*/
int __mnt_want_write_file(struct file *file)
{
- struct inode *inode = file->f_dentry->d_inode;
+ struct inode *inode = file_inode(file);
if (!(file->f_mode & FMODE_WRITE) || special_file(inode->i_mode))
return __mnt_want_write(file->f_path.mnt);
return retval;
}
+/*
+ * Is the caller allowed to modify his namespace?
+ */
+static inline bool may_mount(void)
+{
+ return ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN);
+}
+
/*
* Now umount can handle mount points as well as block devices.
* This is important for filesystems which use unnamed block devices.
if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW))
return -EINVAL;
+ if (!may_mount())
+ return -EPERM;
+
if (!(flags & UMOUNT_NOFOLLOW))
lookup_flags |= LOOKUP_FOLLOW;
if (!check_mnt(mnt))
goto dput_and_out;
- retval = -EPERM;
- if (!ns_capable(mnt->mnt_ns->user_ns, CAP_SYS_ADMIN))
- goto dput_and_out;
-
retval = do_umount(mnt, flags);
dput_and_out:
/* we mustn't call path_put() as that would clear mnt_expiry_mark */
#endif
-static int mount_is_safe(struct path *path)
-{
- if (ns_capable(real_mount(path->mnt)->mnt_ns->user_ns, CAP_SYS_ADMIN))
- return 0;
- return -EPERM;
-#ifdef notyet
- if (S_ISLNK(path->dentry->d_inode->i_mode))
- return -EPERM;
- if (path->dentry->d_inode->i_mode & S_ISVTX) {
- if (current_uid() != path->dentry->d_inode->i_uid)
- return -EPERM;
- }
- if (inode_permission(path->dentry->d_inode, MAY_WRITE))
- return -EPERM;
- return 0;
-#endif
-}
-
static bool mnt_ns_loop(struct path *path)
{
/* Could bind mounting the mount namespace inode cause a
int type;
int err = 0;
- if (!ns_capable(mnt->mnt_ns->user_ns, CAP_SYS_ADMIN))
- return -EPERM;
-
if (path->dentry != path->mnt->mnt_root)
return -EINVAL;
LIST_HEAD(umount_list);
struct path old_path;
struct mount *mnt = NULL, *old;
- int err = mount_is_safe(path);
- if (err)
- return err;
+ int err;
if (!old_name || !*old_name)
return -EINVAL;
err = kern_path(old_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path);
struct super_block *sb = path->mnt->mnt_sb;
struct mount *mnt = real_mount(path->mnt);
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
if (!check_mnt(mnt))
return -EINVAL;
down_write(&sb->s_umount);
if (flags & MS_BIND)
err = change_mount_flags(path->mnt, flags);
+ else if (!capable(CAP_SYS_ADMIN))
+ err = -EPERM;
else
err = do_remount_sb(sb, flags, data, 0);
if (!err) {
struct path old_path, parent_path;
struct mount *p;
struct mount *old;
- int err = 0;
- if (!ns_capable(real_mount(path->mnt)->mnt_ns->user_ns, CAP_SYS_ADMIN))
- return -EPERM;
+ int err;
if (!old_name || !*old_name)
return -EINVAL;
err = kern_path(old_name, LOOKUP_FOLLOW, &old_path);
int mnt_flags, const char *name, void *data)
{
struct file_system_type *type;
- struct user_namespace *user_ns;
+ struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns;
struct vfsmount *mnt;
int err;
if (!fstype)
return -EINVAL;
- /* we need capabilities... */
- user_ns = real_mount(path->mnt)->mnt_ns->user_ns;
- if (!ns_capable(user_ns, CAP_SYS_ADMIN))
- return -EPERM;
-
type = get_fs_type(fstype);
if (!type)
return -ENODEV;
if (retval)
goto dput_out;
+ if (!may_mount())
+ return -EPERM;
+
/* Default to relatime unless overriden */
if (!(flags & MS_NOATIME))
mnt_flags |= MNT_RELATIME;
struct mount *new_mnt, *root_mnt;
int error;
- if (!ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN))
+ if (!may_mount())
return -EPERM;
error = user_path_dir(new_root, &new);