/*
* NSA Security-Enhanced Linux (SELinux) security module
*
* This file contains the SELinux hook function implementations.
*
* Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
* Chris Vance, <cvance@nai.com>
* Wayne Salamon, <wsalamon@nai.com>
* James Morris <jmorris@redhat.com>
*
* Copyright (C) 2001,2002 Networks Associates Technology, Inc.
* Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
* Eric Paris <eparis@redhat.com>
* Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
* <dgoeddel@trustedcs.com>
* Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
* Paul Moore <paul.moore@hp.com>
* Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
* Yuichi Nakamura <ynakam@hitachisoft.jp>
*
* 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.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/tracehook.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/xattr.h>
#include <linux/capability.h>
#include <linux/unistd.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/proc_fs.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/tty.h>
#include <net/icmp.h>
#include <net/ip.h> /* for local_port_range[] */
#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
#include <net/net_namespace.h>
#include <net/netlabel.h>
#include <linux/uaccess.h>
#include <asm/ioctls.h>
#include <asm/atomic.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h> /* for network interface checks */
#include <linux/netlink.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/dccp.h>
#include <linux/quota.h>
#include <linux/un.h> /* for Unix socket types */
#include <net/af_unix.h> /* for Unix socket types */
#include <linux/parser.h>
#include <linux/nfs_mount.h>
#include <net/ipv6.h>
#include <linux/hugetlb.h>
#include <linux/personality.h>
#include <linux/sysctl.h>
#include <linux/audit.h>
#include <linux/string.h>
#include <linux/selinux.h>
#include <linux/mutex.h>
#include <linux/posix-timers.h>
#include <linux/syslog.h>
#include "avc.h"
#include "objsec.h"
#include "netif.h"
#include "netnode.h"
#include "netport.h"
#include "xfrm.h"
#include "netlabel.h"
#include "audit.h"
#define NUM_SEL_MNT_OPTS 5
extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
extern struct security_operations *security_ops;
/* SECMARK reference count */
atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
int selinux_enforcing;
static int __init enforcing_setup(char *str)
{
unsigned long enforcing;
if (!strict_strtoul(str, 0, &enforcing))
selinux_enforcing = enforcing ? 1 : 0;
return 1;
}
__setup("enforcing=", enforcing_setup);
#endif
#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
static int __init selinux_enabled_setup(char *str)
{
unsigned long enabled;
if (!strict_strtoul(str, 0, &enabled))
selinux_enabled = enabled ? 1 : 0;
return 1;
}
__setup("selinux=", selinux_enabled_setup);
#else
int selinux_enabled = 1;
#endif
static struct kmem_cache *sel_inode_cache;
/**
* selinux_secmark_enabled - Check to see if SECMARK is currently enabled
*
* Description:
* This function checks the SECMARK reference counter to see if any SECMARK
* targets are currently configured, if the reference counter is greater than
* zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
* enabled, false (0) if SECMARK is disabled.
