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linux-zen-server/security/smack/smack_lsm.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Simplified MAC Kernel (smack) security module
*
* This file contains the smack hook function implementations.
*
* Authors:
* Casey Schaufler <casey@schaufler-ca.com>
* Jarkko Sakkinen <jarkko.sakkinen@intel.com>
*
* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
* Paul Moore <paul@paul-moore.com>
* Copyright (C) 2010 Nokia Corporation
* Copyright (C) 2011 Intel Corporation.
*/
#include <linux/xattr.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/stat.h>
#include <linux/kd.h>
#include <asm/ioctls.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/dccp.h>
#include <linux/icmpv6.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <net/cipso_ipv4.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <linux/audit.h>
#include <linux/magic.h>
#include <linux/dcache.h>
#include <linux/personality.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/binfmts.h>
#include <linux/parser.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/watch_queue.h>
#include <linux/io_uring.h>
#include "smack.h"
#define TRANS_TRUE "TRUE"
#define TRANS_TRUE_SIZE 4
#define SMK_CONNECTING 0
#define SMK_RECEIVING 1
#define SMK_SENDING 2
#ifdef SMACK_IPV6_PORT_LABELING
static DEFINE_MUTEX(smack_ipv6_lock);
static LIST_HEAD(smk_ipv6_port_list);
#endif
struct kmem_cache *smack_rule_cache;
int smack_enabled __initdata;
#define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
static struct {
const char *name;
int len;
int opt;
} smk_mount_opts[] = {
{"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault},
A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute)
};
#undef A
static int match_opt_prefix(char *s, int l, char **arg)
{
int i;
for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) {
size_t len = smk_mount_opts[i].len;
if (len > l || memcmp(s, smk_mount_opts[i].name, len))
continue;
if (len == l || s[len] != '=')
continue;
*arg = s + len + 1;
return smk_mount_opts[i].opt;
}
return Opt_error;
}
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static char *smk_bu_mess[] = {
"Bringup Error", /* Unused */
"Bringup", /* SMACK_BRINGUP_ALLOW */
"Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */
"Unconfined Object", /* SMACK_UNCONFINED_OBJECT */
};
static void smk_bu_mode(int mode, char *s)
{
int i = 0;
if (mode & MAY_READ)
s[i++] = 'r';
if (mode & MAY_WRITE)
s[i++] = 'w';
if (mode & MAY_EXEC)
s[i++] = 'x';
if (mode & MAY_APPEND)
s[i++] = 'a';
if (mode & MAY_TRANSMUTE)
s[i++] = 't';
if (mode & MAY_LOCK)
s[i++] = 'l';
if (i == 0)
s[i++] = '-';
s[i] = '\0';
}
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_note(char *note, struct smack_known *sskp,
struct smack_known *oskp, int mode, int rc)
{
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
sskp->smk_known, oskp->smk_known, acc, note);
return 0;
}
#else
#define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_current(char *note, struct smack_known *oskp,
int mode, int rc)
{
struct task_smack *tsp = smack_cred(current_cred());
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
tsp->smk_task->smk_known, oskp->smk_known,
acc, current->comm, note);
return 0;
}
#else
#define smk_bu_current(note, oskp, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_task(struct task_struct *otp, int mode, int rc)
{
struct task_smack *tsp = smack_cred(current_cred());
struct smack_known *smk_task = smk_of_task_struct_obj(otp);
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
tsp->smk_task->smk_known, smk_task->smk_known, acc,
current->comm, otp->comm);
return 0;
}
#else
#define smk_bu_task(otp, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_inode(struct inode *inode, int mode, int rc)
{
struct task_smack *tsp = smack_cred(current_cred());
struct inode_smack *isp = smack_inode(inode);
