[PATCH 5.10 50/77] net-sysfs: initialize uid and gid before calling net_ns_get_ownership

Greg Kroah-Hartman
2021-11-01T09:36:39Z

From: Xin Long <lucien.xin@gmail.com>

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>
---
net/core/net-sysfs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1957,9 +1957,9 @@ int netdev_register_kobject(struct net_d
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);