struct file_system_type *get_fs_type(const char *name)
{
struct file_system_type *fs;
const char *dot = strchr(name, '.');
int len = dot ? dot - name : strlen(name);
fs = __get_fs_type(name, len);
if (!fs && (request_module("%.*s", len, name) == 0))
fs = __get_fs_type(name, len);
if (dot && fs && !(fs->fs_flags & FS_HAS_SUBTYPE)) {
put_filesystem(fs);
fs = NULL;
}
return fs;
}
struct file_system_type *get_fs_type(const char *name)
{
struct file_system_type *fs;
const char *dot = strchr(name, '.');
int len = dot ? dot - name : strlen(name);
fs = __get_fs_type(name, len);
if (!fs && (request_module("fs-%.*s", len, name) == 0)) {
fs = __get_fs_type(name, len);
WARN_ONCE(!fs, "request_module fs-%.*s succeeded, but still no fs?\n", len, name);
}
if (dot && fs && !(fs->fs_flags & FS_HAS_SUBTYPE)) {
put_filesystem(fs);
fs = NULL;
}
return fs;
}
static int fs_name(unsigned int index, char __user * buf)
{
struct file_system_type * tmp;
int len, res;
read_lock(&file_systems_lock);
for (tmp = file_systems; tmp; tmp = tmp->next, index--)
if (index <= 0 && try_module_get(tmp->owner))
break;
read_unlock(&file_systems_lock);
if (!tmp)
return -EINVAL;
/* OK, we got the reference, so we can safely block */
len = strlen(tmp->name) + 1;
res = copy_to_user(buf, tmp->name, len) ? -EFAULT : 0;
put_filesystem(tmp);
return res;
}
/**
* put_fs_context - Dispose of a superblock configuration context.
* @fc: The context to dispose of.
*/
void put_fs_context(struct fs_context *fc)
{
struct super_block *sb;
if (fc->root) {
sb = fc->root->d_sb;
dput(fc->root);
fc->root = NULL;
deactivate_super(sb);
}
if (fc->need_free && fc->ops && fc->ops->free)
fc->ops->free(fc);
security_free_mnt_opts(&fc->security);
put_net(fc->net_ns);
put_user_ns(fc->user_ns);
put_cred(fc->cred);
kfree(fc->subtype);
put_fc_log(fc);
put_filesystem(fc->fs_type);
kfree(fc->source);
kfree(fc);
}
static int tomoyo_mount_acl(struct tomoyo_request_info *r, char *dev_name,
struct path *dir, const char *type,
unsigned long flags)
{
struct tomoyo_obj_info obj = { };
struct path path;
struct file_system_type *fstype = NULL;
const char *requested_type = NULL;
const char *requested_dir_name = NULL;
const char *requested_dev_name = NULL;
struct tomoyo_path_info rtype;
struct tomoyo_path_info rdev;
struct tomoyo_path_info rdir;
int need_dev = 0;
int error = -ENOMEM;
r->obj = &obj;
/* */
requested_type = tomoyo_encode(type);
if (!requested_type)
goto out;
rtype.name = requested_type;
tomoyo_fill_path_info(&rtype);
/* */
obj.path2 = *dir;
requested_dir_name = tomoyo_realpath_from_path(dir);
if (!requested_dir_name) {
error = -ENOMEM;
goto out;
}
rdir.name = requested_dir_name;
tomoyo_fill_path_info(&rdir);
/* */
if (type == tomoyo_mounts[TOMOYO_MOUNT_REMOUNT]) {
/* */
} else if (type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE] ||
type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE] ||
type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE] ||
type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED]) {
/* */
} else if (type == tomoyo_mounts[TOMOYO_MOUNT_BIND] ||
type == tomoyo_mounts[TOMOYO_MOUNT_MOVE]) {
need_dev = -1; /* */
} else {
fstype = get_fs_type(type);
if (!fstype) {
error = -ENODEV;
goto out;
}
if (fstype->fs_flags & FS_REQUIRES_DEV)
/* */
need_dev = 1;
}
if (need_dev) {
/* */
if (!dev_name || kern_path(dev_name, LOOKUP_FOLLOW, &path)) {
error = -ENOENT;
goto out;
}
obj.path1 = path;
requested_dev_name = tomoyo_realpath_from_path(&path);
if (!requested_dev_name) {
error = -ENOENT;
goto out;
}
} else {
/* */
if (!dev_name)
dev_name = "<NULL>";
requested_dev_name = tomoyo_encode(dev_name);
if (!requested_dev_name) {
error = -ENOMEM;
goto out;
}
}
rdev.name = requested_dev_name;
tomoyo_fill_path_info(&rdev);
r->param_type = TOMOYO_TYPE_MOUNT_ACL;
r->param.mount.need_dev = need_dev;
r->param.mount.dev = &rdev;
r->param.mount.dir = &rdir;
r->param.mount.type = &rtype;
r->param.mount.flags = flags;
do {
tomoyo_check_acl(r, tomoyo_check_mount_acl);
error = tomoyo_audit_mount_log(r);
} while (error == TOMOYO_RETRY_REQUEST);
out:
kfree(requested_dev_name);
kfree(requested_dir_name);
if (fstype)
put_filesystem(fstype);
kfree(requested_type);
/* */
if (obj.path1.dentry)
path_put(&obj.path1);
return error;
}
/**
* tomoyo_mount_acl - Check permission for mount() operation.
