/* * security/tomoyo/tomoyo.c * * Copyright (C) 2005-2011 NTT DATA CORPORATION */ #include <linux/security.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) { int rc; rc = cap_bprm_set_creds(bprm); if (rc) return rc; /* * Do only if this function is called for the first time of an execve * operation. */ if (bprm->cred_prepared) 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(struct vfsmount *mnt, struct dentry *dentry) { struct path path = { mnt, dentry }; 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(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(struct path *parent, struct dentry *dentry) { struct path path = { parent->mnt, 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(struct path *parent, struct dentry *dentry, int mode) { struct path path = { parent->mnt, 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(struct path *parent, struct dentry *dentry) { struct path path = { parent->mnt, 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(struct path *parent, struct dentry *dentry, const char *old_name) { struct path path = { parent->mnt, 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(struct path *parent, struct dentry *dentry, int mode, unsigned int dev) { struct path path = { parent->mnt, 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, struct path *new_dir, struct dentry *new_dentry) { struct path path1 = { new_dir->mnt, old_dentry }; struct path path2 = { new_dir->mnt, 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(struct path *old_parent, struct dentry *old_dentry, struct path *new_parent, struct dentry *new_dentry) { struct path path1 = { old_parent->mnt, old_dentry }; struct path path2 = { new_parent->mnt, 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_dentry_open - Target for security_dentry_open(). * * @f: Pointer to "struct file". * @cred: Pointer to "struct cred". * * Returns 0 on success, negative value otherwise. */ static int tomoyo_dentry_open(struct file *f, const struct cred *cred) { 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(). * * @dentry: Pointer to "struct dentry". * @mnt: Pointer to "struct vfsmount". * @mode: DAC permission mode. * * Returns 0 on success, negative value otherwise. */ static int tomoyo_path_chmod(struct dentry *dentry, struct vfsmount *mnt, mode_t mode) { struct path path = { mnt, dentry }; 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(struct path *path, uid_t uid, gid_t gid) { int error = 0; if (uid != (uid_t) -1) error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path, uid); if (!error && gid != (gid_t) -1) error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path, 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(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(char *dev_name, struct path *path, 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->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(struct path *old_path, struct path *new_path) { return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path); } /* * tomoyo_security_ops is a "struct security_operations" which is used for * registering TOMOYO. */ static struct security_operations tomoyo_security_ops = { .name = "tomoyo", .cred_alloc_blank = tomoyo_cred_alloc_blank, .cred_prepare = tomoyo_cred_prepare, .cred_transfer = tomoyo_cred_transfer, .cred_free = tomoyo_cred_free, .bprm_set_creds = tomoyo_bprm_set_creds, .bprm_check_security = tomoyo_bprm_check_security, .file_fcntl = tomoyo_file_fcntl, .dentry_open = tomoyo_dentry_open, .path_truncate = tomoyo_path_truncate, .path_unlink = tomoyo_path_unlink, .path_mkdir = tomoyo_path_mkdir, .path_rmdir = tomoyo_path_rmdir, .path_symlink = tomoyo_path_symlink, .path_mknod = tomoyo_path_mknod, .path_link = tomoyo_path_link, .path_rename = tomoyo_path_rename, .inode_getattr = tomoyo_inode_getattr, .file_ioctl = tomoyo_file_ioctl, .path_chmod = tomoyo_path_chmod, .path_chown = tomoyo_path_chown, .path_chroot = tomoyo_path_chroot, .sb_mount = tomoyo_sb_mount, .sb_umount = tomoyo_sb_umount, .sb_pivotroot = tomoyo_sb_pivotroot, }; /* Lock for GC. */ struct srcu_struct 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_security_ops)) return 0; /* register ourselves with the security framework */ if (register_security(&tomoyo_security_ops) || init_srcu_struct(&tomoyo_ss)) panic("Failure registering TOMOYO Linux"); printk(KERN_INFO "TOMOYO Linux initialized\n"); cred->security = &tomoyo_kernel_domain; tomoyo_mm_init(); return 0; } security_initcall(tomoyo_init);