[RFC v2 1/2] WhiteEgret: Add WhiteEgret core functions.
masanobu2.koike at toshiba.co.jp
masanobu2.koike at toshiba.co.jp
Fri Mar 2 03:57:19 UTC 2018
On Friday, March 02, 2018 12:43 AM, Casey Schaufler wrote:
> On 2/28/2018 11:38 PM, Masanobu Koike wrote:
> > This RFC provides implementation of WhiteEgret.
> >
> > Signed-off-by: Masanobu Koike <masanobu2.koike at toshiba.co.jp>
> > ---
> > security/Kconfig | 6 +
> > security/Makefile | 2 +
> > security/whiteegret/Kconfig | 11 ++
> > security/whiteegret/Makefile | 2 +
> > security/whiteegret/init.c | 75 ++++++++++
> > security/whiteegret/main.c | 251
> +++++++++++++++++++++++++++++++++
> > security/whiteegret/request.c | 151 ++++++++++++++++++++
> > security/whiteegret/request.h | 52 +++++++
> > security/whiteegret/we.h | 66 +++++++++
> > security/whiteegret/we_fs.c | 280
> +++++++++++++++++++++++++++++++++++++
> > security/whiteegret/we_fs.h | 23 +++
> > security/whiteegret/we_fs_common.h | 36 +++++
> > 12 files changed, 955 insertions(+)
> > create mode 100644 security/whiteegret/Kconfig
> > create mode 100644 security/whiteegret/Makefile
> > create mode 100644 security/whiteegret/init.c
> > create mode 100644 security/whiteegret/main.c
> > create mode 100644 security/whiteegret/request.c
> > create mode 100644 security/whiteegret/request.h
> > create mode 100644 security/whiteegret/we.h
> > create mode 100644 security/whiteegret/we_fs.c
> > create mode 100644 security/whiteegret/we_fs.h
> > create mode 100644 security/whiteegret/we_fs_common.h
> >
> > diff --git a/security/Kconfig b/security/Kconfig
> > index c4302067a3ad..f17fefecaf84 100644
> > --- a/security/Kconfig
> > +++ b/security/Kconfig
> > @@ -237,6 +237,7 @@ source security/tomoyo/Kconfig
> > source security/apparmor/Kconfig
> > source security/loadpin/Kconfig
> > source security/yama/Kconfig
> > +source security/whiteegret/Kconfig
> >
> > source security/integrity/Kconfig
> >
> > @@ -246,6 +247,7 @@ choice
> > default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
> > default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
> > default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
> > + default DEFAULT_SECURITY_WHITEEGRET if SECURITY_WHITEEGRET
> > default DEFAULT_SECURITY_DAC
> >
> > help
> > @@ -264,6 +266,9 @@ choice
> > config DEFAULT_SECURITY_APPARMOR
> > bool "AppArmor" if SECURITY_APPARMOR=y
> >
> > + config DEFAULT_SECURITY_WHITEEGRET
> > + bool "WhiteEgret" if SECURITY_WHITEEGRET=y
> > +
>
> I don't see this module using any security blobs. Is there
> a reason you're not making this a minor (like yama) module
> instead of a major (like AppArmor) module?
Thank you for your suggestion.
We are now developing WhiteEgret on the environment
it works certainly.
Masanobu Koike
>
> > config DEFAULT_SECURITY_DAC
> > bool "Unix Discretionary Access Controls"
> >
> > @@ -275,6 +280,7 @@ config DEFAULT_SECURITY
> > default "smack" if DEFAULT_SECURITY_SMACK
> > default "tomoyo" if DEFAULT_SECURITY_TOMOYO
> > default "apparmor" if DEFAULT_SECURITY_APPARMOR
> > + default "whiteegret" if DEFAULT_SECURITY_WHITEEGRET
> > default "" if DEFAULT_SECURITY_DAC
> >
> > endmenu
> > diff --git a/security/Makefile b/security/Makefile
> > index 4d2d3782ddef..3a8249c77288 100644
> > --- a/security/Makefile
> > +++ b/security/Makefile
> > @@ -10,6 +10,7 @@ subdir-$(CONFIG_SECURITY_TOMOYO) += tomoyo
> > subdir-$(CONFIG_SECURITY_APPARMOR) += apparmor
> > subdir-$(CONFIG_SECURITY_YAMA) += yama
> > subdir-$(CONFIG_SECURITY_LOADPIN) += loadpin
> > +subdir-$(CONFIG_SECURITY_WHITEEGRET) += whiteegret
> >
> > # always enable default capabilities
> > obj-y += commoncap.o
> > @@ -25,6 +26,7 @@ obj-$(CONFIG_SECURITY_TOMOYO) +=
> tomoyo/
> > obj-$(CONFIG_SECURITY_APPARMOR) += apparmor/
> > obj-$(CONFIG_SECURITY_YAMA) += yama/
> > obj-$(CONFIG_SECURITY_LOADPIN) += loadpin/
> > +obj-$(CONFIG_SECURITY_WHITEEGRET) += whiteegret/
> > obj-$(CONFIG_CGROUP_DEVICE) += device_cgroup.o
> >
> > # Object integrity file lists
> > diff --git a/security/whiteegret/Kconfig b/security/whiteegret/Kconfig
> > new file mode 100644
> > index 000000000000..32845977745f
> > --- /dev/null
> > +++ b/security/whiteegret/Kconfig
> > @@ -0,0 +1,11 @@
> > +config SECURITY_WHITEEGRET
> > + bool "WhiteEgret support"
> > + depends on SECURITY
> > + default n
> > + help
> > + This enables the WhiteEgret security module.
