blob: e1cf21e481ceb5dec26b084c14aeb0d4243cb5cb [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* security/tomoyo/tomoyo.c
*
* Copyright (C) 2005-2011 NTT DATA CORPORATION
*/
#include <linux/lsm_hooks.h>
#include "common.h"
/**
* tomoyo_cred_alloc_blank - Target for security_cred_alloc_blank().
*
* @new: Pointer to "struct cred".
* @gfp: Memory allocation flags.
*
* Returns 0.
*/
static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
{
new->security = NULL;
return 0;
}
/**
* tomoyo_cred_prepare - Target for security_prepare_creds().
*
* @new: Pointer to "struct cred".
* @old: Pointer to "struct cred".
* @gfp: Memory allocation flags.
*
* Returns 0.
*/
static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
gfp_t gfp)
{
struct tomoyo_domain_info *domain = old->security;
new->security = domain;
if (domain)
atomic_inc(&domain->users);
return 0;
}
/**
* tomoyo_cred_transfer - Target for security_transfer_creds().
*
* @new: Pointer to "struct cred".
* @old: Pointer to "struct cred".
*/
static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
{
tomoyo_cred_prepare(new, old, 0);
}
/**
* tomoyo_cred_free - Target for security_cred_free().
*
* @cred: Pointer to "struct cred".
*/
static void tomoyo_cred_free(struct cred *cred)
{
struct tomoyo_domain_info *domain = cred->security;
if (domain)
atomic_dec(&domain->users);
}
/**
* tomoyo_bprm_set_creds - Target for security_bprm_set_creds().
*
* @bprm: Pointer to "struct linux_binprm".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
{
/*
* Do only if this function is called for the first time of an execve
* operation.
*/
if (bprm->called_set_creds)
return 0;
#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
/*
* Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
* for the first time.
*/
if (!tomoyo_policy_loaded)
tomoyo_load_policy(bprm->filename);
#endif
/*
* Release reference to "struct tomoyo_domain_info" stored inside
* "bprm->cred->security". New reference to "struct tomoyo_domain_info"
* stored inside "bprm->cred->security" will be acquired later inside
* tomoyo_find_next_domain().
*/
atomic_dec(&((struct tomoyo_domain_info *)
bprm->cred->security)->users);
/*
* Tell tomoyo_bprm_check_security() is called for the first time of an
* execve operation.
*/
bprm->cred->security = NULL;
return 0;
}
/**
* tomoyo_bprm_check_security - Target for security_bprm_check().
*
* @bprm: Pointer to "struct linux_binprm".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
{
struct tomoyo_domain_info *domain = bprm->cred->security;
/*
* Execute permission is checked against pathname passed to do_execve()
* using current domain.
*/
if (!domain) {
const int idx = tomoyo_read_lock();
const int err = tomoyo_find_next_domain(bprm);
tomoyo_read_unlock(idx);
return err;
}
/*
* Read permission is checked against interpreters using next domain.
*/
return tomoyo_check_open_permission(domain, &bprm->file->f_path,
O_RDONLY);
}
/**
* tomoyo_inode_getattr - Target for security_inode_getattr().
*
* @mnt: Pointer to "struct vfsmount".
* @dentry: Pointer to "struct dentry".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_inode_getattr(const struct path *path)
{
return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, path, NULL);
}
/**
* tomoyo_path_truncate - Target for security_path_truncate().
*
* @path: Pointer to "struct path".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_truncate(const struct path *path)
{
return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL);
}
/**
* tomoyo_path_unlink - Target for security_path_unlink().
*
* @parent: Pointer to "struct path".
* @dentry: Pointer to "struct dentry".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_unlink(const struct path *parent, struct dentry *dentry)
{
struct path path = { .mnt = parent->mnt, .dentry = dentry };
return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL);
}
/**
* tomoyo_path_mkdir - Target for security_path_mkdir().
*
* @parent: Pointer to "struct path".
* @dentry: Pointer to "struct dentry".
* @mode: DAC permission mode.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_mkdir(const struct path *parent, struct dentry *dentry,
umode_t mode)
{
struct path path = { .mnt = parent->mnt, .dentry = dentry };
return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
mode & S_IALLUGO);
}
/**
* tomoyo_path_rmdir - Target for security_path_rmdir().
*
* @parent: Pointer to "struct path".
* @dentry: Pointer to "struct dentry".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_rmdir(const struct path *parent, struct dentry *dentry)
{
struct path path = { .mnt = parent->mnt, .dentry = dentry };
return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL);
}
/**
* tomoyo_path_symlink - Target for security_path_symlink().
*
* @parent: Pointer to "struct path".
* @dentry: Pointer to "struct dentry".
* @old_name: Symlink's content.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_symlink(const struct path *parent, struct dentry *dentry,
const char *old_name)
{
struct path path = { .mnt = parent->mnt, .dentry = dentry };
return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name);
}
/**
* tomoyo_path_mknod - Target for security_path_mknod().