*
*/
static int selinux_secmark_enabled(void)
{
return (atomic_read(&selinux_secmark_refcount) > 0);
}
/*
* initialise the security for the init task
*/
static void cred_init_security(void)
{
struct cred *cred = (struct cred *) current->real_cred;
struct task_security_struct *tsec;
tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
if (!tsec)
panic("SELinux: Failed to initialize initial task.\n");
tsec->osid = tsec->sid = SECINITSID_KERNEL;
cred->security = tsec;
}
/*
* get the security ID of a set of credentials
*/
static inline u32 cred_sid(const struct cred *cred)
{
const struct task_security_struct *tsec;
tsec = cred->security;
return tsec->sid;
}
/*
* get the objective security ID of a task
*/
static inline u32 task_sid(const struct task_struct *task)
{
u32 sid;
rcu_read_lock();
sid = cred_sid(__task_cred(task));
rcu_read_unlock();
return sid;
}
/*
* get the subjective security ID of the current task
*/
static inline u32 current_sid(void)
{
const struct task_security_struct *tsec = current_security();
return tsec->sid;
}
/* Allocate and free functions for each kind of security blob. */
static int inode_alloc_security(struct inode *inode)
{
struct inode_security_struct *isec;
u32 sid = current_sid();
isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
if (!isec)
return -ENOMEM;
mutex_init(&isec->lock);
INIT_LIST_HEAD(&isec->list);
isec->inode = inode;
isec->sid = SECINITSID_UNLABELED;
isec->sclass = SECCLASS_FILE;
isec->task_sid = sid;
inode->i_security = isec;
return 0;
}
static void inode_free_security(struct inode *inode)
{
struct inode_security_struct *isec = inode->i_security;
struct superblock_security_struct *sbsec = inode->i_sb->s_security;
spin_lock(&sbsec->isec_lock);
if (!list_empty(&isec->list))
list_del_init(&isec->list);
spin_unlock(&sbsec->isec_lock);
inode->i_security = NULL;
kmem_cache_free(sel_inode_cache, isec);
}
static int file_alloc_security(struct file *file)
{
struct file_security_struct *fsec;
u32 sid = current_sid();
fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
if (!fsec)
return -ENOMEM;
fsec->sid = sid;
fsec->fown_sid = sid;
file->f_security = fsec;
return 0;
}
static void file_free_security(struct file *file)
{
struct file_security_struct *fsec = file->f_security;
file->f_security = NULL;
kfree(fsec);
}
static int superblock_alloc_security(struct super_block *sb)
{
struct superblock_security_struct *sbsec;
sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
if (!sbsec)
return -ENOMEM;
mutex_init(&sbsec->lock);
INIT_LIST_HEAD(&sbsec->isec_head);
spin_lock_init(&sbsec->isec_lock);
sbsec->sb = sb;
sbsec->sid = SECINITSID_UNLABELED;
sbsec->def_sid = SECINITSID_FILE;
sbsec->mntpoint_sid = SECINITSID_UNLABELED;
sb->s_security = sbsec;
return 0;
}
static void superblock_free_security(struct super_block *sb)
{
struct superblock_security_struct *sbsec = sb->s_security;
sb->s_security = NULL;
kfree(sbsec);
}
/* The security server must be initialized before
any labeling or access decisions can be provided. */
extern int ss_initialized;
/* The file system's label must be initialized prior to use. */
static const char *labeling_behaviors[6] = {
"uses xattr",
"uses transition SIDs",
"uses task SIDs",
"uses genfs_contexts",
"not configured for labeling",
"uses mountpoint labeling",
};
static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
static inline int inode_doinit(struct inode *inode)
{
return inode_doinit_with_dentry(inode, NULL);
}
enum {
Opt_error = -1,
Opt_context = 1,
Opt_fscontext = 2,
Opt_defcontext = 3,
Opt_rootcontext = 4,
Opt_labelsupport = 5,
};
