* Copyright (c) 2001 WireX Communications, Inc <chris@wirex.com>
* Copyright (c) 2001 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (c) 2002 International Business Machines <robb@austin.ibm.com>
+ * Copyright (c) 2006 Davi E. M. Arnaut <davi.arnaut@gmail.com>
*
* 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
#include <linux/kobject.h>
#include <linux/crypto.h>
#include <asm/scatterlist.h>
+#include <linux/scatterlist.h>
#include <linux/gfp.h>
#include <linux/sysfs.h>
} \
} 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) : 0);
-}
-
-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) : 0);
-}
-
-/**
- * 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.
*/
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.
*
* people...
*/
static int
-plaintext_to_sha1(unsigned char *hash, const char *plaintext, int len)
+plaintext_to_sha1(unsigned char *hash, const char *plaintext, unsigned int len)
{
- char *pgVirtAddr;
struct crypto_tfm *tfm;
- struct scatterlist sg[1];
+ struct scatterlist sg;
if (len > PAGE_SIZE) {
seclvl_printk(0, KERN_ERR, "Plaintext password too large (%d "
"characters). Largest possible is %lu "
"bytes.\n", len, PAGE_SIZE);
- return -ENOMEM;
+ return -EINVAL;
}
- tfm = crypto_alloc_tfm("sha1", 0);
+ tfm = crypto_alloc_tfm("sha1", CRYPTO_TFM_REQ_MAY_SLEEP);
if (tfm == NULL) {
seclvl_printk(0, KERN_ERR,
"Failed to load transform for SHA1\n");
- return -ENOSYS;
+ return -EINVAL;
}
- // Just get a new page; don't play around with page boundaries
- // and scatterlists.
- pgVirtAddr = (char *)__get_free_page(GFP_KERNEL);
- sg[0].page = virt_to_page(pgVirtAddr);
- sg[0].offset = 0;
- sg[0].length = len;
- strncpy(pgVirtAddr, plaintext, len);
+ sg_init_one(&sg, (u8 *)plaintext, len);
crypto_digest_init(tfm);
- crypto_digest_update(tfm, sg, 1);
+ crypto_digest_update(tfm, &sg, 1);
crypto_digest_final(tfm, hash);
crypto_free_tfm(tfm);
- free_page((unsigned long)pgVirtAddr);
return 0;
}
* 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];
- int rc;
+ char *p;
int len;
+ unsigned char tmp[SHA1_DIGEST_SIZE];
+
if (!*passwd && !*sha1_passwd) {
seclvl_printk(0, KERN_ERR, "Attempt to password-unlock the "
"seclvl module, but neither a plain text "
"maintainer about this event.\n");
return -EINVAL;
}
- len = strlen(buff);
+
+ if (count >= PAGE_SIZE)
+ return -EINVAL;
+ if (*ppos != 0)
+ return -EINVAL;
+ p = kmalloc(count, GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ len = -EFAULT;
+ if (copy_from_user(p, buf, count))
+ goto out;
+
+ len = count;
/* ``echo "secret" > seclvl/passwd'' includes a newline */
- if (buff[len - 1] == '\n') {
+ if (p[len - 1] == '\n')
len--;
- }
/* Hash the password, then compare the hashed values */
- if ((rc = plaintext_to_sha1(tmp, buff, len))) {
+ if ((len = plaintext_to_sha1(tmp, p, len))) {
seclvl_printk(0, KERN_ERR, "Error hashing password: rc = "
- "[%d]\n", rc);
- return rc;
- }
- for (i = 0; i < SHA1_DIGEST_SIZE; i++) {
- if (hashedPassword[i] != tmp[i]) {
- return -EPERM;
- }
+ "[%d]\n", len);
+ goto out;
}
+
+ len = -EPERM;
+ if (memcmp(hashedPassword, tmp, SHA1_DIGEST_SIZE))
+ goto out;
+
seclvl_printk(0, KERN_INFO,
"Password accepted; seclvl reduced to 0.\n");
seclvl = 0;
- return count;
+ len = count;
+
+out:
+ kfree (p);
+ 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.
