--- /dev/null
+/*
+ * security/tomoyo/mount.c
+ *
+ * Copyright (C) 2005-2011 NTT DATA CORPORATION
+ */
+
+#include <linux/slab.h>
+#include "common.h"
+
+/* String table for special mount operations. */
+static const char * const tomoyo_mounts[TOMOYO_MAX_SPECIAL_MOUNT] = {
+ [TOMOYO_MOUNT_BIND] = "--bind",
+ [TOMOYO_MOUNT_MOVE] = "--move",
+ [TOMOYO_MOUNT_REMOUNT] = "--remount",
+ [TOMOYO_MOUNT_MAKE_UNBINDABLE] = "--make-unbindable",
+ [TOMOYO_MOUNT_MAKE_PRIVATE] = "--make-private",
+ [TOMOYO_MOUNT_MAKE_SLAVE] = "--make-slave",
+ [TOMOYO_MOUNT_MAKE_SHARED] = "--make-shared",
+};
+
+/**
+ * tomoyo_audit_mount_log - Audit mount log.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int tomoyo_audit_mount_log(struct tomoyo_request_info *r)
+{
+ return tomoyo_supervisor(r, "file mount %s %s %s 0x%lX\n",
+ r->param.mount.dev->name,
+ r->param.mount.dir->name,
+ r->param.mount.type->name,
+ r->param.mount.flags);
+}
+
+/**
+ * tomoyo_check_mount_acl - Check permission for path path path number operation.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ * @ptr: Pointer to "struct tomoyo_acl_info".
+ *
+ * Returns true if granted, false otherwise.
+ */
+static bool tomoyo_check_mount_acl(struct tomoyo_request_info *r,
+ const struct tomoyo_acl_info *ptr)
+{
+ const struct tomoyo_mount_acl *acl =
+ container_of(ptr, typeof(*acl), head);
+ return tomoyo_compare_number_union(r->param.mount.flags,
+ &acl->flags) &&
+ tomoyo_compare_name_union(r->param.mount.type,
+ &acl->fs_type) &&
+ tomoyo_compare_name_union(r->param.mount.dir,
+ &acl->dir_name) &&
+ (!r->param.mount.need_dev ||
+ tomoyo_compare_name_union(r->param.mount.dev,
+ &acl->dev_name));
+}
+
+/**
+ * tomoyo_mount_acl - Check permission for mount() operation.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ * @dev_name: Name of device file. Maybe NULL.
+ * @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,
+ const 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;
+
+ /* Get fstype. */
+ requested_type = tomoyo_encode(type);
+ if (!requested_type)
+ goto out;
+ rtype.name = requested_type;
+ tomoyo_fill_path_info(&rtype);
+
+ /* Get mount point. */
+ 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);
+
+ /* Compare fs name. */
+ if (type == tomoyo_mounts[TOMOYO_MOUNT_REMOUNT]) {
+ /* dev_name is ignored. */
+ } 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]) {
+ /* dev_name is ignored. */
+ } else if (type == tomoyo_mounts[TOMOYO_MOUNT_BIND] ||
+ type == tomoyo_mounts[TOMOYO_MOUNT_MOVE]) {
+ 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 (!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 {
+ /* 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);
+ /* Drop refcount obtained by kern_path(). */
+ if (obj.path1.dentry)
+ path_put(&obj.path1);
+ return error;
+}
+
+/**
+ * tomoyo_mount_permission - Check permission for mount() operation.
+ *
+ * @dev_name: Name of device file. Maybe NULL.
+ * @path: Pointer to "struct path".
+ * @type: Name of filesystem type. Maybe NULL.
+ * @flags: Mount options.
+ * @data_page: Optional data. Maybe NULL.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_mount_permission(const char *dev_name, struct path *path,
+ const char *type, unsigned long flags,
+ void *data_page)
+{
+ struct tomoyo_request_info r;
+ int error;
+ int idx;
+
+ if (tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_MOUNT)
+ == TOMOYO_CONFIG_DISABLED)
+ return 0;
+ if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
+ flags &= ~MS_MGC_MSK;
+ if (flags & MS_REMOUNT) {
+ type = tomoyo_mounts[TOMOYO_MOUNT_REMOUNT];
+ flags &= ~MS_REMOUNT;
+ } else if (flags & MS_BIND) {
+ type = tomoyo_mounts[TOMOYO_MOUNT_BIND];
+ flags &= ~MS_BIND;
+ } else if (flags & MS_SHARED) {
+ if (flags & (MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
+ return -EINVAL;
+ type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED];
+ flags &= ~MS_SHARED;
+ } else if (flags & MS_PRIVATE) {
+ if (flags & (MS_SHARED | MS_SLAVE | MS_UNBINDABLE))
+ return -EINVAL;
+ type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE];
+ flags &= ~MS_PRIVATE;
+ } else if (flags & MS_SLAVE) {
+ if (flags & (MS_SHARED | MS_PRIVATE | MS_UNBINDABLE))
+ return -EINVAL;
+ type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE];
+ flags &= ~MS_SLAVE;
+ } else if (flags & MS_UNBINDABLE) {
+ if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE))
+ return -EINVAL;
+ type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE];
+ flags &= ~MS_UNBINDABLE;
+ } else if (flags & MS_MOVE) {
+ type = tomoyo_mounts[TOMOYO_MOUNT_MOVE];
+ flags &= ~MS_MOVE;
+ }
+ if (!type)
+ type = "<NULL>";
+ idx = tomoyo_read_lock();
+ error = tomoyo_mount_acl(&r, dev_name, path, type, flags);
+ tomoyo_read_unlock(idx);
+ return error;
+}
Code Review / kvmfornfv.git / blobdiff