On Thu, Jul 14, 2022 at 02:11:25PM +0800, Yang Xu wrote:
> Add a dedicated helper to handle the setgid bit when creating a new file
> in a setgid directory. This is a preparatory patch for moving setgid
> stripping into the vfs. The patch contains no functional changes.
>
> Currently the setgid stripping logic is open-coded directly in
> inode_init_owner() and the individual filesystems are responsible for
> handling setgid inheritance. Since this has proven to be brittle as
> evidenced by old issues we uncovered over the last months (see [1] to
> [3] below) we will try to move this logic into the vfs.
>
> Link: e014f37db1a2 ("xfs: use setattr_copy to set vfs inode attributes") [1]
> Link: 01ea173e103e ("xfs: fix up non-directory creation in SGID directories") [2]
> Link: fd84bfdddd16 ("ceph: fix up non-directory creation in SGID directories") [3]
> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> Reviewed-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
> Reviewed-and-Tested-by: Jeff Layton <jlayton@xxxxxxxxxx>
> Signed-off-by: Yang Xu <xuyang2018.jy@xxxxxxxxxxx>
> ---
Fyi, I'm on vacation this week and will review this when I get back and
if things look sane plan to pick it up for the next mw.
Christian