static const match_table_t tokens = {
{Opt_context, CONTEXT_STR "%s"},
{Opt_fscontext, FSCONTEXT_STR "%s"},
{Opt_defcontext, DEFCONTEXT_STR "%s"},
{Opt_rootcontext, ROOTCONTEXT_STR "%s"},
{Opt_labelsupport, LABELSUPP_STR},
{Opt_error, NULL},
};
#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
static int may_context_mount_sb_relabel(u32 sid,
struct superblock_security_struct *sbsec,
const struct cred *cred)
{
const struct task_security_struct *tsec = cred->security;
int rc;
rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
FILESYSTEM__RELABELFROM, NULL);
if (rc)
return rc;
rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
FILESYSTEM__RELABELTO, NULL);
return rc;
}
static int may_context_mount_inode_relabel(u32 sid,
struct superblock_security_struct *sbsec,
const struct cred *cred)
{
const struct task_security_struct *tsec = cred->security;
int rc;
rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
FILESYSTEM__RELABELFROM, NULL);
if (rc)
return rc;
rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
FILESYSTEM__ASSOCIATE, NULL);
return rc;
}
static int sb_finish_set_opts(struct super_block *sb)
{
struct superblock_security_struct *sbsec = sb->s_security;
struct dentry *root = sb->s_root;
struct inode *root_inode = root->d_inode;
int rc = 0;
if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
/* Make sure that the xattr handler exists and that no
error other than -ENODATA is returned by getxattr on
the root directory. -ENODATA is ok, as this may be
the first boot of the SELinux kernel before we have
assigned xattr values to the filesystem. */
if (!root_inode->i_op->getxattr) {
printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
"xattr support\n", sb->s_id, sb->s_type->name);
rc = -EOPNOTSUPP;
goto out;
}
rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
if (rc < 0 && rc != -ENODATA) {
if (rc == -EOPNOTSUPP)
printk(KERN_WARNING "SELinux: (dev %s, type "
"%s) has no security xattr handler\n",
sb->s_id, sb->s_type->name);
else
printk(KERN_WARNING "SELinux: (dev %s, type "
"%s) getxattr errno %d\n", sb->s_id,
sb->s_type->name, -rc);
goto out;
}
}
sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
sb->s_id, sb->s_type->name);
else
printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
sb->s_id, sb->s_type->name,
labeling_behaviors[sbsec->behavior-1]);
if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
sbsec->behavior == SECURITY_FS_USE_NONE ||
sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
sbsec->flags &= ~SE_SBLABELSUPP;
/* Special handling for sysfs. Is genfs but also has setxattr handler*/
if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
sbsec->flags |= SE_SBLABELSUPP;
/* Initialize the root inode. */
rc = inode_doinit_with_dentry(root_inode, root);
/* Initialize any other inodes associated with the superblock, e.g.
inodes created prior to initial policy load or inodes created
during get_sb by a pseudo filesystem that directly
populates itself. */
spin_lock(&sbsec->isec_lock);
next_inode:
if (!list_empty(&sbsec->isec_head)) {
struct inode_security_struct *isec =
list_entry(sbsec->isec_head.next,
struct inode_security_struct, list);
struct inode *inode = isec->inode;
spin_unlock(&sbsec->isec_lock);
inode = igrab(inode);
if (inode) {
if (!IS_PRIVATE(inode))
inode_doinit(inode);
iput(inode);
}
spin_lock(&sbsec->isec_lock);
list_del_init(&isec->list);
goto next_inode;
}
spin_unlock(&sbsec->isec_lock);
out:
return rc;
}
/*
* This function should allow an FS to ask what it's mount security
* options were so it can use those later for submounts, displaying
* mount options, or whatever.
