST] for existing links. The same
check should also be done for newly created links.

This patch adds validate_linkmsg() call in rtnl_create_link(), to
avoid the invalid address set when creating some devices like:

  # ip link add dummy0 type dummy
  # ip link add link dummy0 name mac0 address 01:02 type macsec

Fixes: 0e06877c6fdb ("[RTNETLINK]: rtnl_link: allow specifying initial device address")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index f5114b2395ae34ca36cb9cec64e79ecc06af0412..19784fbb11639118d1d332bf604a972f9e6746e6 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -3253,6 +3253,7 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname,
        struct net_device *dev;
        unsigned int num_tx_queues = 1;
        unsigned int num_rx_queues = 1;
+       int err;
 
        if (tb[IFLA_NUM_TX_QUEUES])
                num_tx_queues = nla_get_u32(tb[IFLA_NUM_TX_QUEUES]);
@@ -3288,13 +3289,18 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname,
        if (!dev)
                return ERR_PTR(-ENOMEM);
 
+       err = validate_linkmsg(dev, tb, extack);
+       if (err < 0) {
+               free_netdev(dev);
+               return ERR_PTR(err);
+       }
+
        dev_net_set(dev, net);
        dev->rtnl_link_ops = ops;
        dev->rtnl_link_state = RTNL_LINK_INITIALIZING;
 
        if (tb[IFLA_MTU]) {
                u32 mtu = nla_get_u32(tb[IFLA_MTU]);
-               int err;
 
                err = dev_validate_mtu(dev, mtu, extack);
                if (err) {