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (isp->smk_flags & SMK_INODE_IMPURE)
pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
inode->i_sb->s_id, inode->i_ino, current->comm);
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
if (rc == SMACK_UNCONFINED_SUBJECT &&
(mode & (MAY_WRITE | MAY_APPEND)))
isp->smk_flags |= SMK_INODE_IMPURE;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, current->comm);
return 0;
}
#else
#define smk_bu_inode(inode, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_file(struct file *file, int mode, int rc)
{
struct task_smack *tsp = smack_cred(current_cred());
struct smack_known *sskp = tsp->smk_task;
struct inode *inode = file_inode(file);
struct inode_smack *isp = smack_inode(inode);
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (isp->smk_flags & SMK_INODE_IMPURE)
pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
inode->i_sb->s_id, inode->i_ino, current->comm);
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, file,
current->comm);
return 0;
}
#else
#define smk_bu_file(file, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_credfile(const struct cred *cred, struct file *file,
int mode, int rc)
{
struct task_smack *tsp = smack_cred(cred);
struct smack_known *sskp = tsp->smk_task;
struct inode *inode = file_inode(file);
struct inode_smack *isp = smack_inode(inode);
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (isp->smk_flags & SMK_INODE_IMPURE)
pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
inode->i_sb->s_id, inode->i_ino, current->comm);
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, file,
current->comm);
return 0;
}
#else
#define smk_bu_credfile(cred, file, mode, RC) (RC)
#endif
/**
* smk_fetch - Fetch the smack label from a file.
* @name: type of the label (attribute)
* @ip: a pointer to the inode
* @dp: a pointer to the dentry
*
* Returns a pointer to the master list entry for the Smack label,
* NULL if there was no label to fetch, or an error code.
*/
static struct smack_known *smk_fetch(const char *name, struct inode *ip,
struct dentry *dp)
{
int rc;
char *buffer;
struct smack_known *skp = NULL;
if (!(ip->i_opflags & IOP_XATTR))
return ERR_PTR(-EOPNOTSUPP);
buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS);
if (buffer == NULL)
return ERR_PTR(-ENOMEM);
rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
if (rc < 0)
skp = ERR_PTR(rc);
else if (rc == 0)
skp = NULL;
else
skp = smk_import_entry(buffer, rc);
kfree(buffer);
return skp;
}
/**
* init_inode_smack - initialize an inode security blob
* @inode: inode to extract the info from
* @skp: a pointer to the Smack label entry to use in the blob
*
*/
static void init_inode_smack(struct inode *inode, struct smack_known *skp)
{
struct inode_smack *isp = smack_inode(inode);
isp->smk_inode = skp;
isp->smk_flags = 0;
}
/**
* init_task_smack - initialize a task security blob
* @tsp: blob to initialize
* @task: a pointer to the Smack label for the running task
* @forked: a pointer to the Smack label for the forked task
*
*/
static void init_task_smack(struct task_smack *tsp, struct smack_known *task,
struct smack_known *forked)
{
tsp->smk_task = task;
tsp->smk_forked = forked;
INIT_LIST_HEAD(&tsp->smk_rules);
INIT_LIST_HEAD(&tsp->smk_relabel);
mutex_init(&tsp->smk_rules_lock);
}
/**
* smk_copy_rules - copy a rule set
* @nhead: new rules header pointer
* @ohead: old rules header pointer
* @gfp: type of the memory for the allocation
*
* Returns 0 on success, -ENOMEM on error
*/
static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
gfp_t gfp)
{
struct smack_rule *nrp;
struct smack_rule *orp;
int rc = 0;
list_for_each_entry_rcu(orp, ohead, list) {
nrp = kmem_cache_zalloc(smack_rule_cache, gfp);
if (nrp == NULL) {
rc = -ENOMEM;
break;
}
*nrp = *orp;
list_add_rcu(&nrp->list, nhead);
}
return rc;
}
/**
* smk_copy_relabel - copy smk_relabel labels list
* @nhead: new rules header pointer
