diff options
| author | NeilBrown <neil@brown.name> | 2025-11-13 11:18:29 +1100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-11-14 13:15:56 +0100 |
| commit | c9ba789dad15ba65662bba17595c0aeaa0cfcf1c (patch) | |
| tree | d6eaf6573d9222905a67f12a4015d9a85a47eeea /include/linux | |
| parent | bd6ede8a06e89ca5a94a8b51cea792705d1b8ca2 (diff) | |
VFS: introduce start_creating_noperm() and start_removing_noperm()
xfs, fuse, ipc/mqueue need variants of start_creating or start_removing
which do not check permissions.
This patch adds _noperm versions of these functions.
Note that do_mq_open() was only calling mntget() so it could call
path_put() - it didn't really need an extra reference on the mnt.
Now it doesn't call mntget() and uses end_creating() which does
the dput() half of path_put().
Also mq_unlink() previously passed
d_inode(dentry->d_parent)
as the dir inode to vfs_unlink(). This is after locking
d_inode(mnt->mnt_root)
These two inodes are the same, but normally calls use the textual
parent.
So I've changes the vfs_unlink() call to be given d_inode(mnt->mnt_root).
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neil@brown.name>
--
changes since v2:
- dir arg passed to vfs_unlink() in mq_unlink() changed to match
the dir passed to lookup_noperm()
- restore assignment to path->mnt even though the mntget() is removed.
Link: https://patch.msgid.link/20251113002050.676694-7-neilb@ownmail.net
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/namei.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/namei.h b/include/linux/namei.h index 9ee76e88f3dd..688e157d6afc 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -92,6 +92,8 @@ struct dentry *start_creating(struct mnt_idmap *idmap, struct dentry *parent, struct qstr *name); struct dentry *start_removing(struct mnt_idmap *idmap, struct dentry *parent, struct qstr *name); +struct dentry *start_creating_noperm(struct dentry *parent, struct qstr *name); +struct dentry *start_removing_noperm(struct dentry *parent, struct qstr *name); /** * end_creating - finish action started with start_creating |