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
+
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 */
--
2.14.1