*/
static int seclvl_ptrace(struct task_struct *parent, struct task_struct *child)
{
- if (seclvl >= 0) {
- if (child->pid == 1) {
- seclvl_printk(1, KERN_WARNING, "Attempt to ptrace "
- "the init process dissallowed in "
- "secure level %d\n", seclvl);
- return -EPERM;
- }
+ if (seclvl >= 0 && child->pid == 1) {
+ seclvl_printk(1, KERN_WARNING, "Attempt to ptrace "
+ "the init process dissallowed in "
+ "secure level %d\n", seclvl);
+ return -EPERM;
}
return 0;
}
*/
static int seclvl_capable(struct task_struct *tsk, int cap)
{
+ int rc = 0;
+
/* init can do anything it wants */
if (tsk->pid == 1)
return 0;
- switch (seclvl) {
- case 2:
- /* fall through */
- case 1:
- if (cap == CAP_LINUX_IMMUTABLE) {
+ if (seclvl > 0) {
+ rc = -EPERM;
+
+ if (cap == CAP_LINUX_IMMUTABLE)
seclvl_printk(1, KERN_WARNING, "Attempt to modify "
"the IMMUTABLE and/or APPEND extended "
"attribute on a file with the IMMUTABLE "
"and/or APPEND extended attribute set "
"denied in seclvl [%d]\n", seclvl);
- return -EPERM;
- } else if (cap == CAP_SYS_RAWIO) { // Somewhat broad...
+ else if (cap == CAP_SYS_RAWIO)
seclvl_printk(1, KERN_WARNING, "Attempt to perform "
"raw I/O while in secure level [%d] "
"denied\n", seclvl);
- return -EPERM;
- } else if (cap == CAP_NET_ADMIN) {
+ else if (cap == CAP_NET_ADMIN)
seclvl_printk(1, KERN_WARNING, "Attempt to perform "
"network administrative task while "
"in secure level [%d] denied\n", seclvl);
- return -EPERM;
- } else if (cap == CAP_SETUID) {
+ else if (cap == CAP_SETUID)
seclvl_printk(1, KERN_WARNING, "Attempt to setuid "
"while in secure level [%d] denied\n",
seclvl);
- return -EPERM;
- } else if (cap == CAP_SETGID) {
+ else if (cap == CAP_SETGID)
seclvl_printk(1, KERN_WARNING, "Attempt to setgid "
"while in secure level [%d] denied\n",
seclvl);
- } else if (cap == CAP_SYS_MODULE) {
+ else if (cap == CAP_SYS_MODULE)
seclvl_printk(1, KERN_WARNING, "Attempt to perform "
"a module operation while in secure "
"level [%d] denied\n", seclvl);
- return -EPERM;
- }
- break;
- default:
- break;
+ else
+ rc = 0;
}
- /* from dummy.c */
- if (cap_is_fs_cap(cap) ? tsk->fsuid == 0 : tsk->euid == 0)
- return 0; /* capability granted */
- seclvl_printk(1, KERN_WARNING, "Capability denied\n");
- return -EPERM; /* capability denied */
+
+ if (!rc) {
+ if (!(cap_is_fs_cap(cap) ? tsk->fsuid == 0 : tsk->euid == 0))
+ rc = -EPERM;
+ }
+
+ if (rc)
+ seclvl_printk(1, KERN_WARNING, "Capability denied\n");
+
+ return rc;
}
/**
*/
static int seclvl_settime(struct timespec *tv, struct timezone *tz)
{
- struct timespec now;
- if (seclvl > 1) {
+ if (tv && seclvl > 1) {
+ struct timespec now;
now = current_kernel_time();
if (tv->tv_sec < now.tv_sec ||
(tv->tv_sec == now.tv_sec && tv->tv_nsec < now.tv_nsec)) {
static void seclvl_file_free_security(struct file *filp)
{
struct dentry *dentry = filp->f_dentry;
- struct inode *inode = NULL;
- if (dentry) {
- inode = dentry->d_inode;
- seclvl_bd_release(inode);
- }
+ if (dentry)
+ seclvl_bd_release(dentry->d_inode);
}
/**
*/
static int seclvl_umount(struct vfsmount *mnt, int flags)
{
- if (current->pid == 1) {
- return 0;
- }
- if (seclvl == 2) {
+ if (current->pid != 1 && seclvl == 2) {
seclvl_printk(1, KERN_WARNING, "Attempt to unmount in secure "
"level %d\n", seclvl);
return -EPERM;
static int processPassword(void)
{
int rc = 0;
- hashedPassword[0] = '\0';
if (*passwd) {
+ char *p;
+