* @ohead: old rules header pointer
* @gfp: type of the memory for the allocation
*
* Returns 0 on success, -ENOMEM on error
*/
static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
gfp_t gfp)
{
struct smack_known_list_elem *nklep;
struct smack_known_list_elem *oklep;
list_for_each_entry(oklep, ohead, list) {
nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
if (nklep == NULL) {
smk_destroy_label_list(nhead);
return -ENOMEM;
}
nklep->smk_label = oklep->smk_label;
list_add(&nklep->list, nhead);
}
return 0;
}
/**
* smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
* @mode: input mode in form of PTRACE_MODE_*
*
* Returns a converted MAY_* mode usable by smack rules
*/
static inline unsigned int smk_ptrace_mode(unsigned int mode)
{
if (mode & PTRACE_MODE_ATTACH)
return MAY_READWRITE;
if (mode & PTRACE_MODE_READ)
return MAY_READ;
return 0;
}
/**
* smk_ptrace_rule_check - helper for ptrace access
* @tracer: tracer process
* @tracee_known: label entry of the process that's about to be traced
* @mode: ptrace attachment mode (PTRACE_MODE_*)
* @func: name of the function that called us, used for audit
*
* Returns 0 on access granted, -error on error
*/
static int smk_ptrace_rule_check(struct task_struct *tracer,
struct smack_known *tracee_known,
unsigned int mode, const char *func)
{
int rc;
struct smk_audit_info ad, *saip = NULL;
struct task_smack *tsp;
struct smack_known *tracer_known;
const struct cred *tracercred;
if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, tracer);
saip = &ad;
}
rcu_read_lock();
tracercred = __task_cred(tracer);
tsp = smack_cred(tracercred);
tracer_known = smk_of_task(tsp);
if ((mode & PTRACE_MODE_ATTACH) &&
(smack_ptrace_rule == SMACK_PTRACE_EXACT ||
smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
if (tracer_known->smk_known == tracee_known->smk_known)
rc = 0;
else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
rc = -EACCES;
else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred))
rc = 0;
else
rc = -EACCES;
if (saip)
smack_log(tracer_known->smk_known,
tracee_known->smk_known,
0, rc, saip);
rcu_read_unlock();
return rc;
}
/* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
rcu_read_unlock();
return rc;
}
/*
* LSM hooks.
* We he, that is fun!
*/
/**
* smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
* @ctp: child task pointer
* @mode: ptrace attachment mode (PTRACE_MODE_*)
*
* Returns 0 if access is OK, an error code otherwise
*
* Do the capability checks.
*/
static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
{
struct smack_known *skp;
skp = smk_of_task_struct_obj(ctp);
return smk_ptrace_rule_check(current, skp, mode, __func__);
}
/**
* smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
* @ptp: parent task pointer
*
* Returns 0 if access is OK, an error code otherwise
*
* Do the capability checks, and require PTRACE_MODE_ATTACH.
*/
static int smack_ptrace_traceme(struct task_struct *ptp)
{
struct smack_known *skp;
skp = smk_of_task(smack_cred(current_cred()));
return smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
}
/**
* smack_syslog - Smack approval on syslog
* @typefrom_file: unused
*
* Returns 0 on success, error code otherwise.
*/
static int smack_syslog(int typefrom_file)
{
int rc = 0;
struct smack_known *skp = smk_of_current();
if (smack_privileged(CAP_MAC_OVERRIDE))
return 0;
if (smack_syslog_label != NULL && smack_syslog_label != skp)
rc = -EACCES;
return rc;
}
/*
* Superblock Hooks.
*/
/**
* smack_sb_alloc_security - allocate a superblock blob
* @sb: the superblock getting the blob
*
* Returns 0 on success or -ENOMEM on error.
*/
static int smack_sb_alloc_security(struct super_block *sb)
{
struct superblock_smack *sbsp = smack_superblock(sb);
sbsp->smk_root = &smack_known_floor;
sbsp->smk_default = &smack_known_floor;
sbsp->smk_floor = &smack_known_floor;
sbsp->smk_hat = &smack_known_hat;
/*
* SMK_SB_INITIALIZED will be zero from kzalloc.