> > + WhiteEgret provides a whitelisting execution control
> capability,
> > + which helps stop the execution of unauthorized software
> > + such as malware.
> > + You will also need a user application and an execution whitelist.
> > + If you are unsure how to answer this question, answer N.
> > diff --git a/security/whiteegret/Makefile
> b/security/whiteegret/Makefile
> > new file mode 100644
> > index 000000000000..16bd3afd9324
> > --- /dev/null
> > +++ b/security/whiteegret/Makefile
> > @@ -0,0 +1,2 @@
> > +obj-$(CONFIG_SECURITY_WHITEEGRET) += whiteegret.o
> > +whiteegret-y := init.o main.o request.o we_fs.o
> > diff --git a/security/whiteegret/init.c b/security/whiteegret/init.c
> > new file mode 100644
> > index 000000000000..3691cca6bc27
> > --- /dev/null
> > +++ b/security/whiteegret/init.c
> > @@ -0,0 +1,75 @@
> > +/*
> > + * WhiteEgret Linux Security Module
> > + *
> > + * Copyright (C) 2017-2018 Toshiba Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation, version 2.
> > + */
> > +
> > +#define pr_fmt(fmt) "WhiteEgret: " fmt
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/sched.h>
> > +#include <linux/security.h>
> > +#include <linux/fs.h>
> > +#include "we.h"
> > +
> > +#include <linux/lsm_hooks.h>
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("WhiteEgret Linux Security Module");
> > +
> > +static int we_security_bprm_check(struct linux_binprm *bprm)
> > +{
> > + if (we_security_bprm_check_main(bprm) == -EACCES)
> > + return -EACCES;
> > +
> > + return 0;
> > +}
> > +
> > +static int we_security_mmap_check(struct file *file, unsigned long
> reqprot,
> > + unsigned long prot, unsigned long flags)
> > +{
> > + if (we_security_mmap_check_main(file, reqprot, flags) == -EACCES)
> > + return -EACCES;
> > +
> > + return 0;
> > +}
> > +
> > +static struct security_hook_list we_hooks[] = {
> > + LSM_HOOK_INIT(bprm_check_security, we_security_bprm_check),
> > + LSM_HOOK_INIT(mmap_file, we_security_mmap_check),
> > +};
> > +
> > +static int __init we_init(void)
> > +{
> > + int rc;
> > +
> > + if (!security_module_enable("whiteegret"))
> > + return 0;
> > +
> > + security_add_hooks(we_hooks, ARRAY_SIZE(we_hooks),
> "whiteegret");
> > +
> > + rc = we_specific_init();
> > + if (rc) {
> > + pr_err("error %d at %d in %s\n", rc, __LINE__, __FILE__);
> > + return rc;
> > + }
> > +
> > + pr_warn("WhiteEgret (LSM) initialized.\n");
> > +
> > + return 0;
> > +}
> > +
> > +static void __exit we_exit(void)
> > +{
> > + we_specific_exit();
> > +
> > + pr_warn("WhiteEgret (LSM) exited.\n");
> > +}
> > +
> > +module_init(we_init);
> > +module_exit(we_exit);
> > diff --git a/security/whiteegret/main.c b/security/whiteegret/main.c
> > new file mode 100644
> > index 000000000000..f60e1d325011
> > --- /dev/null
> > +++ b/security/whiteegret/main.c
> > @@ -0,0 +1,251 @@
> > +/*
> > + * WhiteEgret Linux Security Module
> > + *
> > + * Copyright (C) 2017-2018 Toshiba Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation, version 2.