*
* @r: Pointer to "struct tomoyo_request_info".
* @dev_name: Name of device file.
* @dir: Pointer to "struct path".
* @type: Name of filesystem type.
* @flags: Mount options.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_mount_acl(struct tomoyo_request_info *r, char *dev_name,
struct path *dir, char *type, unsigned long flags)
{
struct path path;
struct file_system_type *fstype = NULL;
const char *requested_type = NULL;
const char *requested_dir_name = NULL;
const char *requested_dev_name = NULL;
struct tomoyo_path_info rtype;
struct tomoyo_path_info rdev;
struct tomoyo_path_info rdir;
int need_dev = 0;
int error = -ENOMEM;
/* Get fstype. */
requested_type = tomoyo_encode(type);
if (!requested_type)
goto out;
rtype.name = requested_type;
tomoyo_fill_path_info(&rtype);
/* Get mount point. */
requested_dir_name = tomoyo_realpath_from_path(dir);
if (!requested_dir_name) {
error = -ENOMEM;
goto out;
}
rdir.name = requested_dir_name;
tomoyo_fill_path_info(&rdir);
/* Compare fs name. */
if (!strcmp(type, TOMOYO_MOUNT_REMOUNT_KEYWORD)) {
/* dev_name is ignored. */
} else if (!strcmp(type, TOMOYO_MOUNT_MAKE_UNBINDABLE_KEYWORD) ||
!strcmp(type, TOMOYO_MOUNT_MAKE_PRIVATE_KEYWORD) ||
!strcmp(type, TOMOYO_MOUNT_MAKE_SLAVE_KEYWORD) ||
!strcmp(type, TOMOYO_MOUNT_MAKE_SHARED_KEYWORD)) {
/* dev_name is ignored. */
} else if (!strcmp(type, TOMOYO_MOUNT_BIND_KEYWORD) ||
!strcmp(type, TOMOYO_MOUNT_MOVE_KEYWORD)) {
need_dev = -1; /* dev_name is a directory */
} else {
fstype = get_fs_type(type);
if (!fstype) {
error = -ENODEV;
goto out;
}
if (fstype->fs_flags & FS_REQUIRES_DEV)
/* dev_name is a block device file. */
need_dev = 1;
}
if (need_dev) {
/* Get mount point or device file. */
if (kern_path(dev_name, LOOKUP_FOLLOW, &path)) {
error = -ENOENT;
goto out;
}
requested_dev_name = tomoyo_realpath_from_path(&path);
path_put(&path);
if (!requested_dev_name) {
error = -ENOENT;
goto out;
}
} else {
/* Map dev_name to "<NULL>" if no dev_name given. */
if (!dev_name)
dev_name = "<NULL>";
requested_dev_name = tomoyo_encode(dev_name);
if (!requested_dev_name) {
error = -ENOMEM;
goto out;
}
}
rdev.name = requested_dev_name;
tomoyo_fill_path_info(&rdev);
r->param_type = TOMOYO_TYPE_MOUNT_ACL;
r->param.mount.need_dev = need_dev;
r->param.mount.dev = &rdev;
r->param.mount.dir = &rdir;
r->param.mount.type = &rtype;
r->param.mount.flags = flags;
do {
tomoyo_check_acl(r, tomoyo_check_mount_acl);
error = tomoyo_audit_mount_log(r);
} while (error == TOMOYO_RETRY_REQUEST);
out:
kfree(requested_dev_name);
kfree(requested_dir_name);
if (fstype)
put_filesystem(fstype);
kfree(requested_type);
return error;
}
