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authorLinus Torvalds <torvalds@g5.osdl.org>2005-09-13 09:48:54 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-13 09:48:54 -0700
commitddbf9ef385bfbef897210733abfb73cb9b94ecec (patch)
tree64a9e965a71eef13e813a3327f8d74aa7168ee19 /security
parent5d54e69c68c05b162a56f9914cae72afd7e6f40a (diff)
parent2c40579bdc2a94977fcff2521d5b53a97c33e77a (diff)
downloadlinux-linaro-stable-ddbf9ef385bfbef897210733abfb73cb9b94ecec.tar.gz
Merge master.kernel.org:/pub/scm/linux/kernel/git/chrisw/lsm-2.6
Diffstat (limited to 'security')
-rw-r--r--security/Kconfig1
-rw-r--r--security/Makefile2
-rw-r--r--security/inode.c347
-rw-r--r--security/seclvl.c228
4 files changed, 419 insertions, 159 deletions
diff --git a/security/Kconfig b/security/Kconfig
index dcf04a09185d..64d3f1e9ca85 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -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.
diff --git a/security/Makefile b/security/Makefile
index 197cc2f3f1ec..8cbbf2f36709 100644
--- a/security/Makefile
+++ b/security/Makefile
@@ -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
diff --git a/security/inode.c b/security/inode.c
new file mode 100644
index 000000000000..a5964502ae30
--- /dev/null
+++ b/security/inode.c
@@ -0,0 +1,347 @@
+/*
+ * 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");
+
diff --git a/security/seclvl.c b/security/seclvl.c
index 96b1f2122f67..dc4e17b6eaf6 100644
--- a/security/seclvl.c
+++ b/security/seclvl.c
@@ -119,69 +119,6 @@ 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.
*/
static int seclvl;
@@ -213,97 +150,44 @@ static int seclvl_sanity(int reqlvl)
}
/**
- * 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.
*
* It would be nice if crypto had a wrapper to do this for us linear
@@ -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)
}
/**
- * Sysfs registrations
+ * securityfs registrations
*/
-static int doSysfsRegistrations(void)
+struct dentry *dir_ino, *seclvl_ino, *passwd_ino;
+
+static int seclvlfs_register(void)
{
- int rc = 0;
- if ((rc = subsystem_register(&seclvl_subsys))) {
- seclvl_printk(0, KERN_WARNING,
- "Error [%d] registering seclvl subsystem\n", rc);
- return rc;
- }
- sysfs_create_file(&seclvl_subsys.kset.kobj, &sysfs_attr_seclvl.attr);
+ dir_ino = securityfs_create_dir("seclvl", NULL);
+ if (!dir_ino)
+ return -EFAULT;
+
+ seclvl_ino = securityfs_create_file("seclvl", S_IRUGO | S_IWUSR,
+ dir_ino, &seclvl, &seclvl_file_ops);
+ if (!seclvl_ino)
+ goto out_deldir;
if (*passwd || *sha1_passwd) {
- sysfs_create_file(&seclvl_subsys.kset.kobj,
- &sysfs_attr_passwd.attr);
+ passwd_ino = securityfs_create_file("passwd", S_IRUGO | S_IWUSR,
+ dir_ino, NULL, &passwd_file_ops);
+ if (!passwd_ino)
+ goto out_delf;
}
return 0;
+
+out_deldir:
+ securityfs_remove(dir_ino);
+out_delf:
+ securityfs_remove(seclvl_ino);
+
+ return -EFAULT;
}
/**
@@ -677,8 +592,6 @@ static int __init seclvl_init(void)
rc = -EINVAL;
goto exit;
}
- sysfs_attr_seclvl.attr.owner = THIS_MODULE;
- sysfs_attr_passwd.attr.owner = THIS_MODULE;
if (initlvl < -1 || initlvl > 2) {
seclvl_printk(0, KERN_ERR, "Error: bad initial securelevel "
"[%d].\n", initlvl);
@@ -706,7 +619,7 @@ static int __init seclvl_init(void)
} /* if primary module registered */
secondary = 1;
} /* if we registered ourselves with the security framework */
- if ((rc = doSysfsRegistrations())) {
+ if ((rc = seclvlfs_register())) {
seclvl_printk(0, KERN_ERR, "Error registering with sysfs\n");
goto exit;
}
@@ -724,12 +637,11 @@ static int __init seclvl_init(void)
*/
static void __exit seclvl_exit(void)
{
- sysfs_remove_file(&seclvl_subsys.kset.kobj, &sysfs_attr_seclvl.attr);
+ securityfs_remove(seclvl_ino);
if (*passwd || *sha1_passwd) {
- sysfs_remove_file(&seclvl_subsys.kset.kobj,
- &sysfs_attr_passwd.attr);
+ securityfs_remove(passwd_ino);
}
- subsystem_unregister(&seclvl_subsys);
+ securityfs_remove(dir_ino);
if (secondary == 1) {
mod_unreg_security(MY_NAME, &seclvl_ops);
} else if (unregister_security(&seclvl_ops)) {