*/
return 0;
}
struct smack_mnt_opts {
const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute;
};
static void smack_free_mnt_opts(void *mnt_opts)
{
struct smack_mnt_opts *opts = mnt_opts;
kfree(opts->fsdefault);
kfree(opts->fsfloor);
kfree(opts->fshat);
kfree(opts->fsroot);
kfree(opts->fstransmute);
kfree(opts);
}
static int smack_add_opt(int token, const char *s, void **mnt_opts)
{
struct smack_mnt_opts *opts = *mnt_opts;
if (!opts) {
opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
if (!opts)
return -ENOMEM;
*mnt_opts = opts;
}
if (!s)
return -ENOMEM;
switch (token) {
case Opt_fsdefault:
if (opts->fsdefault)
goto out_opt_err;
opts->fsdefault = s;
break;
case Opt_fsfloor:
if (opts->fsfloor)
goto out_opt_err;
opts->fsfloor = s;
break;
case Opt_fshat:
if (opts->fshat)
goto out_opt_err;
opts->fshat = s;
break;
case Opt_fsroot:
if (opts->fsroot)
goto out_opt_err;
opts->fsroot = s;
break;
case Opt_fstransmute:
if (opts->fstransmute)
goto out_opt_err;
opts->fstransmute = s;
break;
}
return 0;
out_opt_err:
pr_warn("Smack: duplicate mount options\n");
return -EINVAL;
}
/**
* smack_fs_context_dup - Duplicate the security data on fs_context duplication
* @fc: The new filesystem context.
* @src_fc: The source filesystem context being duplicated.
*
* Returns 0 on success or -ENOMEM on error.
*/
static int smack_fs_context_dup(struct fs_context *fc,
struct fs_context *src_fc)
{
struct smack_mnt_opts *dst, *src = src_fc->security;
if (!src)
return 0;
fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
if (!fc->security)
return -ENOMEM;
dst = fc->security;
if (src->fsdefault) {
dst->fsdefault = kstrdup(src->fsdefault, GFP_KERNEL);
if (!dst->fsdefault)
return -ENOMEM;
}
if (src->fsfloor) {
dst->fsfloor = kstrdup(src->fsfloor, GFP_KERNEL);
if (!dst->fsfloor)
return -ENOMEM;
}
if (src->fshat) {
dst->fshat = kstrdup(src->fshat, GFP_KERNEL);
if (!dst->fshat)
return -ENOMEM;
}
if (src->fsroot) {
dst->fsroot = kstrdup(src->fsroot, GFP_KERNEL);
if (!dst->fsroot)
return -ENOMEM;
}
if (src->fstransmute) {
dst->fstransmute = kstrdup(src->fstransmute, GFP_KERNEL);
if (!dst->fstransmute)
return -ENOMEM;
}
return 0;
}
static const struct fs_parameter_spec smack_fs_parameters[] = {
fsparam_string("smackfsdef", Opt_fsdefault),
fsparam_string("smackfsdefault", Opt_fsdefault),
fsparam_string("smackfsfloor", Opt_fsfloor),
fsparam_string("smackfshat", Opt_fshat),
fsparam_string("smackfsroot", Opt_fsroot),
fsparam_string("smackfstransmute", Opt_fstransmute),
{}
};
/**
* smack_fs_context_parse_param - Parse a single mount parameter
* @fc: The new filesystem context being constructed.
* @param: The parameter.
*
* Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on
* error.
