macvlan: Fix one possible double free
[ Upstream commit d02fd6e7d2933ede6478a15f9e4ce8a93845824e ]
Because the macvlan_uninit would free the macvlan port, so there is one
double free case in macvlan_common_newlink. When the macvlan port is just
created, then register_netdevice or netdev_upper_dev_link failed and they
would invoke macvlan_uninit. Then it would reach the macvlan_port_destroy
which triggers the double free.
Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 6d55049..e8ad4d0 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1377,9 +1377,14 @@
return 0;
unregister_netdev:
+ /* macvlan_uninit would free the macvlan port */
unregister_netdevice(dev);
+ return err;
destroy_macvlan_port:
- if (create)
+ /* the macvlan port may be freed by macvlan_uninit when fail to register.
+ * so we destroy the macvlan port only when it's valid.
+ */
+ if (create && macvlan_port_get_rtnl(dev))
macvlan_port_destroy(port->dev);
return err;
}