Commit ddbf9ef3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge master.kernel.org:/pub/scm/linux/kernel/git/chrisw/lsm-2.6

parents 5d54e69c 2c40579b
......@@ -1907,6 +1907,11 @@ extern int register_security (struct security_operations *ops);
extern int unregister_security (struct security_operations *ops);
extern int mod_reg_security (const char *name, struct security_operations *ops);
extern int mod_unreg_security (const char *name, struct security_operations *ops);
extern struct dentry *securityfs_create_file(const char *name, mode_t mode,
struct dentry *parent, void *data,
struct file_operations *fops);
extern struct dentry *securityfs_create_dir(const char *name, struct dentry *parent);
extern void securityfs_remove(struct dentry *dentry);
#else /* CONFIG_SECURITY */
......
......@@ -35,6 +35,7 @@ config KEYS_DEBUG_PROC_KEYS
config SECURITY
bool "Enable different security models"
depends on SYSFS
help
This allows you to choose different security modules to be
configured into your kernel.
......
......@@ -11,7 +11,7 @@ obj-y += commoncap.o
endif
# Object file lists
obj-$(CONFIG_SECURITY) += security.o dummy.o
obj-$(CONFIG_SECURITY) += security.o dummy.o inode.o
# Must precede capability.o in order to stack properly.
obj-$(CONFIG_SECURITY_SELINUX) += selinux/built-in.o
obj-$(CONFIG_SECURITY_CAPABILITIES) += commoncap.o capability.o
......
/*
* inode.c - securityfs
*
* Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* Based on fs/debugfs/inode.c which had the following copyright notice:
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 IBM Inc.
*/
/* #define DEBUG */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/namei.h>
#include <linux/security.h>
#define SECURITYFS_MAGIC 0x73636673
static struct vfsmount *mount;
static int mount_count;
/*
* TODO:
* I think I can get rid of these default_file_ops, but not quite sure...
*/
static ssize_t default_read_file(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
return 0;
}
static ssize_t default_write_file(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return count;
}
static int default_open(struct inode *inode, struct file *file)
{
if (inode->u.generic_ip)
file->private_data = inode->u.generic_ip;
return 0;
}
static struct file_operations default_file_ops = {
.read = default_read_file,
.write = default_write_file,
.open = default_open,
};
static struct inode *get_inode(struct super_block *sb, int mode, dev_t dev)
{
struct inode *inode = new_inode(sb);
if (inode) {
inode->i_mode = mode;
inode->i_uid = 0;
inode->i_gid = 0;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
switch (mode & S_IFMT) {
default:
init_special_inode(inode, mode, dev);
break;
case S_IFREG:
inode->i_fop = &default_file_ops;
break;
case S_IFDIR:
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inode->i_nlink++;
break;
}
}
return inode;
}
/* SMP-safe */
static int mknod(struct inode *dir, struct dentry *dentry,
int mode, dev_t dev)
{
struct inode *inode;
int error = -EPERM;
if (dentry->d_inode)
return -EEXIST;
inode = get_inode(dir->i_sb, mode, dev);
if (inode) {
d_instantiate(dentry, inode);
dget(dentry);
error = 0;
}
return error;
}
static int mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
int res;
mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
res = mknod(dir, dentry, mode, 0);
if (!res)
dir->i_nlink++;
return res;
}
static int create(struct inode *dir, struct dentry *dentry, int mode)
{
mode = (mode & S_IALLUGO) | S_IFREG;
return mknod(dir, dentry, mode, 0);
}
static inline int positive(struct dentry *dentry)
{
return dentry->d_inode && !d_unhashed(dentry);
}
static int fill_super(struct super_block *sb, void *data, int silent)
{
static struct tree_descr files[] = {{""}};
return simple_fill_super(sb, SECURITYFS_MAGIC, files);
}
static struct super_block *get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *data)
{
return get_sb_single(fs_type, flags, data, fill_super);
}
static struct file_system_type fs_type = {
.owner = THIS_MODULE,
.name = "securityfs",
.get_sb = get_sb,
.kill_sb = kill_litter_super,
};
static int create_by_name(const char *name, mode_t mode,
struct dentry *parent,
struct dentry **dentry)
{
int error = 0;
*dentry = NULL;
/* If the parent is not specified, we create it in the root.