*/
static int smack_fs_context_parse_param(struct fs_context *fc,
struct fs_parameter *param)
{
struct fs_parse_result result;
int opt, rc;
opt = fs_parse(fc, smack_fs_parameters, param, &result);
if (opt < 0)
return opt;
rc = smack_add_opt(opt, param->string, &fc->security);
if (!rc)
param->string = NULL;
return rc;
}
static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
{
char *from = options, *to = options;
bool first = true;
while (1) {
char *next = strchr(from, ',');
int token, len, rc;
char *arg = NULL;
if (next)
len = next - from;
else
len = strlen(from);
token = match_opt_prefix(from, len, &arg);
if (token != Opt_error) {
arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
rc = smack_add_opt(token, arg, mnt_opts);
if (unlikely(rc)) {
kfree(arg);
if (*mnt_opts)
smack_free_mnt_opts(*mnt_opts);
*mnt_opts = NULL;
return rc;
}
} else {
if (!first) { // copy with preceding comma
from--;
len++;
}
if (to != from)
memmove(to, from, len);
to += len;
first = false;
}
if (!from[len])
break;
from += len + 1;
}
*to = '\0';
return 0;
}
/**
* smack_set_mnt_opts - set Smack specific mount options
* @sb: the file system superblock
* @mnt_opts: Smack mount options
* @kern_flags: mount option from kernel space or user space
* @set_kern_flags: where to store converted mount opts
*
* Returns 0 on success, an error code on failure
*
* Allow filesystems with binary mount data to explicitly set Smack mount
* labels.
*/
static int smack_set_mnt_opts(struct super_block *sb,
void *mnt_opts,
unsigned long kern_flags,
unsigned long *set_kern_flags)
{
struct dentry *root = sb->s_root;
struct inode *inode = d_backing_inode(root);
struct superblock_smack *sp = smack_superblock(sb);
struct inode_smack *isp;
struct smack_known *skp;
struct smack_mnt_opts *opts = mnt_opts;
bool transmute = false;
if (sp->smk_flags & SMK_SB_INITIALIZED)
return 0;
if (!smack_privileged(CAP_MAC_ADMIN)) {
/*
* Unprivileged mounts don't get to specify Smack values.
*/
if (opts)
return -EPERM;
/*
* Unprivileged mounts get root and default from the caller.
*/
skp = smk_of_current();
sp->smk_root = skp;
sp->smk_default = skp;
/*
* For a handful of fs types with no user-controlled
* backing store it's okay to trust security labels
* in the filesystem. The rest are untrusted.
*/
if (sb->s_user_ns != &init_user_ns &&
sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
sb->s_magic != RAMFS_MAGIC) {
transmute = true;
sp->smk_flags |= SMK_SB_UNTRUSTED;
}
}
sp->smk_flags |= SMK_SB_INITIALIZED;
if (opts) {
if (opts->fsdefault) {
skp = smk_import_entry(opts->fsdefault, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_default = skp;
}
if (opts->fsfloor) {
skp = smk_import_entry(opts->fsfloor, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_floor = skp;
}
if (opts->fshat) {
skp = smk_import_entry(opts->fshat, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_hat = skp;
}
if (opts->fsroot) {
skp = smk_import_entry(opts->fsroot, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_root = skp;
}
if (opts->fstransmute) {
skp = smk_import_entry(opts->fstransmute, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_root = skp;
transmute = true;
}
}
/*
* Initialize the root inode.
