linux/fs/kernfs
Max Kellermann 952d0cbd1f fs/kernfs/dir: obey S_ISGID
[ Upstream commit 5133bee62f ]

Handling of S_ISGID is usually done by inode_init_owner() in all other
filesystems, but kernfs doesn't use that function.  In kernfs, struct
kernfs_node is the primary data structure, and struct inode is only
created from it on demand.  Therefore, inode_init_owner() can't be
used and we need to imitate its behavior.

S_ISGID support is useful for the cgroup filesystem; it allows
subtrees managed by an unprivileged process to retain a certain owner
gid, which then enables sharing access to the subtree with another
unprivileged process.

--
v1 -> v2: minor coding style fix (comment)

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231208093310.297233-2-max.kellermann@ionos.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:14:32 +00:00
..
dir.c fs/kernfs/dir: obey S_ISGID 2024-02-05 20:14:32 +00:00
file.c tty, proc, kernfs, random: Use copy_splice_read() 2023-05-24 08:42:16 -06:00
inode.c v6.6-vfs.tmpfs 2023-08-28 09:55:25 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
kernfs-internal.h kernfs: Use a per-fs rwsem to protect per-fs list of kernfs_super_info. 2023-03-29 12:23:45 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mount.c kernfs: attach uuid for every kernfs and report it in fsid 2023-08-05 08:32:39 +02:00
symlink.c kernfs: fix all kernel-doc warnings and multiple typos 2022-11-23 19:28:26 +01:00