Yang Xu 0cb0093fd6 fs: add mode_strip_sgid() helper
commit 2b3416ceff5e6bd4922f6d1c61fb68113dd82302 upstream.

[remove userns argument of helper for 5.4.y backport]

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]
Link: https://lore.kernel.org/r/1657779088-2242-1-git-send-email-xuyang2018.jy@fujitsu.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-and-Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[commit 347750e1b69cef62966fbc5bd7dc579b4c00688a upstream
	backported from 5.10.y, resolved context conflicts]
Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 08:24:49 +01:00
..
2024-01-25 14:34:27 -08:00
2021-09-22 12:26:25 +02:00
2022-06-14 18:11:36 +02:00
2023-09-23 10:59:56 +02:00
2023-02-22 12:50:35 +01:00
2023-09-23 11:00:06 +02:00
2022-06-14 18:11:41 +02:00
2020-10-01 13:17:19 +02:00
2024-02-23 08:24:49 +01:00
2023-01-18 11:41:44 +01:00