*/
static int selinux_get_mnt_opts(const struct super_block *sb,
struct security_mnt_opts *opts)
{
int rc = 0, i;
struct superblock_security_struct *sbsec = sb->s_security;
char *context = NULL;
u32 len;
char tmp;
security_init_mnt_opts(opts);
if (!(sbsec->flags & SE_SBINITIALIZED))
return -EINVAL;
if (!ss_initialized)
return -EINVAL;
tmp = sbsec->flags & SE_MNTMASK;
/* count the number of mount options for this sb */
for (i = 0; i < 8; i++) {
if (tmp & 0x01)
opts->num_mnt_opts++;
tmp >>= 1;
}
/* Check if the Label support flag is set */
if (sbsec->flags & SE_SBLABELSUPP)
opts->num_mnt_opts++;
opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
if (!opts->mnt_opts) {
rc = -ENOMEM;
goto out_free;
}
opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
if (!opts->mnt_opts_flags) {
rc = -ENOMEM;
goto out_free;
}
i = 0;
if (sbsec->flags & FSCONTEXT_MNT) {
rc = security_sid_to_context(sbsec->sid, &context, &len);
if (rc)
goto out_free;
opts->mnt_opts[i] = context;
opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
}
if (sbsec->flags & CONTEXT_MNT) {
rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
if (rc)
goto out_free;
opts->mnt_opts[i] = context;
opts->mnt_opts_flags[i++] = CONTEXT_MNT;
}
if (sbsec->flags & DEFCONTEXT_MNT) {
rc = security_sid_to_context(sbsec->def_sid, &context, &len);
if (rc)
goto out_free;
opts->mnt_opts[i] = context;
opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
}
if (sbsec->flags & ROOTCONTEXT_MNT) {
struct inode *root = sbsec->sb->s_root->d_inode;
struct inode_security_struct *isec = root->i_security;
rc = security_sid_to_context(isec->sid, &context, &len);
if (rc)
goto out_free;
opts->mnt_opts[i] = context;
opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
}
if (sbsec->flags & SE_SBLABELSUPP) {
opts->mnt_opts[i] = NULL;
opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
}
BUG_ON(i != opts->num_mnt_opts);
return 0;
out_free:
security_free_mnt_opts(opts);
return rc;
}
static int bad_option(struct superblock_security_struct *sbsec, char flag,
u32 old_sid, u32 new_sid)
{
char mnt_flags = sbsec->flags & SE_MNTMASK;
/* check if the old mount command had the same options */
if (sbsec->flags & SE_SBINITIALIZED)
if (!(sbsec->flags & flag) ||
(old_sid != new_sid))
return 1;
/* check if we were passed the same options twice,
* aka someone passed context=a,context=b
*/
if (!(sbsec->flags & SE_SBINITIALIZED))
if (mnt_flags & flag)
return 1;
return 0;
}
/*
* Allow filesystems with binary mount data to explicitly set mount point
* labeling information.
*/
static int selinux_set_mnt_opts(struct super_block *sb,
struct security_mnt_opts *opts)
{
const struct cred *cred = current_cred();
int rc = 0, i;
struct superblock_security_struct *sbsec = sb->s_security;
const char *name = sb->s_type->name;
struct inode *inode = sbsec->sb->s_root->d_inode;
struct inode_security_struct *root_isec = inode->i_security;
u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
u32 defcontext_sid = 0;
char **mount_options = opts->mnt_opts;
int *flags = opts->mnt_opts_flags;
int num_opts = opts->num_mnt_opts;
mutex_lock(&sbsec->lock);
if (!ss_initialized) {
if (!num_opts) {
/* Defer initialization until selinux_complete_init,
after the initial policy is loaded and the security
server is ready to handle calls. */
goto out;
}
rc = -EINVAL;
printk(KERN_WARNING "SELinux: Unable to set superblock options "
"before the security server is initialized\n");
goto out;
}
/*
* Binary mount data FS will come through this function twice. Once
* from an explicit call and once from the generic calls from the vfs.
* Since the generic VFS calls will not contain any security mount data
* we need to skip the double mount verification.
*
* This does open a hole in which we will not notice if the first
* mount using this sb set explict options and a second mount using
* this sb does not set any security options. (The first options
* will be used for both mounts)
*/
if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
&& (num_opts == 0))
goto out;
/*
* parse the mount options, check if they are valid sids.
* also check if someone is trying to mount the same sb more
* than once with different security options.