> > + */
> > +
> > +#define pr_fmt(fmt) "WhiteEgret: " fmt
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/semaphore.h>
> > +#include <linux/binfmts.h>
> > +#include <linux/dcache.h>
> > +#include <linux/fs.h>
> > +#include <linux/mman.h>
> > +#include "we.h"
> > +#include "request.h"
> > +
> > +#include <linux/sched.h>
> > +#include <linux/module.h>
> > +#include <linux/slab.h>
> > +#include "we_fs.h"
> > +
> > +
> > +static int send_receive_we_obj_info(
> > + struct we_obj_info *we_obj_info, int *checkresult);
> > +
> > +/**
> > + * we_specific_init - Initialize fs.
> > + *
> > + * Returns 0.
> > + */
> > +int we_specific_init(void)
> > +{
> > + int rc = 0;
> > +
> > + rc = we_fs_init();
> > + if (rc < 0) {
> > + pr_err("error %d at %d in %s\n", rc, __LINE__, __FILE__);
> > + return rc;
> > + }
> > +
> > + we_req_q_head_init();
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * we_specific_exit - Nothing to do in the implementation.
> > + *
> > + * Returns 0.
> > + */
> > +int we_specific_exit(void)
> > +{
> > + return 0;
> > +}
> > +
> > +/**
> > + * we_check_main - Common function for security_bprm_check and mmap_file.
> > + *
> > + * @file: Pointer to struct file.
> > + *
> > + * Returns 0 if succeeded, < 0 otherwise.
> > + */
> > +int we_check_main(struct file *file)
> > +{
> > + struct inode *inode;
> > + struct we_obj_info we_obj_info;
> > + char *pathnamebuf;
> > + char *new_pathnamebuf;
> > + char *pathname;
> > + char *shortnamebuf;
> > + int pathsize;
> > + int rc;
> > + int i;
> > + int checkresult;
> > +
> > + if (unlikely(file == NULL))
> > + return 0;
> > +
> > + pathsize = EXPECTPATHSIZE;
> > + pathnamebuf = kmalloc(pathsize, GFP_KERNEL);
> > + if (unlikely(!pathnamebuf)) {
> > + rc = -ENOMEM;
> > + pr_err("error %d at %d in %s\n", rc, __LINE__, __FILE__);
> > + goto failure;
> > + }
> > + while (pathsize <= MAXPATHSIZE) {
> > + pathname = d_absolute_path(&file->f_path, pathnamebuf,
> > + pathsize-1);
> > + if (!IS_ERR(pathname))
> > + break;
> > +
> > + pathsize += ADDEDEXPECTPATHSIZE;
> > + new_pathnamebuf = krealloc(pathnamebuf, pathsize,
> > + GFP_KERNEL);
> > + if (unlikely(!new_pathnamebuf)) {
> > + rc = -ENOMEM;
> > + pr_err("error %d at %d in %s\n", rc,
> > + __LINE__, __FILE__);
> > + goto failure;
> > + }
> > + pathnamebuf = new_pathnamebuf;
> > + }
> > + if (unlikely(pathsize >= MAXPATHSIZE)) {
> > + rc = -ENOMEM;
> > + pr_err("error %d at %d in %s\n", rc, __LINE__, __FILE__);
> > + goto failure;
> > + }
> > +
> > + shortnamebuf = pathname;
> > + for (i = 0; i < pathsize; i++) {
> > + if (pathname[i] == '\0')
> > + break;
> > + if (pathname[i] == '/')
> > + shortnamebuf = pathname + (i + 1);
> > + }
> > + strncpy(we_obj_info.shortname, shortnamebuf, SHORTNAMELENGTH);
> > + we_obj_info.path = pathname;
> > + inode = file_inode(file);
> > + we_obj_info.ino = inode->i_ino;
> > + we_obj_info.dmajor = MAJOR(inode->i_sb->s_dev);
> > + we_obj_info.dminor = MINOR(inode->i_sb->s_dev);
> > + we_obj_info.pid = current->pid;
> > + we_obj_info.pathsize = strlen(pathname);
> > + we_obj_info.ppid = current->tgid;
> > +
> > + rc = send_receive_we_obj_info(&we_obj_info, &checkresult);
> > + if (rc < 0)
> > + goto failure;
> > +
> > + rc = checkresult;
> > +
> > + if (rc == -EACCES)
> > + pr_warn("block %s, ino=%ld, devno=0x%x.\n",
> > + pathname, we_obj_info.ino,
> > + MKDEV(we_obj_info.dmajor, we_obj_info.dminor));
> > + else
> > + pr_info("permit %s, ino=%ld, devno=0x%x.\n",
> > + pathname, we_obj_info.ino,
> > + MKDEV(we_obj_info.dmajor, we_obj_info.dminor));
> > +
> > +failure:
> > + if (pathnamebuf != NULL) {
> > + kfree(pathnamebuf);
> > + pathnamebuf = NULL;
> > + }
> > +
> > + if ((rc != 0) && (rc != -EACCES))
> > + pr_warn("Checking white list does not work.\n");
> > +
> > + return rc;
> > +}
> > +
> > +/**
> > + * send_receive_we_obj_info - Send message and wait.
