On 2/28/2018 11:38 PM, Masanobu Koike wrote:
> This RFC provides implementation of WhiteEgret.
>
> Signed-off-by: Masanobu Koike <masanobu2.ko...@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?
> 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 */