*/
for (i = 0; i < num_opts; i++) {
u32 sid;
if (flags[i] == SE_SBLABELSUPP)
continue;
rc = security_context_to_sid(mount_options[i],
strlen(mount_options[i]), &sid);
if (rc) {
printk(KERN_WARNING "SELinux: security_context_to_sid"
"(%s) failed for (dev %s, type %s) errno=%d\n",
mount_options[i], sb->s_id, name, rc);
goto out;
}
switch (flags[i]) {
case FSCONTEXT_MNT:
fscontext_sid = sid;
if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
fscontext_sid))
goto out_double_mount;
sbsec->flags |= FSCONTEXT_MNT;
break;
case CONTEXT_MNT:
context_sid = sid;
if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
context_sid))
goto out_double_mount;
sbsec->flags |= CONTEXT_MNT;
break;
case ROOTCONTEXT_MNT:
rootcontext_sid = sid;
if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
rootcontext_sid))
goto out_double_mount;
sbsec->flags |= ROOTCONTEXT_MNT;
break;
case DEFCONTEXT_MNT:
defcontext_sid = sid;
if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
defcontext_sid))
goto out_double_mount;
sbsec->flags |= DEFCONTEXT_MNT;
break;
default:
rc = -EINVAL;
goto out;
}
}
if (sbsec->flags & SE_SBINITIALIZED) {
/* previously mounted with options, but not on this attempt? */
if ((sbsec->flags & SE_MNTMASK) && !num_opts)
goto out_double_mount;
rc = 0;
goto out;
}
if (strcmp(sb->s_type->name, "proc") == 0)
sbsec->flags |= SE_SBPROC;
/* Determine the labeling behavior to use for this filesystem type. */
rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
if (rc) {
printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
__func__, sb->s_type->name, rc);
goto out;
}
/* sets the context of the superblock for the fs being mounted. */
if (fscontext_sid) {
rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
if (rc)
goto out;
sbsec->sid = fscontext_sid;
}
/*
* Switch to using mount point labeling behavior.
* sets the label used on all file below the mountpoint, and will set
* the superblock context if not already set.
*/
if (context_sid) {
if (!fscontext_sid) {
rc = may_context_mount_sb_relabel(context_sid, sbsec,
cred);
if (rc)
goto out;
sbsec->sid = context_sid;
} else {
rc = may_context_mount_inode_relabel(context_sid, sbsec,
cred);
if (rc)
goto out;
}
if (!rootcontext_sid)
rootcontext_sid = context_sid;
sbsec->mntpoint_sid = context_sid;
sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
}
if (rootcontext_sid) {
rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
cred);
if (rc)
goto out;
root_isec->sid = rootcontext_sid;
root_isec->initialized = 1;
}
if (defcontext_sid) {
if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
rc = -EINVAL;
printk(KERN_WARNING "SELinux: defcontext option is "
"invalid for this filesystem type\n");
goto out;
}
if (defcontext_sid != sbsec->def_sid) {
rc = may_context_mount_inode_relabel(defcontext_sid,
sbsec, cred);
if (rc)
goto out;
}
sbsec->def_sid = defcontext_sid;
}
rc = sb_finish_set_opts(sb);
out:
mutex_unlock(&sbsec->lock);
return rc;
out_double_mount:
rc = -EINVAL;
printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
"security settings for (dev %s, type %s)\n", sb->s_id, name);
goto out;
}
static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
struct super_block *newsb)
{
const struct superblock_security_struct *oldsbsec = oldsb->s_security;
struct superblock_security_struct *newsbsec = newsb->s_security;
int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
int set_context = (oldsbsec->flags & CONTEXT_MNT);