*/
init_inode_smack(inode, sp->smk_root);
if (transmute) {
isp = smack_inode(inode);
isp->smk_flags |= SMK_INODE_TRANSMUTE;
}
return 0;
}
/**
* smack_sb_statfs - Smack check on statfs
* @dentry: identifies the file system in question
*
* Returns 0 if current can read the floor of the filesystem,
* and error code otherwise
*/
static int smack_sb_statfs(struct dentry *dentry)
{
struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
int rc;
struct smk_audit_info ad;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
return rc;
}
/*
* BPRM hooks
*/
/**
* smack_bprm_creds_for_exec - Update bprm->cred if needed for exec
* @bprm: the exec information
*
* Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
*/
static int smack_bprm_creds_for_exec(struct linux_binprm *bprm)
{
struct inode *inode = file_inode(bprm->file);
struct task_smack *bsp = smack_cred(bprm->cred);
struct inode_smack *isp;
struct superblock_smack *sbsp;
int rc;
isp = smack_inode(inode);
if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
return 0;
sbsp = smack_superblock(inode->i_sb);
if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
isp->smk_task != sbsp->smk_root)
return 0;
if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
struct task_struct *tracer;
rc = 0;
rcu_read_lock();
tracer = ptrace_parent(current);
if (likely(tracer != NULL))
rc = smk_ptrace_rule_check(tracer,
isp->smk_task,
PTRACE_MODE_ATTACH,
__func__);
rcu_read_unlock();
if (rc != 0)
return rc;
}
if (bprm->unsafe & ~LSM_UNSAFE_PTRACE)
return -EPERM;
bsp->smk_task = isp->smk_task;
bprm->per_clear |= PER_CLEAR_ON_SETID;
/* Decide if this is a secure exec. */
if (bsp->smk_task != bsp->smk_forked)
bprm->secureexec = 1;
return 0;
}
/*
* Inode hooks
*/
/**
* smack_inode_alloc_security - allocate an inode blob
* @inode: the inode in need of a blob
*
* Returns 0
*/
static int smack_inode_alloc_security(struct inode *inode)
{
struct smack_known *skp = smk_of_current();
init_inode_smack(inode, skp);
return 0;
}
/**
* smack_inode_init_security - copy out the smack from an inode
* @inode: the newly created inode
* @dir: containing directory object
* @qstr: unused
* @name: where to put the attribute name
* @value: where to put the attribute value
* @len: where to put the length of the attribute
*
* Returns 0 if it all works out, -ENOMEM if there's no memory
*/
static int smack_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr, const char **name,
void **value, size_t *len)
{
struct inode_smack *issp = smack_inode(inode);
struct smack_known *skp = smk_of_current();
struct smack_known *isp = smk_of_inode(inode);
struct smack_known *dsp = smk_of_inode(dir);
int may;
if (name)
*name = XATTR_SMACK_SUFFIX;
if (value && len) {
rcu_read_lock();
may = smk_access_entry(skp->smk_known, dsp->smk_known,
&skp->smk_rules);
rcu_read_unlock();
/*
* If the access rule allows transmutation and
* the directory requests transmutation then
* by all means transmute.
* Mark the inode as changed.
*/
if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
smk_inode_transmutable(dir)) {
isp = dsp;
issp->smk_flags |= SMK_INODE_CHANGED;
}
*value = kstrdup(isp->smk_known, GFP_NOFS);
if (*value == NULL)
return -ENOMEM;
*len = strlen(isp->smk_known);
}
return 0;
}
/**
* smack_inode_link - Smack check on link
* @old_dentry: the existing object
* @dir: unused
* @new_dentry: the new object
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry)
{
struct smack_known *isp;
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
isp = smk_of_inode(d_backing_inode(old_dentry));
rc = smk_curacc(isp, MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
if (rc == 0 && d_is_positive(new_dentry)) {
isp = smk_of_inode(d_backing_inode(new_dentry));
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
rc = smk_curacc(isp, MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
}
return rc;
}
/**
* smack_inode_unlink - Smack check on inode deletion
* @dir: containing directory object
* @dentry: file to unlink
*
* Returns 0 if current can write the containing directory
* and the object, error code otherwise
*/
static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
{
struct inode *ip = d_backing_inode(dentry);
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
/*
* You need write access to the thing you're unlinking
*/
rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
rc = smk_bu_inode(ip, MAY_WRITE, rc);
if (rc == 0) {
/*
* You also need write access to the containing directory
*/
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
smk_ad_setfield_u_fs_inode(&ad, dir);
rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
rc = smk_bu_inode(dir, MAY_WRITE, rc);
}
return rc;
}
/**
* smack_inode_rmdir - Smack check on directory deletion
* @dir: containing directory object
* @dentry: directory to unlink
*
* Returns 0 if current can write the containing directory
* and the directory, error code otherwise
*/
static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
{
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
/*
* You need write access to the thing you're removing
*/
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
if (rc == 0) {
/*
* You also need write access to the containing directory
*/
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
smk_ad_setfield_u_fs_inode(&ad, dir);
rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
rc = smk_bu_inode(dir, MAY_WRITE, rc);
}
return rc;
}
/**
* smack_inode_rename - Smack check on rename
* @old_inode: unused
* @old_dentry: the old object
* @new_inode: unused
* @new_dentry: the new object
*
* Read and write access is required on both the old and
* new directories.
