Commit 6b03f7ed authored by Al Viro's avatar Al Viro
Browse files

path_connected(): pass mount and dentry separately 



eventually we'll want to do that check *before* mangling
nd->path.dentry...

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent c981a482

fs/namei.c

+5 −7
Original line number Diff line number Diff line
@@ -550,22 +550,20 @@ static int __nd_alloc_stack(struct nameidata *nd) 
}



/**

 * path_connected - Verify that a path->dentry is below path->mnt.mnt_root

 * @path: nameidate to verify

 * path_connected - Verify that a dentry is below mnt.mnt_root

 *

 * Rename can sometimes move a file or directory outside of a bind

 * mount, path_connected allows those cases to be detected.

 */

static bool path_connected(const struct path *path)

static bool path_connected(struct vfsmount *mnt, struct dentry *dentry)

{

	struct vfsmount *mnt = path->mnt;

	struct super_block *sb = mnt->mnt_sb;



	/* Bind mounts and multi-root filesystems can have disconnected paths */

	if (!(sb->s_iflags & SB_I_MULTIROOT) && (mnt->mnt_root == sb->s_root))

		return true;



	return is_subdir(path->dentry, mnt->mnt_root);

	return is_subdir(dentry, mnt->mnt_root);

}



static inline int nd_alloc_stack(struct nameidata *nd)
@@ -1386,7 +1384,7 @@ static int follow_dotdot_rcu(struct nameidata *nd) 
				return -ECHILD;

			nd->path.dentry = parent;

			nd->seq = seq;

			if (unlikely(!path_connected(&nd->path)))

			if (unlikely(!path_connected(nd->path.mnt, parent)))

				return -ECHILD;

			break;

		} else {
@@ -1448,7 +1446,7 @@ static int path_parent_directory(struct path *path) 
	/* rare case of legitimate dget_parent()... */

	path->dentry = dget_parent(path->dentry);

	dput(old);

	if (unlikely(!path_connected(path)))

	if (unlikely(!path_connected(path->mnt, path->dentry)))

		return -ENOENT;

	return 0;

}