* We need the root dentry to do this, which is in the super
* block. A pointer to that is in the struct vfsmount that we
* have around.
*/
if (!parent ) {
if (mount && mount->mnt_sb) {
parent = mount->mnt_sb->s_root;
}
}
if (!parent) {
pr_debug("securityfs: Ah! can not find a parent!\n");
return -EFAULT;
}
down(&parent->d_inode->i_sem);
*dentry = lookup_one_len(name, parent, strlen(name));
if (!IS_ERR(dentry)) {
if ((mode & S_IFMT) == S_IFDIR)
error = mkdir(parent->d_inode, *dentry, mode);
else
error = create(parent->d_inode, *dentry, mode);
} else
error = PTR_ERR(dentry);
up(&parent->d_inode->i_sem);
return error;
}
/**
* securityfs_create_file - create a file in the securityfs filesystem
*
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this paramater is NULL, then the
* file will be created in the root of the securityfs filesystem.
* @data: a pointer to something that the caller will want to get to later
* on. The inode.u.generic_ip pointer will point to this value on
* the open() call.
* @fops: a pointer to a struct file_operations that should be used for
* this file.
*
* This is the basic "create a file" function for securityfs. It allows for a
* wide range of flexibility in createing a file, or a directory (if you
* want to create a directory, the securityfs_create_dir() function is
* recommended to be used instead.)
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the securityfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, NULL will be returned.
*
* If securityfs is not enabled in the kernel, the value -ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* NULL or !NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *securityfs_create_file(const char *name, mode_t mode,
struct dentry *parent, void *data,
struct file_operations *fops)
{
struct dentry *dentry = NULL;
int error;
pr_debug("securityfs: creating file '%s'\n",name);
error = simple_pin_fs("securityfs", &mount, &mount_count);
if (error) {
dentry = ERR_PTR(error);
goto exit;
}
error = create_by_name(name, mode, parent, &dentry);
if (error) {
dentry = ERR_PTR(error);
simple_release_fs(&mount, &mount_count);
goto exit;
}
if (dentry->d_inode) {
if (fops)
dentry->d_inode->i_fop = fops;
if (data)
dentry->d_inode->u.generic_ip = data;
}
exit:
return dentry;
}
EXPORT_SYMBOL_GPL(securityfs_create_file);
/**
* securityfs_create_dir - create a directory in the securityfs filesystem
*
* @name: a pointer to a string containing the name of the directory to
* create.
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this paramater is NULL, then the
* directory will be created in the root of the securityfs filesystem.
*
* This function creates a directory in securityfs with the given name.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the securityfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, NULL will be returned.
*
* If securityfs is not enabled in the kernel, the value -ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* NULL or !NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
{
return securityfs_create_file(name,
S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
parent, NULL, NULL);
}
EXPORT_SYMBOL_GPL(securityfs_create_dir);
/**
* securityfs_remove - removes a file or directory from the securityfs filesystem
*
* @dentry: a pointer to a the dentry of the file or directory to be
* removed.
*
* This function removes a file or directory in securityfs that was previously
* created with a call to another securityfs function (like
* securityfs_create_file() or variants thereof.)
*
* This function is required to be called in order for the file to be
* removed, no automatic cleanup of files will happen when a module is
* removed, you are responsible here.