> > + *
> > + * @we_obj_info: Pointer to struct we_obj_info.
> > + * @result: Pointer to result of matching to white list.
> > + *
> > + * Returns 0 if succeeded, < 0 otherwise.
> > + */
> > +static int send_receive_we_obj_info(
> > + struct we_obj_info *we_obj_info, int *checkresult)
> > +{
> > + int i;
> > + int rc;
> > + struct we_req_q req;
> > +
> > + we_req_q_init(&req, we_obj_info);
> > +
> > + if ((we_req_q_search(&(req.data))) == NULL) {
> > + rc = we_req_q_push(&req);
> > + if (rc < 0) {
> > + pr_err("error %d at %d in %s\n", rc,
> > + __LINE__, __FILE__);
> > + goto failure;
> > + }
> > + }
> > +
> > + for (i = 0; i < MAXCOMRETRY; i++) {
> > + rc = send_we_obj_info(&req);
> > +
> > + if (likely(req.finish_flag == START_EXEC)) {
> > + break;
> > + } else if (unlikely(rc == -ERESTARTSYS)) {
> > + pr_info("Signal detected (%d)\n", rc);
> > + break;
> > + }
> > + }
> > +
> > + we_req_q_pop(&req);
> > +
> > + if (unlikely(i >= MAXCOMRETRY) && req.finish_flag != START_EXEC)
> {
> > + rc = -EINVAL;
> > + pr_err("error %d at %d in %s\n", rc, __LINE__, __FILE__);
> > + }
> > +
> > + *checkresult = req.permit;
> > +
> > +failure:
> > + return rc;
> > +}
> > +
> > +/**
> > + * we_security_bprm_check_main - Target for security_bprm_check.
> > + *
> > + * @bprm: Pointer to struct linux_binprm.
> > + *
> > + * Returns 0 if succeeded, < 0 otherwise.
> > + */
> > +int we_security_bprm_check_main(struct linux_binprm *bprm)
> > +{
> > + if (unlikely(!from_task))
> > + return 0;
> > +
> > + return we_check_main(bprm->file);
> > +}
> > +
> > +/**
> > + * we_security_mmap_check_main - Target for mmap_file.
> > + *
> > + * @file: Pointer to struct file to map.
> > + * @reqprot: Protection requested by the application.
> > + * @flags: Operational flags.
> > + *
> > + * Returns 0 if succeeded, < 0 otherwise.
> > + */
> > +int we_security_mmap_check_main(struct file *file,
> > + unsigned long reqprot, unsigned long flags)
> > +{
> > + if (unlikely(!from_task))
> > + return 0;
> > +
> > + if (!(reqprot & PROT_EXEC))
> > + return 0;
> > +
> > + if ((flags & MAP_EXECUTABLE))
> > + return 0;
> > +
> > + if (!file)
> > + return 0;
> > +
> > + if (!file->f_path.dentry)
> > + return 0;
> > +
> > + return we_check_main(file);
> > +}
> > diff --git a/security/whiteegret/request.c
> b/security/whiteegret/request.c
> > new file mode 100644
> > index 000000000000..7d28e133ebd6
> > --- /dev/null
> > +++ b/security/whiteegret/request.c
> > @@ -0,0 +1,151 @@
> > +/*
> > + * WhiteEgret Linux Security Module
> > + *
> > + * Copyright (C) 2017-2018 Toshiba Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation, version 2.
> > + */
> > +
> > +#include <linux/list.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/rwlock_types.h>
> > +#include <linux/slab.h>
> > +#include <linux/string.h>
> > +#include "request.h"
> > +
> > +struct we_req_q_head we_q_head;
> > +
> > +static int match_we_req_data(struct we_req_data *data1,
> > + struct we_req_data *data2);
> > +
> > +/**
> > + * we_req_q_init - Initialize the global variable we_q_head.
> > + *
> > + * Returns 0.
> > + */
> > +int we_req_q_head_init(void)
> > +{
> > + rwlock_init(&(we_q_head.lock));
> > + INIT_LIST_HEAD(&(we_q_head.head));
> > + init_waitqueue_head(&(we_q_head.waitq));
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * we_req_q_push - Add queue to tail of the list.
> > + *
> > + * @queue: Pointer to we_req_q to be added to the list.
> > + *
> > + * Returns 0.
