net-sysfs: initialize uid and gid before calling net_ns_get_ownership

commit f7a1e76d0f608961cc2fc681f867a834f2746bce upstream.

Currently in net_ns_get_ownership() it may not be able to set uid or gid
if make_kuid or make_kgid returns an invalid value, and an uninit-value
issue can be triggered by this.

This patch is to fix it by initializing the uid and gid before calling
net_ns_get_ownership(), as it does in kobject_get_ownership()

Fixes: e6dee9f3893c ("net-sysfs: add netdev_change_owner()")
Reported-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index b4562f9d074cf24081171261e112438195a57a39..cc5f760c78250e826b30c2bd11dbfbef1d7d92ae 100644 (file)
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1957,9 +1957,9 @@ int netdev_register_kobject(struct net_device *ndev)
 int netdev_change_owner(struct net_device *ndev, const struct net *net_old,
                        const struct net *net_new)
 {
+       kuid_t old_uid = GLOBAL_ROOT_UID, new_uid = GLOBAL_ROOT_UID;
+       kgid_t old_gid = GLOBAL_ROOT_GID, new_gid = GLOBAL_ROOT_GID;
        struct device *dev = &ndev->dev;
-       kuid_t old_uid, new_uid;
-       kgid_t old_gid, new_gid;
        int error;
 
        net_ns_get_ownership(net_old, &old_uid, &old_gid);