int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
/*
* if the parent was able to be mounted it clearly had no special lsm
* mount options. thus we can safely deal with this superblock later
*/
if (!ss_initialized)
return;
/* how can we clone if the old one wasn't set up?? */
BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
/* if fs is reusing a sb, just let its options stand... */
if (newsbsec->flags & SE_SBINITIALIZED)
return;
mutex_lock(&newsbsec->lock);
newsbsec->flags = oldsbsec->flags;
newsbsec->sid = oldsbsec->sid;
newsbsec->def_sid = oldsbsec->def_sid;
newsbsec->behavior = oldsbsec->behavior;
if (set_context) {
u32 sid = oldsbsec->mntpoint_sid;
if (!set_fscontext)
newsbsec->sid = sid;
if (!set_rootcontext) {
struct inode *newinode = newsb->s_root->d_inode;
struct inode_security_struct *newisec = newinode->i_security;
newisec->sid = sid;
}
newsbsec->mntpoint_sid = sid;
}
if (set_rootcontext) {
const struct inode *oldinode = oldsb->s_root->d_inode;
const struct inode_security_struct *oldisec = oldinode->i_security;
struct inode *newinode = newsb->s_root->d_inode;
struct inode_security_struct *newisec = newinode->i_security;
newisec->sid = oldisec->sid;
}
sb_finish_set_opts(newsb);
mutex_unlock(&newsbsec->lock);
}
static int selinux_parse_opts_str(char *options,
struct security_mnt_opts *opts)
{
char *p;
char *context = NULL, *defcontext = NULL;
char *fscontext = NULL, *rootcontext = NULL;
int rc, num_mnt_opts = 0;
opts->num_mnt_opts = 0;
/* Standard string-based options. */
while ((p = strsep(&options, "|")) != NULL) {
int token;
substring_t args[MAX_OPT_ARGS];
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_context:
if (context || defcontext) {
rc = -EINVAL;
printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
goto out_err;
}
context = match_strdup(&args[0]);
if (!context) {
rc = -ENOMEM;
goto out_err;
}
break;
case Opt_fscontext:
if (fscontext) {
rc = -EINVAL;
printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
goto out_err;
}
fscontext = match_strdup(&args[0]);
if (!fscontext) {
rc = -ENOMEM;
goto out_err;
}
break;
case Opt_rootcontext:
if (rootcontext) {
rc = -EINVAL;
printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
goto out_err;
}
rootcontext = match_strdup(&args[0]);
if (!rootcontext) {
rc = -ENOMEM;
goto out_err;
}
break;
case Opt_defcontext:
if (context || defcontext) {
rc = -EINVAL;
printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
goto out_err;
}
defcontext = match_strdup(&args[0]);
if (!defcontext) {
rc = -ENOMEM;
goto out_err;
}
break;
case Opt_labelsupport:
break;
default:
rc = -EINVAL;
printk(KERN_WARNING "SELinux: unknown mount option\n");
goto out_err;
}
}
rc = -ENOMEM;
opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
if (!opts->mnt_opts)
goto out_err;
opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
if (!opts->mnt_opts_flags) {
kfree(opts->mnt_opts);
goto out_err;
}
if (fscontext) {
opts->mnt_opts[num_mnt_opts] = fscontext;
opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
}
if (context) {
opts->mnt_opts[num_mnt_opts] = context;
opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
}
if (rootcontext) {
opts->mnt_opts[num_mnt_opts] = rootcontext;
opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
}
if (defcontext) {
opts->mnt_opts[num_mnt_opts] = defcontext;
opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
}
opts->num_mnt_opts = num_mnt_opts;