*
* @parent: Pointer to "struct path".
* @dentry: Pointer to "struct dentry".
* @mode: DAC permission mode.
* @dev: Device attributes.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_mknod(const struct path *parent, struct dentry *dentry,
umode_t mode, unsigned int dev)
{
struct path path = { .mnt = parent->mnt, .dentry = dentry };
int type = TOMOYO_TYPE_CREATE;
const unsigned int perm = mode & S_IALLUGO;
switch (mode & S_IFMT) {
case S_IFCHR:
type = TOMOYO_TYPE_MKCHAR;
break;
case S_IFBLK:
type = TOMOYO_TYPE_MKBLOCK;
break;
default:
goto no_dev;
}
return tomoyo_mkdev_perm(type, &path, perm, dev);
no_dev:
switch (mode & S_IFMT) {
case S_IFIFO:
type = TOMOYO_TYPE_MKFIFO;
break;
case S_IFSOCK:
type = TOMOYO_TYPE_MKSOCK;
break;
}
return tomoyo_path_number_perm(type, &path, perm);
}
/**
* tomoyo_path_link - Target for security_path_link().
*
* @old_dentry: Pointer to "struct dentry".
* @new_dir: Pointer to "struct path".
* @new_dentry: Pointer to "struct dentry".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_link(struct dentry *old_dentry, const struct path *new_dir,
struct dentry *new_dentry)
{
struct path path1 = { .mnt = new_dir->mnt, .dentry = old_dentry };
struct path path2 = { .mnt = new_dir->mnt, .dentry = new_dentry };
return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
}
/**
* tomoyo_path_rename - Target for security_path_rename().
*
* @old_parent: Pointer to "struct path".
* @old_dentry: Pointer to "struct dentry".
* @new_parent: Pointer to "struct path".
* @new_dentry: Pointer to "struct dentry".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_rename(const struct path *old_parent,
struct dentry *old_dentry,
const struct path *new_parent,
struct dentry *new_dentry)
{
struct path path1 = { .mnt = old_parent->mnt, .dentry = old_dentry };
struct path path2 = { .mnt = new_parent->mnt, .dentry = new_dentry };
return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
}
/**
* tomoyo_file_fcntl - Target for security_file_fcntl().
*
* @file: Pointer to "struct file".
* @cmd: Command for fcntl().
* @arg: Argument for @cmd.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
unsigned long arg)
{
if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)))
return 0;
return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
O_WRONLY | (arg & O_APPEND));
}
/**
* tomoyo_file_open - Target for security_file_open().
*
* @f: Pointer to "struct file".
* @cred: Pointer to "struct cred".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_file_open(struct file *f)
{
int flags = f->f_flags;
/* Don't check read permission here if called from do_execve(). */
if (current->in_execve)
return 0;
return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
}
/**
* tomoyo_file_ioctl - Target for security_file_ioctl().
*
* @file: Pointer to "struct file".
* @cmd: Command for ioctl().
* @arg: Argument for @cmd.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
}
/**
* tomoyo_path_chmod - Target for security_path_chmod().
*
* @path: Pointer to "struct path".
* @mode: DAC permission mode.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_chmod(const struct path *path, umode_t mode)
{
return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path,
mode & S_IALLUGO);
}
/**
* tomoyo_path_chown - Target for security_path_chown().
*
* @path: Pointer to "struct path".
* @uid: Owner ID.
* @gid: Group ID.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
{
int error = 0;
if (uid_valid(uid))
error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path,
from_kuid(&init_user_ns, uid));
if (!error && gid_valid(gid))
error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path,
from_kgid(&init_user_ns, gid));
return error;
}
/**
* tomoyo_path_chroot - Target for security_path_chroot().
*
* @path: Pointer to "struct path".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_path_chroot(const struct path *path)
{
return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL);
}
/**
* tomoyo_sb_mount - Target for security_sb_mountpoint().
* @fc: Context describing the object to be mounted.
* @mountpoint: The target object to mount on.
* @mnt_flags: Mountpoint specific options (as MNT_* flags).
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_sb_mountpoint(struct fs_context *fc, struct path *mountpoint,
unsigned int mnt_flags)
{
return tomoyo_mount_permission_fc(fc, mountpoint, mnt_flags);
}
/**
* tomoyo_sb_mount - Target for security_sb_mount().
*
* @dev_name: Name of device file. Maybe NULL.
* @path: Pointer to "struct path".
* @type: Name of filesystem type. Maybe NULL.
* @flags: Mount options.
* @data: Optional data. Maybe NULL.
* @data_size: Size of data.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_sb_mount(const char *dev_name, const struct path *path,
const char *type, unsigned long flags,
void *data, size_t data_size)
{
return tomoyo_mount_permission(dev_name, path, type, flags, data);
}
/**
* tomoyo_sb_umount - Target for security_sb_umount().
