security/tomoyo/mount.c - linux - Git at Google

 /*
  * security/tomoyo/mount.c
  *
  * Copyright (C) 2005-2010  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)
 {
 	const char *dev = r->param.mount.dev->name;
 	const char *dir = r->param.mount.dir->name;
 	const char *type = r->param.mount.type->name;
 	const unsigned long flags = r->param.mount.flags;
 	if (r->granted)
 		return 0;
 	if (type == tomoyo_mounts[TOMOYO_MOUNT_REMOUNT])
 		tomoyo_warn_log(r, "mount -o remount %s 0x%lX", dir, flags);
 	else if (type == tomoyo_mounts[TOMOYO_MOUNT_BIND]
 		 || type == tomoyo_mounts[TOMOYO_MOUNT_MOVE])
 		tomoyo_warn_log(r, "mount %s %s %s 0x%lX", type, dev, dir,
 				flags);
 	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])
 		tomoyo_warn_log(r, "mount %s %s 0x%lX", type, dir, flags);
 	else
 		tomoyo_warn_log(r, "mount -t %s %s %s 0x%lX", type, dev, dir,
 				flags);
 	return tomoyo_supervisor(r, "allow_mount %s %s %s 0x%lX\n",
 				 r->param.mount.dev->name,
 				 r->param.mount.dir->name, type, 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.
  * @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, const 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 (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 (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;
 }

 /**
  * tomoyo_mount_permission - Check permission for mount() operation.
  *
  * @dev_name:  Name of device file.
  * @path:      Pointer to "struct path".
  * @type:      Name of filesystem type. May be NULL.
  * @flags:     Mount options.
  * @data_page: Optional data. May be NULL.
  *
  * Returns 0 on success, negative value otherwise.
  */
 int tomoyo_mount_permission(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;
 	}
 	if (flags & MS_MOVE) {
 		type = tomoyo_mounts[TOMOYO_MOUNT_MOVE];
 		flags &= ~MS_MOVE;
 	}
 	if (flags & MS_BIND) {
 		type = tomoyo_mounts[TOMOYO_MOUNT_BIND];
 		flags &= ~MS_BIND;
 	}
 	if (flags & MS_UNBINDABLE) {
 		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE];
 		flags &= ~MS_UNBINDABLE;
 	}
 	if (flags & MS_PRIVATE) {
 		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE];
 		flags &= ~MS_PRIVATE;
 	}
 	if (flags & MS_SLAVE) {
 		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE];
 		flags &= ~MS_SLAVE;
 	}
 	if (flags & MS_SHARED) {
 		type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED];
 		flags &= ~MS_SHARED;
 	}
 	if (!type)
 		type = "<NULL>";
 	idx = tomoyo_read_lock();
 	error = tomoyo_mount_acl(&r, dev_name, path, type, flags);
 	tomoyo_read_unlock(idx);
 	return error;
 }

 /**
  * tomoyo_same_mount_acl - Check for duplicated "struct tomoyo_mount_acl" entry.
  *
  * @a: Pointer to "struct tomoyo_acl_info".
  * @b: Pointer to "struct tomoyo_acl_info".
  *
  * Returns true if @a == @b, false otherwise.
  */
 static bool tomoyo_same_mount_acl(const struct tomoyo_acl_info *a,
 				  const struct tomoyo_acl_info *b)
 {
 	const struct tomoyo_mount_acl *p1 = container_of(a, typeof(*p1), head);
 	const struct tomoyo_mount_acl *p2 = container_of(b, typeof(*p2), head);
 	return tomoyo_same_name_union(&p1->dev_name, &p2->dev_name) &&
 		tomoyo_same_name_union(&p1->dir_name, &p2->dir_name) &&
 		tomoyo_same_name_union(&p1->fs_type, &p2->fs_type) &&
 		tomoyo_same_number_union(&p1->flags, &p2->flags);
 }

