Re: [RCF] [PATCH] unprivileged mount/umount

Miklos Szeredi
2005-05-13T09:11:05Z

> dentry = file->f_dentry;
> mnt = file->f_vfsmnt;
> inode = dentry->d_inode;
> + if(mnt->mnt_namespace != current->namespace)
> + goto out_putf;
>
> error = -ENOTDIR;
> if (!S_ISDIR(inode->i_mode))
>

Does this actually fix the problem? The open is done in the right
namespace, and mount() doesn't call open().

I think the right fix is something like this:

Index: linux/fs/namespace.c
===================================================================
--- linux.orig/fs/namespace.c 2005-05-13 11:03:50.000000000 +0200
+++ linux/fs/namespace.c 2005-05-13 11:05:06.000000000 +0200
@@ -160,7 +160,7 @@ clone_mnt(struct vfsmount *old, struct d
mnt->mnt_root = dget(root);
mnt->mnt_mountpoint = mnt->mnt_root;
mnt->mnt_parent = mnt;
- mnt->mnt_namespace = old->mnt_namespace;
+ mnt->mnt_namespace = current->namespace;

/* stick the duplicate mount on the same expiry list
* as the original if that was on one */