*
* @mnt: Pointer to "struct vfsmount".
* @flags: Unmount options.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
{
struct path path = { .mnt = mnt, .dentry = mnt->mnt_root };
return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL);
}
/**
* tomoyo_sb_pivotroot - Target for security_sb_pivotroot().
*
* @old_path: Pointer to "struct path".
* @new_path: Pointer to "struct path".
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_sb_pivotroot(const struct path *old_path, const struct path *new_path)
{
return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
}
/**
* tomoyo_socket_listen - Check permission for listen().
*
* @sock: Pointer to "struct socket".
* @backlog: Backlog parameter.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_socket_listen(struct socket *sock, int backlog)
{
return tomoyo_socket_listen_permission(sock);
}
/**
* tomoyo_socket_connect - Check permission for connect().
*
* @sock: Pointer to "struct socket".
* @addr: Pointer to "struct sockaddr".
* @addr_len: Size of @addr.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_socket_connect(struct socket *sock, struct sockaddr *addr,
int addr_len)
{
return tomoyo_socket_connect_permission(sock, addr, addr_len);
}
/**
* tomoyo_socket_bind - Check permission for bind().
*
* @sock: Pointer to "struct socket".
* @addr: Pointer to "struct sockaddr".
* @addr_len: Size of @addr.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_socket_bind(struct socket *sock, struct sockaddr *addr,
int addr_len)
{
return tomoyo_socket_bind_permission(sock, addr, addr_len);
}
/**
* tomoyo_socket_sendmsg - Check permission for sendmsg().
*
* @sock: Pointer to "struct socket".
* @msg: Pointer to "struct msghdr".
* @size: Size of message.
*
* Returns 0 on success, negative value otherwise.
*/
static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg,
int size)
{
return tomoyo_socket_sendmsg_permission(sock, msg, size);
}
/*
* tomoyo_security_ops is a "struct security_operations" which is used for
* registering TOMOYO.
*/
static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(cred_alloc_blank, tomoyo_cred_alloc_blank),
LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare),
LSM_HOOK_INIT(cred_transfer, tomoyo_cred_transfer),
LSM_HOOK_INIT(cred_free, tomoyo_cred_free),
LSM_HOOK_INIT(bprm_set_creds, tomoyo_bprm_set_creds),
LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security),
LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl),
LSM_HOOK_INIT(file_open, tomoyo_file_open),
LSM_HOOK_INIT(path_truncate, tomoyo_path_truncate),
LSM_HOOK_INIT(path_unlink, tomoyo_path_unlink),
LSM_HOOK_INIT(path_mkdir, tomoyo_path_mkdir),
LSM_HOOK_INIT(path_rmdir, tomoyo_path_rmdir),
LSM_HOOK_INIT(path_symlink, tomoyo_path_symlink),
LSM_HOOK_INIT(path_mknod, tomoyo_path_mknod),
LSM_HOOK_INIT(path_link, tomoyo_path_link),
LSM_HOOK_INIT(path_rename, tomoyo_path_rename),
LSM_HOOK_INIT(inode_getattr, tomoyo_inode_getattr),
LSM_HOOK_INIT(file_ioctl, tomoyo_file_ioctl),
LSM_HOOK_INIT(path_chmod, tomoyo_path_chmod),
LSM_HOOK_INIT(path_chown, tomoyo_path_chown),
LSM_HOOK_INIT(path_chroot, tomoyo_path_chroot),
LSM_HOOK_INIT(sb_mountpoint, tomoyo_sb_mountpoint),
LSM_HOOK_INIT(sb_mount, tomoyo_sb_mount),
LSM_HOOK_INIT(sb_umount, tomoyo_sb_umount),
LSM_HOOK_INIT(sb_pivotroot, tomoyo_sb_pivotroot),
LSM_HOOK_INIT(socket_bind, tomoyo_socket_bind),
LSM_HOOK_INIT(socket_connect, tomoyo_socket_connect),
LSM_HOOK_INIT(socket_listen, tomoyo_socket_listen),
LSM_HOOK_INIT(socket_sendmsg, tomoyo_socket_sendmsg),
};
/* Lock for GC. */
DEFINE_SRCU(tomoyo_ss);
/**
* tomoyo_init - Register TOMOYO Linux as a LSM module.
*
* Returns 0.
*/
static int __init tomoyo_init(void)
{
struct cred *cred = (struct cred *) current_cred();
if (!security_module_enable("tomoyo"))
return 0;
/* register ourselves with the security framework */
security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
printk(KERN_INFO "TOMOYO Linux initialized\n");
cred->security = &tomoyo_kernel_domain;
tomoyo_mm_init();
return 0;
}
security_initcall(tomoyo_init);