*/
void securityfs_remove(struct dentry *dentry)
{
struct dentry *parent;
if (!dentry)
return;
parent = dentry->d_parent;
if (!parent || !parent->d_inode)
return;
down(&parent->d_inode->i_sem);
if (positive(dentry)) {
if (dentry->d_inode) {
if (S_ISDIR(dentry->d_inode->i_mode))
simple_rmdir(parent->d_inode, dentry);
else
simple_unlink(parent->d_inode, dentry);
dput(dentry);
}
}
up(&parent->d_inode->i_sem);
simple_release_fs(&mount, &mount_count);
}
EXPORT_SYMBOL_GPL(securityfs_remove);
static decl_subsys(security, NULL, NULL);
static int __init securityfs_init(void)
{
int retval;
kset_set_kset_s(&security_subsys, kernel_subsys);
retval = subsystem_register(&security_subsys);
if (retval)
return retval;
retval = register_filesystem(&fs_type);
if (retval)
subsystem_unregister(&security_subsys);
return retval;
}
static void __exit securityfs_exit(void)
{
simple_release_fs(&mount, &mount_count);
unregister_filesystem(&fs_type);
subsystem_unregister(&security_subsys);
}
core_initcall(securityfs_init);
module_exit(securityfs_exit);
MODULE_LICENSE("GPL");
......@@ -118,69 +118,6 @@ MODULE_PARM_DESC(hideHash, "When set to 0, reading seclvl/passwd from sysfs "
} \
} while (0)
/**
* kobject stuff
*/
struct subsystem seclvl_subsys;
struct seclvl_obj {
char *name;
struct list_head slot_list;
struct kobject kobj;
};
/**
* There is a seclvl_attribute struct for each file in sysfs.
*
* In our case, we have one of these structs for "passwd" and another
* for "seclvl".
*/
struct seclvl_attribute {
struct attribute attr;
ssize_t(*show) (struct seclvl_obj *, char *);
ssize_t(*store) (struct seclvl_obj *, const char *, size_t);
};
/**
* When this function is called, one of the files in sysfs is being
* written to. attribute->store is a function pointer to whatever the
* struct seclvl_attribute store function pointer points to. It is
* unique for "passwd" and "seclvl".
*/
static ssize_t
seclvl_attr_store(struct kobject *kobj,
struct attribute *attr, const char *buf, size_t len)
{
struct seclvl_obj *obj = container_of(kobj, struct seclvl_obj, kobj);
struct seclvl_attribute *attribute =
container_of(attr, struct seclvl_attribute, attr);
return attribute->store ? attribute->store(obj, buf, len) : -EIO;
}
static ssize_t
seclvl_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
{
struct seclvl_obj *obj = container_of(kobj, struct seclvl_obj, kobj);
struct seclvl_attribute *attribute =
container_of(attr, struct seclvl_attribute, attr);
return attribute->show ? attribute->show(obj, buf) : -EIO;
}
/**
* Callback function pointers for show and store
*/
static struct sysfs_ops seclvlfs_sysfs_ops = {
.show = seclvl_attr_show,
.store = seclvl_attr_store,
};
static struct kobj_type seclvl_ktype = {
.sysfs_ops = &seclvlfs_sysfs_ops
};
decl_subsys(seclvl, &seclvl_ktype, NULL);
/**
* The actual security level. Ranges between -1 and 2 inclusive.
*/
......@@ -212,97 +149,44 @@ static int seclvl_sanity(int reqlvl)
return 0;
}
/**
* Called whenever the user reads the sysfs handle to this kernel
* object
*/
static ssize_t seclvl_read_file(struct seclvl_obj *obj, char *buff)
{
return snprintf(buff, PAGE_SIZE, "%d\n", seclvl);
}
/**
* security level advancement rules:
* Valid levels are -1 through 2, inclusive.
* From -1, stuck. [ in case compiled into kernel ]
* From 0 or above, can only increment.
*/
static int do_seclvl_advance(int newlvl)
static void do_seclvl_advance(void *data, u64 val)
{
if (newlvl <= seclvl) {
seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl "
"[%d]\n", newlvl);
return -EINVAL;
}
int ret;
int newlvl = (int)val;
ret = seclvl_sanity(newlvl);
if (ret)
return;
if (newlvl > 2) {
seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl "
"[%d]\n", newlvl);
return -EINVAL;
return;
}
if (seclvl == -1) {
seclvl_printk(1, KERN_WARNING, "Not allowed to advance to "
"seclvl [%d]\n", seclvl);
return -EPERM;
return;
}
seclvl = newlvl;
return 0;
seclvl = newlvl; /* would it be more "correct" to set *data? */
return;
}
/**
* Called whenever the user writes to the sysfs handle to this kernel
* object (seclvl/seclvl). It expects a single-digit number.
