From da279dac227a034595c99bb4294f951a08359640 Mon Sep 17 00:00:00 2001
From: Xin Long <lucien.xin@gmail.com>
Date: Mon, 25 Oct 2021 02:31:48 -0400
Subject: [PATCH] net-sysfs: initialize uid and gid before calling net_ns_get_ownership
Git-commit: f7a1e76d0f608961cc2fc681f867a834f2746bce
Patch-mainline: v5.15
References: stable-5.14.16

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

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

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index f6197774048b..b2e49eb7001d 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1973,9 +1973,9 @@ 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);
-- 
2.26.2