diff options
Diffstat (limited to 'security/tomoyo/tomoyo.c')
| -rw-r--r-- | security/tomoyo/tomoyo.c | 623 |
1 files changed, 623 insertions, 0 deletions
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c new file mode 100644 index 000000000000..04a92c3d65d4 --- /dev/null +++ b/security/tomoyo/tomoyo.c @@ -0,0 +1,623 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/tomoyo.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include <linux/lsm_hooks.h> +#include <uapi/linux/lsm.h> +#include "common.h" + +/** + * tomoyo_domain - Get "struct tomoyo_domain_info" for current thread. + * + * Returns pointer to "struct tomoyo_domain_info" for current thread. + */ +struct tomoyo_domain_info *tomoyo_domain(void) +{ + struct tomoyo_task *s = tomoyo_task(current); + + if (s->old_domain_info && !current->in_execve) { + atomic_dec(&s->old_domain_info->users); + s->old_domain_info = NULL; + } + return s->domain_info; +} + +/** + * 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) +{ + /* Restore old_domain_info saved by previous execve() request. */ + struct tomoyo_task *s = tomoyo_task(current); + + if (s->old_domain_info && !current->in_execve) { + atomic_dec(&s->domain_info->users); + s->domain_info = s->old_domain_info; + s->old_domain_info = NULL; + } + return 0; +} + +/** + * tomoyo_bprm_committed_creds - Target for security_bprm_committed_creds(). + * + * @bprm: Pointer to "struct linux_binprm". + */ +static void tomoyo_bprm_committed_creds(const struct linux_binprm *bprm) +{ + /* Clear old_domain_info saved by execve() request. */ + struct tomoyo_task *s = tomoyo_task(current); + + atomic_dec(&s->old_domain_info->users); + s->old_domain_info = NULL; +} + +#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER +/** + * tomoyo_bprm_creds_for_exec - Target for security_bprm_creds_for_exec(). + * + * @bprm: Pointer to "struct linux_binprm". + * + * Returns 0. + */ +static int tomoyo_bprm_creds_for_exec(struct linux_binprm *bprm) +{ + /* + * 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); + return 0; +} +#endif + +/** + * 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_task *s = tomoyo_task(current); + + /* + * Execute permission is checked against pathname passed to execve() + * using current domain. + */ + if (!s->old_domain_info) { + 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(s->domain_info, + &bprm->file->f_path, O_RDONLY); +} + +/** + * tomoyo_inode_getattr - Target for security_inode_getattr(). + * + * @path: Pointer to "struct path". + * + * 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_file_truncate - Target for security_file_truncate(). + * + * @file: Pointer to "struct file". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_file_truncate(struct file *file) +{ + return tomoyo_path_truncate(&file->f_path); +} + +/** + * 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". + * @flags: Rename options. + * + * 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, + const unsigned int flags) +{ + struct path path1 = { .mnt = old_parent->mnt, .dentry = old_dentry }; + struct path path2 = { .mnt = new_parent->mnt, .dentry = new_dentry }; + + if (flags & RENAME_EXCHANGE) { + const int err = tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path2, + &path1); + + if (err) + return err; + } + 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". + * + * Returns 0 on success, negative value otherwise. + */ +static int tomoyo_file_open(struct file *f) +{ + /* Don't check read permission here if called from execve(). */ + /* Illogically, FMODE_EXEC is in f_flags, not f_mode. */ + if (f->f_flags & __FMODE_EXEC) + return 0; + return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, + f->f_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_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. + * + * 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) +{ + 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); +} + +struct lsm_blob_sizes tomoyo_blob_sizes __ro_after_init = { + .lbs_task = sizeof(struct tomoyo_task), +}; + +/** + * tomoyo_task_alloc - Target for security_task_alloc(). + * + * @task: Pointer to "struct task_struct". + * @clone_flags: clone() flags. + * + * Returns 0. + */ +static int tomoyo_task_alloc(struct task_struct *task, + unsigned long clone_flags) +{ + struct tomoyo_task *old = tomoyo_task(current); + struct tomoyo_task *new = tomoyo_task(task); + + new->domain_info = old->domain_info; + atomic_inc(&new->domain_info->users); + new->old_domain_info = NULL; + return 0; +} + +/** + * tomoyo_task_free - Target for security_task_free(). + * + * @task: Pointer to "struct task_struct". + */ +static void tomoyo_task_free(struct task_struct *task) +{ + struct tomoyo_task *s = tomoyo_task(task); + + if (s->domain_info) { + atomic_dec(&s->domain_info->users); + s->domain_info = NULL; + } + if (s->old_domain_info) { + atomic_dec(&s->old_domain_info->users); + s->old_domain_info = NULL; + } +} + +static const struct lsm_id tomoyo_lsmid = { + .name = "tomoyo", + .id = LSM_ID_TOMOYO, +}; + +/* + * tomoyo_security_ops is a "struct security_operations" which is used for + * registering TOMOYO. + */ +static struct security_hook_list tomoyo_hooks[] __ro_after_init = { + LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare), + LSM_HOOK_INIT(bprm_committed_creds, tomoyo_bprm_committed_creds), + LSM_HOOK_INIT(task_alloc, tomoyo_task_alloc), + LSM_HOOK_INIT(task_free, tomoyo_task_free), +#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER + LSM_HOOK_INIT(bprm_creds_for_exec, tomoyo_bprm_creds_for_exec), +#endif + 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(file_truncate, tomoyo_file_truncate), + 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(file_ioctl_compat, 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_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); + +int tomoyo_enabled __ro_after_init = 1; + +/** + * tomoyo_init - Register TOMOYO Linux as a LSM module. + * + * Returns 0. + */ +static int __init tomoyo_init(void) +{ + struct tomoyo_task *s = tomoyo_task(current); + + /* register ourselves with the security framework */ + security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), + &tomoyo_lsmid); + pr_info("TOMOYO Linux initialized\n"); + s->domain_info = &tomoyo_kernel_domain; + atomic_inc(&tomoyo_kernel_domain.users); + s->old_domain_info = NULL; + tomoyo_mm_init(); + + return 0; +} + +DEFINE_LSM(tomoyo) = { + .name = "tomoyo", + .enabled = &tomoyo_enabled, + .flags = LSM_FLAG_LEGACY_MAJOR, + .blobs = &tomoyo_blob_sizes, + .init = tomoyo_init, +}; |