> > + */
> > +int we_req_q_push(struct we_req_q *queue)
> > +{
> > + write_lock(&(we_q_head.lock));
> > + list_add_tail(&(queue->queue), &we_q_head.head);
> > + write_unlock(&(we_q_head.lock));
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * we_req_q_search - Search data in the list.
> > + *
> > + * @data: Pointer to we_req_data to be searched in the list.
> > + *
> > + * Returns pointer to data if data is found in the list,
> > + * NULL otherwise.
> > + */
> > +struct we_req_q *we_req_q_search(struct we_req_data *data)
> > +{
> > + struct list_head *p;
> > + struct we_req_q *req;
> > +
> > + read_lock(&(we_q_head.lock));
> > +
> > + list_for_each(p, &(we_q_head.head)) {
> > + req = list_entry(p, struct we_req_q, queue);
> > +
> > + if (match_we_req_data(data, &(req->data))) {
> > + read_unlock(&(we_q_head.lock));
> > + return req;
> > + }
> > + }
> > +
> > + read_unlock(&(we_q_head.lock));
> > +
> > + return NULL;
> > +}
> > +
> > +/**
> > + * we_req_q_init - Initialize queue.
> > + *
> > + * @req: Pointer to we_req_q to be initialized.
> > + * @info: Pointer to we_obj_info.
> > + *
> > + * Returns 0.
> > + */
> > +int we_req_q_init(struct we_req_q *req, struct we_obj_info *info)
> > +{
> > + req->finish_flag = STOP_EXEC;
> > + req->data.we_obj_info = info;
> > + req->permit = -EACCES;
> > + init_waitqueue_head(&req->waitq);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * we_req_q_pop - Delete queue in the list.
> > + *
> > + * Returns 0.
> > + */
> > +int we_req_q_pop(struct we_req_q *queue)
> > +{
> > + write_lock(&(we_q_head.lock));
> > + list_del(&queue->queue);
> > + write_unlock(&(we_q_head.lock));
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * match_we_req_data - Compare two we_req_data data.
> > + *
> > + * @data1: Pointer to we_req_data
> > + * @data2: Pointer to we_req_data
> > + *
> > + * Returns 1 if ppid of both we_req_data data are equal,
> > + * 0 otherwise.
> > + */
> > +static int match_we_req_data(struct we_req_data *data1,
> > + struct we_req_data *data2)
> > +{
> > + if (data1->we_obj_info->ppid == data2->we_obj_info->ppid)
> > + return 1;
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * we_req_q_cleanup - Cleaning up queues.
> > + *
> > + * Returns 0.
> > + */
> > +int we_req_q_cleanup(void)
> > +{
> > + struct list_head *p;
> > + struct we_req_q *req;
> > +
> > + write_lock(&(we_q_head.lock));
> > + list_for_each(p, &we_q_head.head) {
> > + req = list_entry(p, struct we_req_q, queue);
> > + req->finish_flag = START_EXEC;
> > + req->permit = -EINVAL;
> > + }
> > + write_unlock(&(we_q_head.lock));
> > +
> > + return 0;
> > +}
> > diff --git a/security/whiteegret/request.h
> b/security/whiteegret/request.h
> > new file mode 100644
> > index 000000000000..4a735fc70c63
> > --- /dev/null
> > +++ b/security/whiteegret/request.h
> > @@ -0,0 +1,52 @@
> > +/*
> > + * WhiteEgret Linux Security Module
> > + *
> > + * Copyright (C) 2017-2018 Toshiba Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation, version 2.
> > + */
> > +
> > +#ifndef _REQUEST_H
> > +#define _REQUEST_H
> > +
> > +#include <linux/sched.h>
> > +#include <linux/wait.h>
> > +
> > +#include "we.h"
> > +
> > +struct we_req_q_head {
> > + struct list_head head;
> > + rwlock_t lock;
> > + wait_queue_head_t waitq;
> > +};
> > +
> > +
> > +#define STOP_EXEC 0
> > +#define START_EXEC 1
> > +
> > +extern struct we_req_q_head we_q_head;
> > +
> > +/* Structure for information of request from kernel space to user space
> */
> > +struct we_req_data {
> > + struct we_obj_info *we_obj_info;
> > +};
> > +
> > +struct we_req_q {
> > + struct list_head queue;
> > + int finish_flag;
> > + struct we_req_data data;
> > + int permit;
> > + wait_queue_head_t waitq;
> > +};
> > +
> > +int we_req_q_pop(struct we_req_q *queue);
> > +int we_req_q_cleanup(void);
> > +
> > +int we_req_q_head_init(void);
> > +int we_req_q_init(struct we_req_q *req, struct we_obj_info *info);
> > +int we_req_q_push(struct we_req_q *queue);
> > +struct we_req_q *we_req_q_search(struct we_req_data *data);
> > +
> > +#endif /* _REQUEST_H */
> > diff --git a/security/whiteegret/we.h b/security/whiteegret/we.h
> > new file mode 100644
> > index 000000000000..fc14e67d4f7d
> > --- /dev/null
> > +++ b/security/whiteegret/we.h
> > @@ -0,0 +1,66 @@
> > +/*
> > + * WhiteEgret Linux Security Module
> > + *
> > + * Copyright (C) 2017-2018 Toshiba Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation, version 2.