*/
static ssize_t
seclvl_write_file(struct seclvl_obj *obj, const char *buff, size_t count)
static u64 seclvl_int_get(void *data)
{
unsigned long val;
if (count > 2 || (count == 2 && buff[1] != '\n')) {
seclvl_printk(1, KERN_WARNING, "Invalid value passed to "
"seclvl: [%s]\n", buff);
return -EINVAL;
}
val = buff[0] - 48;
if (seclvl_sanity(val)) {
seclvl_printk(1, KERN_WARNING, "Illegal secure level "
"requested: [%d]\n", (int)val);
return -EPERM;
}
if (do_seclvl_advance(val)) {
seclvl_printk(0, KERN_ERR, "Failure advancing security level "
"to %lu\n", val);
}
return count;
return *(int *)data;
}
/* Generate sysfs_attr_seclvl */
static struct seclvl_attribute sysfs_attr_seclvl =
__ATTR(seclvl, (S_IFREG | S_IRUGO | S_IWUSR), seclvl_read_file,
seclvl_write_file);
DEFINE_SIMPLE_ATTRIBUTE(seclvl_file_ops, seclvl_int_get, do_seclvl_advance, "%lld\n");
static unsigned char hashedPassword[SHA1_DIGEST_SIZE];
/**
* Called whenever the user reads the sysfs passwd handle.
*/
static ssize_t seclvl_read_passwd(struct seclvl_obj *obj, char *buff)
{
/* So just how good *is* your password? :-) */
char tmp[3];
int i = 0;
buff[0] = '\0';
if (hideHash) {
/* Security through obscurity */
return 0;
}
while (i < SHA1_DIGEST_SIZE) {
snprintf(tmp, 3, "%02x", hashedPassword[i]);
strncat(buff, tmp, 2);
i++;
}
strcat(buff, "\n");
return ((SHA1_DIGEST_SIZE * 2) + 1);
}
/**
* Converts a block of plaintext of into its SHA1 hashed value.
*
......@@ -347,12 +231,15 @@ plaintext_to_sha1(unsigned char *hash, const char *plaintext, int len)
* object. It hashes the password and compares the hashed results.
*/
static ssize_t
seclvl_write_passwd(struct seclvl_obj *obj, const char *buff, size_t count)
passwd_write_file(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
int i;
unsigned char tmp[SHA1_DIGEST_SIZE];
char *page;
int rc;
int len;
if (!*passwd && !*sha1_passwd) {
seclvl_printk(0, KERN_ERR, "Attempt to password-unlock the "
"seclvl module, but neither a plain text "
......@@ -363,13 +250,26 @@ seclvl_write_passwd(struct seclvl_obj *obj, const char *buff, size_t count)
"maintainer about this event.\n");
return -EINVAL;
}
len = strlen(buff);
if (count < 0 || count >= PAGE_SIZE)
return -ENOMEM;
if (*ppos != 0) {
return -EINVAL;
}
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
len = -EFAULT;
if (copy_from_user(page, buf, count))
goto out;
len = strlen(page);
/* ``echo "secret" > seclvl/passwd'' includes a newline */
if (buff[len - 1] == '\n') {
if (page[len - 1] == '\n') {
len--;
}
/* Hash the password, then compare the hashed values */
if ((rc = plaintext_to_sha1(tmp, buff, len))) {
if ((rc = plaintext_to_sha1(tmp, page, len))) {
seclvl_printk(0, KERN_ERR, "Error hashing password: rc = "
"[%d]\n", rc);
return rc;
......@@ -382,13 +282,16 @@ seclvl_write_passwd(struct seclvl_obj *obj, const char *buff, size_t count)
seclvl_printk(0, KERN_INFO,
"Password accepted; seclvl reduced to 0.\n");
seclvl = 0;
return count;
len = count;
out:
free_page((unsigned long)page);
return len;
}
/* Generate sysfs_attr_passwd */
static struct seclvl_attribute sysfs_attr_passwd =
__ATTR(passwd, (S_IFREG | S_IRUGO | S_IWUSR), seclvl_read_passwd,
seclvl_write_passwd);
static struct file_operations passwd_file_ops = {
.write = passwd_write_file,
};
/**
* Explicitely disallow ptrace'ing the init process.
......@@ -647,22 +550,34 @@ static int processPassword(void)
}