return 0;
out_err:
kfree(context);
kfree(defcontext);
kfree(fscontext);
kfree(rootcontext);
return rc;
}
/*
* string mount options parsing and call set the sbsec
*/
static int superblock_doinit(struct super_block *sb, void *data)
{
int rc = 0;
char *options = data;
struct security_mnt_opts opts;
security_init_mnt_opts(&opts);
if (!data)
goto out;
BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
rc = selinux_parse_opts_str(options, &opts);
if (rc)
goto out_err;
out:
rc = selinux_set_mnt_opts(sb, &opts);
out_err:
security_free_mnt_opts(&opts);
return rc;
}
static void selinux_write_opts(struct seq_file *m,
struct security_mnt_opts *opts)
{
int i;
char *prefix;
for (i = 0; i < opts->num_mnt_opts; i++) {
char *has_comma;
if (opts->mnt_opts[i])
has_comma = strchr(opts->mnt_opts[i], ',');
else
has_comma = NULL;
switch (opts->mnt_opts_flags[i]) {
case CONTEXT_MNT:
prefix = CONTEXT_STR;
break;
case FSCONTEXT_MNT:
prefix = FSCONTEXT_STR;
break;
case ROOTCONTEXT_MNT:
prefix = ROOTCONTEXT_STR;
break;
case DEFCONTEXT_MNT:
prefix = DEFCONTEXT_STR;
break;
case SE_SBLABELSUPP:
seq_putc(m, ',');
seq_puts(m, LABELSUPP_STR);
continue;
default:
BUG();
};
/* we need a comma before each option */
seq_putc(m, ',');
seq_puts(m, prefix);
if (has_comma)
seq_putc(m, '\"');
seq_puts(m, opts->mnt_opts[i]);
if (has_comma)
seq_putc(m, '\"');
}
}
static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
{
struct security_mnt_opts opts;
int rc;
rc = selinux_get_mnt_opts(sb, &opts);
if (rc) {
/* before policy load we may get EINVAL, don't show anything */
if (rc == -EINVAL)
rc = 0;
return rc;
}
selinux_write_opts(m, &opts);
security_free_mnt_opts(&opts);
return rc;
}
static inline u16 inode_mode_to_security_class(umode_t mode)
{
switch (mode & S_IFMT) {
case S_IFSOCK:
return SECCLASS_SOCK_FILE;
case S_IFLNK:
return SECCLASS_LNK_FILE;
case S_IFREG:
return SECCLASS_FILE;
case S_IFBLK:
return SECCLASS_BLK_FILE;
case S_IFDIR:
return SECCLASS_DIR;
case S_IFCHR:
return SECCLASS_CHR_FILE;
case S_IFIFO:
return SECCLASS_FIFO_FILE;
}
return SECCLASS_FILE;
}
static inline int default_protocol_stream(int protocol)
{
return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
}
static inline int default_protocol_dgram(int protocol)
{
return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
}
static inline u16 socket_type_to_security_class(int family, int type, int protocol)
{
switch (family) {
case PF_UNIX:
switch (type) {
case SOCK_STREAM:
case SOCK_SEQPACKET:
return SECCLASS_UNIX_STREAM_SOCKET;
case SOCK_DGRAM:
return SECCLASS_UNIX_DGRAM_SOCKET;
}
break;
case PF_INET:
case PF_INET6:
switch (type) {
case SOCK_STREAM:
if (default_protocol_stream(protocol))
return SECCLASS_TCP_SOCKET;
else
return SECCLASS_RAWIP_SOCKET;
case SOCK_DGRAM:
if (default_protocol_dgram(protocol))
return SECCLASS_UDP_SOCKET;
else
return SECCLASS_RAWIP_SOCKET;
case SOCK_DCCP:
return SECCLASS_DCCP_SOCKET;
default:
return SECCLASS_RAWIP_SOCKET;
}
break;
case PF_NETLINK:
switch (protocol) {
case NETLINK_ROUTE:
return SECCLASS_NETLINK_ROUTE_SOCKET;
case NETLINK_FIREWALL:
return SECCLASS_NETLINK_FIREWALL_SOCKET;
case NETLINK_INET_DIAG:
return SECCLASS_NETLINK_TCPDIAG_SOCKET;
case NETLINK_NFLOG:
return SECCLASS_NETLINK_NFLOG_SOCKET;
case NETLINK_XFRM:
return SECCLASS_NETLINK_XFRM_SOCKET;
case NETLINK_SELINUX:
return SECCLASS_NETLINK_SELINUX_SOCKET;
case NETLINK_AUDIT:
return SECCLASS_NETLINK_AUDIT_SOCKET;
case NETLINK_IP6_FW:
return SECCLASS_NETLINK_IP6FW_SOCKET;
case NETLINK_DNRTMSG:
return SECCLASS_NETLINK_DNRT_SOCKET;
case NETLINK_KOBJECT_UEVENT:
return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
default:
return SECCLASS_NETLINK_SOCKET;
}
case PF_PACKET:
return SECCLASS_PACKET_SOCKET;
case PF_KEY:
return SECCLASS_KEY_SOCKET;
case PF_APPLETALK:
return SECCLASS_APPLETALK_SOCKET;
}
return SECCLASS_SOCKET;
}
#ifdef CONFIG_PROC_FS
static int selinux_proc_get_sid(struct proc_dir_entry *de,
u16 tclass,
u32 *sid)
{
int buflen, rc;
char *buffer, *path, *end;
buffer = (char *)__get_free_page(GFP_KERNEL);
if (!buffer)
return -ENOMEM;
buflen = PAGE_SIZE;
end = buffer+buflen;
*--end = '\0';
buflen--;
path = end-1;
*path = '/';
while (de && de != de->parent) {
buflen -= de->namelen + 1;
if (buflen < 0)
break;
end -= de->namelen;
memcpy(end, de->name, de->namelen);
*--end = '/';
path = end;
de = de->parent;
}
rc = security_genfs_sid("proc", path, tclass, sid);
free_page((unsigned long)buffer);
return rc;
}
#else
static int selinux_proc_get_sid(struct proc_dir_entry *de,
u16 tclass,
u32 *sid)
{
return -EINVAL;
}
#endif
/* The inode's security attributes must be initialized before first use. */
static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
{
struct superblock_security_struct *sbsec = NULL;
struct inode_security_struct *isec = inode->i_security;
u32 sid;
struct dentry *dentry;
#define INITCONTEXTLEN 255
char *context = NULL;
unsigned len = 0;
int rc = 0;
if (isec->initialized)
goto out;
mutex_lock(&isec->lock);
if (isec->initialized)
goto out_unlock;
sbsec = inode->i_sb->s_security;
if (!(sbsec->flags & SE_SBINITIALIZED)) {
/* Defer initialization until selinux_complete_init,
after the initial policy is loaded and the security
server is ready to handle calls. */
spin_lock(&sbsec->isec_lock);
if (list_empty(&isec->list))
list_add(&isec->list, &sbsec->isec_head);
spin_unlock(&sbsec->isec_lock);
goto out_unlock;
}
switch (sbsec->behavior) {
case SECURITY_FS_USE_XATTR:
if (!inode->i_op->getxattr) {
isec->sid = sbsec->def_sid;
break;
}
/* Need a dentry, since the xattr API requires one.
Life would be simpler if we could just pass the inode. */
if (opt_dentry) {
/* Called from d_instantiate or d_splice_alias. */
dentry = dget(opt_dentry);
} else {
/* Called from selinux_complete_init, try to find a dentry. */
dentry = d_find_alias(inode);
}
if (!dentry) {
/*
* this is can be hit on boot when a file is accessed
* before the policy is loaded. When we load policy we
* may find inodes that have no dentry on the
* sbsec->isec_head list. No reason to complain as these
* will get fixed up the next time we go through
* inode_doinit with a dentry, before these inodes could
* be used again by userspace.
*/
goto out_unlock;
}
len = INITCONTEXTLEN;
context = kmalloc(len+1, GFP_NOFS);
if (!context) {
rc = -ENOMEM;
dput(dentry);
goto out_unlock;
}
context[len] = '\0';
rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
context, len);
if (rc == -ERANGE) {
kfree(context);
/* Need a larger buffer. Query for the right size. */
rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
NULL, 0);
if (rc < 0) {
dput(dentry);
goto out_unlock;
}
len = rc;
context = kmalloc(len+1, GFP_NOFS);
if (!context) {
rc = -ENOMEM;
dput(dentry);
goto out_unlock;
}
context[len] = '\0';
rc = inode->i_op->getxattr(dentry,
XATTR_NAME_SELINUX,
context, len);
}
dput(dentry);
if (rc < 0) {
if (rc != -ENODATA) {
|