> > + */
> > +
> > +#ifndef _WE_H
> > +#define _WE_H
> > +
> > +#include <linux/binfmts.h>
> > +
> > +/*
> > + * Initial size in byte of memory allocation to store the path
> > + * of an object file
> > + */
> > +#define EXPECTPATHSIZE 1023
> > +
> > +/*
> > + * Default size in byte to expand block that stores the path
> > + * of an object file when the memory block is too small
> > + * to store the path
> > + */
> > +#define ADDEDEXPECTPATHSIZE 1023
> > +
> > +/* Maximum length in byte of path of object file */
> > +#define MAXPATHSIZE 8184
> > +
> > +/* Maximum length in byte of name of executable file */
> > +#define SHORTNAMELENGTH 256
> > +
> > +/*
> > + * Maximum number of retry for sending the same message
> > + * to user whitelisting application
> > + */
> > +#define MAXCOMRETRY 10
> > +
> > +/* Timeout value in millisecond to aquire the semaphore */
> > +#define WERESULTTIMEOUT 1000
> > +
> > +/*
> > + * Structure for an object to be tested whether it is contained
> > + * in the whitelist or not
> > + */
> > +struct we_obj_info {
> > + unsigned long ino; /* inode number */
> > + unsigned int dmajor; /* major version of device
> number */
> > + unsigned int dminor; /* minor version of device
> number */
> > + char shortname[SHORTNAMELENGTH]; /* short name for the object */
> > + int pathsize;
> > + char *path; /* full path to the object */
> > + pid_t pid;
> > + pid_t ppid;
> > +};
> > +
> > +int we_security_bprm_check_main(struct linux_binprm *bprm);
> > +int we_security_mmap_check_main(struct file *file,
> > + unsigned long reqprot, unsigned long flags);
> > +
> > +int we_specific_init(void);
> > +int we_specific_exit(void);
> > +
> > +#endif /* _WE_H */
> > diff --git a/security/whiteegret/we_fs.c b/security/whiteegret/we_fs.c
> > new file mode 100644
> > index 000000000000..27b76f093814
> > --- /dev/null
> > +++ b/security/whiteegret/we_fs.c
> > @@ -0,0 +1,280 @@
> > +/*
> > + * WhiteEgret Linux Security Module
> > + *
> > + * Copyright (C) 2017-2018 Toshiba Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation, version 2.
> > + */
> > +
> > +#define pr_fmt(fmt) "WhiteEgret: " fmt
> > +
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/security.h>
> > +#include <linux/init.h>
> > +#include <linux/fs.h>
> > +#include <linux/wait.h>
> > +#include <linux/sched.h>
> > +#include <linux/uaccess.h>
> > +#include <linux/cdev.h>
> > +
> > +#include "we_fs.h"
> > +
> > +#define static_assert(constexpr) \
> > + char dummy[(constexpr) ? 1 : -1] __attribute__((unused))
> > +
> > +#define WE_COPY_TO_USER(to, from, ret) \
> > + do { \
> > + static_assert(sizeof((to)) == sizeof((from))); \
> > + (ret) = copy_to_user(&(to), &(from), sizeof(to)); \
> > + } while (0)
> > +
> > +#define WE_COPY_FROM_USER(to, from, ret) \
> > + do { \
> > + static_assert(sizeof((to)) == sizeof((from))); \
> > + (ret) = copy_from_user(&(to), &(from), sizeof(to)); \
> > + } while (0)
> > +
> > +static struct we_req_q_head *root;
> > +struct task_struct *from_task;
> > +static DEFINE_RWLOCK(from_task_lock);
> > +
> > +static int check_we_pathsize(struct we_req_q *we_req, int size)
> > +{
> > + if (size - sizeof(*we_req)
> > + > we_req->data.we_obj_info->pathsize)
> > + return 0;
> > + else
> > + return -1;
> > +}
> > +
> > +static int set_we_req_info(struct we_req_user *user,
> > + struct we_obj_info *info)
> > +{
> > + unsigned long ret;
> > +