 /**
  * tomoyo_write_mount - Write "struct tomoyo_mount_acl" list.
  *
  * @data:      String to parse.
  * @domain:    Pointer to "struct tomoyo_domain_info".
  * @is_delete: True if it is a delete request.
  *
  * Returns 0 on success, negative value otherwise.
  *
  * Caller holds tomoyo_read_lock().
  */
 int tomoyo_write_mount(char *data, struct tomoyo_domain_info *domain,
 		       const bool is_delete)
 {
 	struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL };
 	int error = is_delete ? -ENOENT : -ENOMEM;
 	char *w[4];
 	if (!tomoyo_tokenize(data, w, sizeof(w)) || !w[3][0])
 		return -EINVAL;
 	if (!tomoyo_parse_name_union(w[0], &e.dev_name) ||
 	    !tomoyo_parse_name_union(w[1], &e.dir_name) ||
 	    !tomoyo_parse_name_union(w[2], &e.fs_type) ||
 	    !tomoyo_parse_number_union(w[3], &e.flags))
 		goto out;
 	error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
 				     tomoyo_same_mount_acl, NULL);
  out:
 	tomoyo_put_name_union(&e.dev_name);
 	tomoyo_put_name_union(&e.dir_name);
 	tomoyo_put_name_union(&e.fs_type);
 	tomoyo_put_number_union(&e.flags);
 	return error;
 }
	/*
	* security/tomoyo/mount.c
	*
	* Copyright (C) 2005-2010 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)
	{
	const char *dev = r->param.mount.dev->name;
	const char *dir = r->param.mount.dir->name;
	const char *type = r->param.mount.type->name;
	const unsigned long flags = r->param.mount.flags;
	if (r->granted)
	return 0;
	if (type == tomoyo_mounts[TOMOYO_MOUNT_REMOUNT])
	tomoyo_warn_log(r, "mount -o remount %s 0x%lX", dir, flags);
	else if (type == tomoyo_mounts[TOMOYO_MOUNT_BIND]
	\|\| type == tomoyo_mounts[TOMOYO_MOUNT_MOVE])
	tomoyo_warn_log(r, "mount %s %s %s 0x%lX", type, dev, dir,
	flags);
	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])
	tomoyo_warn_log(r, "mount %s %s 0x%lX", type, dir, flags);
	else
	tomoyo_warn_log(r, "mount -t %s %s %s 0x%lX", type, dev, dir,
	flags);
	return tomoyo_supervisor(r, "allow_mount %s %s %s 0x%lX\n",
	r->param.mount.dev->name,
	r->param.mount.dir->name, type, 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.
	* @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, const 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 (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 (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;
	}

	/**
	* tomoyo_mount_permission - Check permission for mount() operation.
	*
	* @dev_name: Name of device file.
	* @path: Pointer to "struct path".
	* @type: Name of filesystem type. May be NULL.
	* @flags: Mount options.
	* @data_page: Optional data. May be NULL.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	int tomoyo_mount_permission(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;
	}
	if (flags & MS_MOVE) {
	type = tomoyo_mounts[TOMOYO_MOUNT_MOVE];
	flags &= ~MS_MOVE;
	}
	if (flags & MS_BIND) {
	type = tomoyo_mounts[TOMOYO_MOUNT_BIND];
	flags &= ~MS_BIND;
	}
	if (flags & MS_UNBINDABLE) {
	type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE];
	flags &= ~MS_UNBINDABLE;
	}
	if (flags & MS_PRIVATE) {
	type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE];
	flags &= ~MS_PRIVATE;
	}
	if (flags & MS_SLAVE) {
	type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE];
	flags &= ~MS_SLAVE;
	}
	if (flags & MS_SHARED) {
	type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED];
	flags &= ~MS_SHARED;
	}
	if (!type)
	type = "<NULL>";
	idx = tomoyo_read_lock();
	error = tomoyo_mount_acl(&r, dev_name, path, type, flags);
	tomoyo_read_unlock(idx);
	return error;
	}

	/**
	* tomoyo_same_mount_acl - Check for duplicated "struct tomoyo_mount_acl" entry.
	*
	* @a: Pointer to "struct tomoyo_acl_info".
	* @b: Pointer to "struct tomoyo_acl_info".
	*
	* Returns true if @a == @b, false otherwise.
	*/
	static bool tomoyo_same_mount_acl(const struct tomoyo_acl_info *a,
	const struct tomoyo_acl_info *b)
	{
	const struct tomoyo_mount_acl p1 = container_of(a, typeof(p1), head);
	const struct tomoyo_mount_acl p2 = container_of(b, typeof(p2), head);
	return tomoyo_same_name_union(&p1->dev_name, &p2->dev_name) &&
	tomoyo_same_name_union(&p1->dir_name, &p2->dir_name) &&
	tomoyo_same_name_union(&p1->fs_type, &p2->fs_type) &&
	tomoyo_same_number_union(&p1->flags, &p2->flags);
	}

	/**
	* tomoyo_write_mount - Write "struct tomoyo_mount_acl" list.
	*
	* @data: String to parse.
	* @domain: Pointer to "struct tomoyo_domain_info".
	* @is_delete: True if it is a delete request.
	*
	* Returns 0 on success, negative value otherwise.
	*
	* Caller holds tomoyo_read_lock().
	*/
	int tomoyo_write_mount(char data, struct tomoyo_domain_info domain,
	const bool is_delete)
	{
	struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL };
	int error = is_delete ? -ENOENT : -ENOMEM;
	char *w[4];
	if (!tomoyo_tokenize(data, w, sizeof(w)) \|\| !w[3][0])
	return -EINVAL;
	if (!tomoyo_parse_name_union(w[0], &e.dev_name) \|\|
	!tomoyo_parse_name_union(w[1], &e.dir_name) \|\|
	!tomoyo_parse_name_union(w[2], &e.fs_type) \|\|
	!tomoyo_parse_number_union(w[3], &e.flags))
	goto out;
	error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
	tomoyo_same_mount_acl, NULL);
	out:
	tomoyo_put_name_union(&e.dev_name);
	tomoyo_put_name_union(&e.dir_name);
	tomoyo_put_name_union(&e.fs_type);
	tomoyo_put_number_union(&e.flags);
	return error;
	}