if (*sha1_passwd) {
seclvl_printk(0, KERN_ERR, "Error: Both "
"passwd and sha1_passwd "
"exclusive.\n");
return -EINVAL;
}
- if ((rc = plaintext_to_sha1(hashedPassword, passwd,
- strlen(passwd)))) {
+
+ p = kstrdup(passwd, GFP_KERNEL);
+ if (p == NULL)
+ return -ENOMEM;
+
+ if ((rc = plaintext_to_sha1(hashedPassword, p, strlen(p))))
seclvl_printk(0, KERN_ERR, "Error: SHA1 support not "
"in kernel\n");
- return rc;
- }
+
+ kfree (p);
/* All static data goes to the BSS, which zero's the
* plaintext password out for us. */
} else if (*sha1_passwd) { // Base 16
sha1_passwd[i + 2] = tmp;
}
}
- return 0;
+ return rc;
}
/**
- * 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;
+
+ dir_ino = securityfs_create_dir("seclvl", NULL);
+
+ if (IS_ERR(dir_ino))
+ return PTR_ERR(dir_ino);
+
+ seclvl_ino = securityfs_create_file("seclvl", S_IRUGO | S_IWUSR,
+ dir_ino, &seclvl, &seclvl_file_ops);
+ if (IS_ERR(seclvl_ino)) {
+ rc = PTR_ERR(seclvl_ino);
+ goto out_deldir;
}
- sysfs_create_file(&seclvl_subsys.kset.kobj, &sysfs_attr_seclvl.attr);
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 (IS_ERR(passwd_ino)) {
+ rc = PTR_ERR(passwd_ino);
+ goto out_delf;
+ }
}
- return 0;
+ return rc;
+
+out_delf:
+ securityfs_remove(seclvl_ino);
+
+out_deldir:
+ securityfs_remove(dir_ino);
+
+ return rc;
+}
+
+static void seclvlfs_unregister(void)
+{
+ securityfs_remove(seclvl_ino);
+
+ if (*passwd || *sha1_passwd)
+ securityfs_remove(passwd_ino);
+
+ securityfs_remove(dir_ino);
}
/**
static int __init seclvl_init(void)
{
int rc = 0;
+ static char once;
+
if (verbosity < 0 || verbosity > 1) {
printk(KERN_ERR "Error: bad verbosity [%d]; only 0 or 1 "
"are valid values\n", verbosity);
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);
"module parameter(s): rc = [%d]\n", rc);
goto exit;
}
+
+ if ((rc = seclvlfs_register())) {
+ seclvl_printk(0, KERN_ERR, "Error registering with sysfs\n");
+ goto exit;
+ }
/* register ourselves with the security framework */
if (register_security(&seclvl_ops)) {
seclvl_printk(0, KERN_ERR,
seclvl_printk(0, KERN_ERR, "seclvl: Failure "
"registering with primary security "
"module.\n");
+ seclvlfs_unregister();
goto exit;
} /* if primary module registered */
secondary = 1;
} /* if we registered ourselves with the security framework */
- if ((rc = doSysfsRegistrations())) {
- seclvl_printk(0, KERN_ERR, "Error registering with sysfs\n");
- goto exit;
- }
+
seclvl_printk(0, KERN_INFO, "seclvl: Successfully initialized.\n");
+
+ if (once) {
+ once = 1;
+ seclvl_printk(0, KERN_INFO, "seclvl is going away. It has been "
+ "buggy for ages. Also, be warned that "
+ "Securelevels are useless.");
+ }
exit:
- if (rc) {
+ if (rc)
printk(KERN_ERR "seclvl: Error during initialization: rc = "
"[%d]\n", rc);
- }
return rc;
}
*/
static void __exit seclvl_exit(void)
{
- sysfs_remove_file(&seclvl_subsys.kset.kobj, &sysfs_attr_seclvl.attr);
- if (*passwd || *sha1_passwd) {
- sysfs_remove_file(&seclvl_subsys.kset.kobj,
- &sysfs_attr_passwd.attr);
- }
- subsystem_unregister(&seclvl_subsys);
- if (secondary == 1) {
+ seclvlfs_unregister();
+
+ if (secondary)
mod_unreg_security(MY_NAME, &seclvl_ops);
- } else if (unregister_security(&seclvl_ops)) {
+ else if (unregister_security(&seclvl_ops))
seclvl_printk(0, KERN_INFO,
"seclvl: Failure unregistering with the "
"kernel\n");
- }
}
module_init(seclvl_init);
git://git.onelab.eu / linux-2.6.git / blobdiff