[PATCH v3] fs/proc/proc_sysctl.c: always initialize i_uid/i_gid

[Thomas Weißschuh]

Commit 5ec27ec735ba ("fs/proc/proc_sysctl.c: fix the default values of i_uid/i_gid on /proc/sys inodes.")
added defaults for i_uid/i_gid when set_ownership() is not implemented.
It missed to also adjust net_ctl_set_ownership() to use the same default
values in case the computation of a better value fails.

Instead always initialize i_uid/i_gid inside the sysfs core so
set_ownership() can safely skip setting them.

Fixes: 5ec27ec735ba ("fs/proc/proc_sysctl.c: fix the default values of i_uid/i_gid on /proc/sys inodes.")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
Changes in v3:
- Rebase onto v6.9-rc1
- Reword commit message and mention correct fixed commit
- Link to v2: https://lore.kernel.org/r/20240322-sysctl-net-ownership-v2-1-a8b4a3306542@xxxxxxxxxxxxxx

Changes in v2:
- Move the fallback logic to the sysctl core
- Link to v1: https://lore.kernel.org/r/20240315-sysctl-net-ownership-v1-1-2b465555a292@xxxxxxxxxxxxxx
---
 fs/proc/proc_sysctl.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 37cde0efee57..9e34ab9c21e4 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -479,12 +479,10 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
 			make_empty_dir_inode(inode);
 	}
 
+	inode->i_uid = GLOBAL_ROOT_UID;
+	inode->i_gid = GLOBAL_ROOT_GID;
 	if (root->set_ownership)
 		root->set_ownership(head, table, &inode->i_uid, &inode->i_gid);
-	else {
-		inode->i_uid = GLOBAL_ROOT_UID;
-		inode->i_gid = GLOBAL_ROOT_GID;
-	}
 
 	return inode;
 }

---
base-commit: 4cece764965020c22cff7665b18a012006359095
change-id: 20240315-sysctl-net-ownership-bc4e17eaeea6

Best regards,
-- 
Thomas Weißschuh <linux@xxxxxxxxxxxxxx>