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_rename(struct inode *old_inode,
struct dentry *old_dentry,
struct inode *new_inode,
struct dentry *new_dentry)
{
int rc;
struct smack_known *isp;
struct smk_audit_info ad;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
isp = smk_of_inode(d_backing_inode(old_dentry));
rc = smk_curacc(isp, MAY_READWRITE, &ad);
rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
if (rc == 0 && d_is_positive(new_dentry)) {
isp = smk_of_inode(d_backing_inode(new_dentry));
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
rc = smk_curacc(isp, MAY_READWRITE, &ad);
rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
}
return rc;
}
/**
* smack_inode_permission - Smack version of permission()
* @inode: the inode in question
* @mask: the access requested
*
* This is the important Smack hook.
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_permission(struct inode *inode, int mask)
{
struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
struct smk_audit_info ad;
int no_block = mask & MAY_NOT_BLOCK;
int rc;
mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
/*
* No permission to check. Existence test. Yup, it's there.
*/
if (mask == 0)
return 0;
if (sbsp->smk_flags & SMK_SB_UNTRUSTED) {
if (smk_of_inode(inode) != sbsp->smk_root)
return -EACCES;
}
/* May be droppable after audit */
if (no_block)
return -ECHILD;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
smk_ad_setfield_u_fs_inode(&ad, inode);
rc = smk_curacc(smk_of_inode(inode), mask, &ad);
rc = smk_bu_inode(inode, mask, rc);
return rc;
}
/**
* smack_inode_setattr - Smack check for setting attributes
* @dentry: the object
* @iattr: for the force flag
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct smk_audit_info ad;
int rc;
/*
* Need to allow for clearing the setuid bit.
*/
if (iattr->ia_valid & ATTR_FORCE)
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
return rc;
}
/**
* smack_inode_getattr - Smack check for getting attributes
* @path: path to extract the info from
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_getattr(const struct path *path)
{
struct smk_audit_info ad;
struct inode *inode = d_backing_inode(path->dentry);
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, *path);
rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
rc = smk_bu_inode(inode, MAY_READ, rc);
return rc;
}
/**
* smack_inode_setxattr - Smack check for setting xattrs
* @idmap: idmap of the mount
* @dentry: the object
* @name: name of the attribute
* @value: value of the attribute
* @size: size of the value
* @flags: unused
*
* This protects the Smack attribute explicitly.
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_setxattr(struct mnt_idmap *idmap,
struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct smk_audit_info ad;
struct smack_known *skp;
int check_priv = 0;
int check_import = 0;
int check_star = 0;
int rc = 0;
/*
* Check label validity here so import won't fail in post_setxattr
*/
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
check_priv = 1;
check_import = 1;
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
check_priv = 1;
check_import = 1;
check_star = 1;
} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
check_priv = 1;
if (size != TRANS_TRUE_SIZE ||
strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
rc = -EINVAL;
} else
rc = cap_inode_setxattr(dentry, name, value, size, flags);
if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
rc = -EPERM;
if (rc == 0 && check_import) {
skp = size ? smk_import_entry(value, size) : NULL;
if (IS_ERR(skp))
rc = PTR_ERR(skp);
else if (skp == NULL || (check_star &&
(skp == &smack_known_star || skp == &smack_known_web)))
rc = -EINVAL;
}
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
if (rc == 0) {
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
}
return rc;
}
/**
* smack_inode_post_setxattr - Apply the Smack update approved above
* @dentry: object
* @name: attribute name
* @value: attribute value
* @size: attribute size
* @flags: unused
*
* Set the pointer in the inode blob to the entry found
* in the master label list.