> > + WE_COPY_TO_USER(user->ino, info->ino, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > + WE_COPY_TO_USER(user->dmajor, info->dmajor, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > + WE_COPY_TO_USER(user->dminor, info->dminor, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > + WE_COPY_TO_USER(user->pid, info->pid, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > + WE_COPY_TO_USER(user->ppid, info->ppid, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > + WE_COPY_TO_USER(user->shortname, info->shortname, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > + WE_COPY_TO_USER(user->pathsize, info->pathsize, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > + ret = copy_to_user(user->path, info->path, info->pathsize + 1);
> > + if (ret != 0)
> > + return -EFAULT;
> > +
> > + return 0;
> > +}
> > +
> > +static int set_we_ack(struct we_ack *to, struct we_ack *from)
> > +{
> > + unsigned long ret;
> > +
> > + WE_COPY_FROM_USER(to->pid, from->pid, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > + WE_COPY_FROM_USER(to->permit, from->permit, ret);
> > + if (ret != 0)
> > + return -EFAULT;
> > +
> > + return 0;
> > +}
> > +
> > +static struct we_req_user *get_alive_we_req(struct we_req_q_head
> *root,
> > + void *buf, int size)
> > +{
> > + int pathsize;
> > + struct list_head *p;
> > + struct we_req_q *req;
> > + struct we_req_user *user = NULL;
> > +
> > + write_lock(&root->lock);
> > + list_for_each(p, &root->head) {
> > + req = list_entry(p, struct we_req_q, queue);
> > + if (req->finish_flag == STOP_EXEC) {
> > + if (unlikely(check_we_pathsize(req, size)))
> > + goto SIZE_ERROR;
> > + user = (struct we_req_user *)buf;
> > + set_we_req_info(user, req->data.we_obj_info);
> > + break;
> > + }
> > + }
> > + write_unlock(&root->lock);
> > +
> > + return user;
> > +SIZE_ERROR:
> > + pathsize = req->data.we_obj_info->pathsize;
> > + req->permit = -EACCES;
> > + req->finish_flag = START_EXEC;
> > + write_unlock(&root->lock);
> > + pr_err("Path length of exec is too long (%d).\n", pathsize);
> > + return NULL;
> > +}
> > +
> > +static ssize_t send_ack(struct we_req_q_head *root, struct we_ack *ack)
> > +{
> > + struct list_head *p;
> > + struct we_req_q *req = NULL, *temp;
> > +
> > + write_lock(&root->lock);
> > + list_for_each(p, &root->head) {
> > + temp = list_entry(p, struct we_req_q, queue);
> > + if (temp->data.we_obj_info->pid == ack->pid) {
> > + req = temp;
> > + req->permit = ack->permit;
> > + wake_up_interruptible_sync(&req->waitq);
> > + req->finish_flag = START_EXEC;
> > + }
> > + }
> > + write_unlock(&root->lock);
> > +
> > + if (unlikely(!req)) {
> > + pr_warn("%s: can not find we_req. pid(%d)\n",
> > + __func__, ack->pid);
> > + return -EACCES;
> > + }
> > + return sizeof(*ack);
> > +}
> > +
> > +static ssize_t we_driver_read(struct file *file, char *buf,
> > + size_t size, loff_t *off)
> > +{
> > + int ret;
> > + struct we_req_user *user;
> > +
> > + while (1) {
> > + ret = wait_event_interruptible(root->waitq,
> > + (user = get_alive_we_req(root, buf,
> size)));
> > + if (unlikely(ret < 0)) {
> > + pr_info("%s: signal (%d)", __func__, ret);
> > + return 0;
> > + }
> > + if (likely(user))
> > + break;
> > + }
> > +
> > + return sizeof(*user) + user->pathsize + 1;
> > +}
> > +
> > +static ssize_t we_driver_write(struct file *file, const char *buf,
> > + size_t size, loff_t *off)
> > +{
> > + int rc;
> > + ssize_t ret;
> > + struct we_ack ack;
> > +
> > + rc = set_we_ack(&ack, (struct we_ack *)((void *)buf));
> > + if (rc < 0)
> > + return (ssize_t)rc;
> > + ret = send_ack(root, &ack);
> > +
> > + return ret;
> > +}
> > +
> > +static long we_driver_ioctl(struct file *file,
> > + unsigned int arg0, unsigned long arg1)
> > +{
> > + return 0;
> > +}
> > +
> > +static int we_driver_release(struct inode *inode, struct file *filp)
> > +{
> > + int ret = 0;
> > +
> > + write_lock(&from_task_lock);
> > + if (!from_task) {
> > + pr_warn("WhiteEgret has not started.\n");
> > + ret = -EACCES;
> > + goto END;
> > + }
