From: "Thomas Weißschuh" <linux@xxxxxxxxxxxxxx>
Date: Fri, 22 Mar 2024 20:51:11 +0100
> Commit e79c6a4fc923 ("net: make net namespace sysctls belong to container's owner")
> added default values for i_uid/i_gid.
The commit that added the default is 5ec27ec735ba ("fs/proc/proc_sysctl.c:
fix the default values of i_uid/i_gid on /proc/sys inodes.")
> These however are only used when ctl_table_root->set_ownership is not
> implemented.
> But the callbacks themselves could fail to compute i_uid/i_gid and they
> all need to have the same fallback logic for this case.
>
> This is unnecessary code duplication and prone to errors.
> For example net_ctl_set_ownership() missed the fallback.
>
> Instead always initialize i_uid/i_gid inside the sysfs core so
> set_ownership() can safely skip setting them.
>
> Fixes: e79c6a4fc923 ("net: make net namespace sysctls belong to container's owner")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Thomas Weißschuh <linux@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: ff9c18e435b042596c9d48badac7488e3fa76a55
> change-id: 20240315-sysctl-net-ownership-bc4e17eaeea6
>
> Best regards,
> --
> Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