> > + if (from_task != current) {
> > + pr_warn("This task is not registered to WhiteEgret.\n");
> > + ret = -EACCES;
> > + goto END;
> > + }
> > + from_task = NULL;
> > + we_req_q_cleanup();
> > +END:
> > + write_unlock(&from_task_lock);
> > + return ret;
> > +}
> > +
> > +static int we_driver_open(struct inode *inode, struct file *filp)
> > +{
> > + write_lock(&from_task_lock);
> > + if (from_task) {
> > + write_unlock(&(from_task_lock));
> > + pr_warn("WhiteEgret has already started.\n");
> > + return -EACCES;
> > + }
> > +
> > + from_task = current;
> > + root = &we_q_head;
> > + write_unlock(&from_task_lock);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct file_operations we_driver_fops = {
> > + .owner = THIS_MODULE,
> > + .read = we_driver_read,
> > + .write = we_driver_write,
> > + .unlocked_ioctl = we_driver_ioctl,
> > + .open = we_driver_open,
> > + .release = we_driver_release,
> > +};
> > +
> > +int we_fs_init(void)
> > +{
> > + struct dentry *we_dir;
> > + struct dentry *wecom;
> > +
> > + we_dir = securityfs_create_dir(WE_FS_DIR_NAME, NULL);
> > + if (IS_ERR(we_dir))
> > + return PTR_ERR(we_dir);
> > +
> > + wecom = securityfs_create_file(WE_DEV_NAME, 0600, we_dir, NULL,
> &we_driver_fops);
> > + if (IS_ERR(wecom)) {
> > + securityfs_remove(we_dir);
> > + return PTR_ERR(wecom);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * send_we_obj_info - Wait response from user's whitelisting application.
> > + *
> > + * @req: Pointer to struct we_req_q.
> > + *
> > + * Returns 0 if succeeded, < 0 otherwise.
> > + */
> > +int send_we_obj_info(struct we_req_q *req)
> > +{
> > + /* If there exists queue waiting for this request req done,
> > + * then wake it up.
> > + */
> > + if (waitqueue_active(&(we_q_head.waitq)))
> > + wake_up(&(we_q_head.waitq));
> > +
> > + return wait_event_interruptible_timeout(req->waitq,
> > + (req->finish_flag == START_EXEC),
> > + WERESULTTIMEOUT);
> > +}
> > diff --git a/security/whiteegret/we_fs.h b/security/whiteegret/we_fs.h
> > new file mode 100644
> > index 000000000000..9af245d7aca4
> > --- /dev/null
> > +++ b/security/whiteegret/we_fs.h
> > @@ -0,0 +1,23 @@
> > +/*
> > + * WhiteEgret Linux Security Module
> > + *
> > + * Copyright (C) 2017-2018 Toshiba Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation, version 2.
> > + */
> > +
> > +#ifndef _WE_FS_H
> > +#define _WE_FS_H
> > +
> > +#include "request.h"
> > +#include "we_fs_common.h"
> > +
> > +extern struct task_struct *from_task;
> > +
> > +int we_fs_init(void);
> > +
> > +int send_we_obj_info(struct we_req_q *req);
> > +
> > +#endif /* _WE_FS_H */
> > diff --git a/security/whiteegret/we_fs_common.h
> b/security/whiteegret/we_fs_common.h
> > new file mode 100644
> > index 000000000000..259f300d9738
> > --- /dev/null
> > +++ b/security/whiteegret/we_fs_common.h
> > @@ -0,0 +1,36 @@
> > +/*
> > + * WhiteEgret Linux Security Module
> > + *
> > + * Copyright (C) 2017-2018 Toshiba Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * as published by the Free Software Foundation, version 2.
> > + */
> > +
> > +#ifndef _WE_FS_COMMON_H
> > +#define _WE_FS_COMMON_H
> > +
> > +#define WE_FS_DIR_NAME "whiteegret"
> > +#define WE_DEV_NAME "wecom"
> > +#define WE_DEV_PATH
> "/sys/kernel/security/"WE_FS_DIR_NAME"/"WE_DEV_NAME
> > +
> > +#define SHORTNAMELENGTH 256
> > +
> > +struct we_req_user {
> > + unsigned long ino;
> > + unsigned int dmajor;
> > + unsigned int dminor;
> > + pid_t pid;
> > + pid_t ppid;
> > + char shortname[SHORTNAMELENGTH];
> > + int pathsize;
> > + char path[0];
> > +};
> > +
> > +struct we_ack {
> > + int permit;
> > + pid_t pid;
> > +};
> > +
> > +#endif /* _WE_FS_COMMON_H */
>
> --
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