*/
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct smack_known *skp;
struct inode_smack *isp = smack_inode(d_backing_inode(dentry));
if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
isp->smk_flags |= SMK_INODE_TRANSMUTE;
return;
}
if (strcmp(name, XATTR_NAME_SMACK) == 0) {
skp = smk_import_entry(value, size);
if (!IS_ERR(skp))
isp->smk_inode = skp;
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
skp = smk_import_entry(value, size);
if (!IS_ERR(skp))
isp->smk_task = skp;
} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
skp = smk_import_entry(value, size);
if (!IS_ERR(skp))
isp->smk_mmap = skp;
}
return;
}
/**
* smack_inode_getxattr - Smack check on getxattr
* @dentry: the object
* @name: unused
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_getxattr(struct dentry *dentry, const char *name)
{
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
return rc;
}
/**
* smack_inode_removexattr - Smack check on removexattr
* @idmap: idmap of the mount
* @dentry: the object
* @name: name of the attribute
*
* Removing the Smack attribute requires CAP_MAC_ADMIN
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_removexattr(struct mnt_idmap *idmap,
struct dentry *dentry, const char *name)
{
struct inode_smack *isp;
struct smk_audit_info ad;
int rc = 0;
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
if (!smack_privileged(CAP_MAC_ADMIN))
rc = -EPERM;
} else
rc = cap_inode_removexattr(idmap, dentry, name);
if (rc != 0)
return rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
if (rc != 0)
return rc;
isp = smack_inode(d_backing_inode(dentry));
/*
* Don't do anything special for these.
* XATTR_NAME_SMACKIPIN
* XATTR_NAME_SMACKIPOUT
*/
if (strcmp(name, XATTR_NAME_SMACK) == 0) {
struct super_block *sbp = dentry->d_sb;
struct superblock_smack *sbsp = smack_superblock(sbp);
isp->smk_inode = sbsp->smk_default;
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
isp->smk_task = NULL;
else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
isp->smk_mmap = NULL;
else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
return 0;
}
/**
* smack_inode_set_acl - Smack check for setting posix acls
* @idmap: idmap of the mnt this request came from
* @dentry: the object
* @acl_name: name of the posix acl
* @kacl: the posix acls
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_set_acl(struct mnt_idmap *idmap,
struct dentry *dentry, const char *acl_name,
struct posix_acl *kacl)
{
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
return rc;
}
/**
* smack_inode_get_acl - Smack check for getting posix acls
* @idmap: idmap of the mnt this request came from
* @dentry: the object
* @acl_name: name of the posix acl
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_get_acl(struct mnt_idmap *idmap,
struct dentry *dentry, const char *acl_name)
{
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
return rc;
}
/**
* smack_inode_remove_acl - Smack check for getting posix acls
* @idmap: idmap of the mnt this request came from
* @dentry: the object
* @acl_name: name of the posix acl
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_remove_acl(struct mnt_idmap *idmap,
struct dentry *dentry, const char *acl_name)
{
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
return rc;
}
/**
* smack_inode_getsecurity - get smack xattrs
* @idmap: idmap of the mount
* @inode: the object
* @name: attribute name
* @buffer: where to put the result
* @alloc: duplicate memory
*
* Returns the size of the attribute or an error code
*/
static int smack_inode_getsecurity(struct mnt_idmap *idmap,
struct inode *inode, const char *name,
void **buffer, bool alloc)
{
struct socket_smack *ssp;
struct socket *sock;
struct super_block *sbp;
struct inode *ip = (struct inode *)inode;
struct smack_known *isp;
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0)
isp = smk_of_inode(inode);
else {
/*
* The rest of the Smack xattrs are only on sockets.
*/
sbp = ip->i_sb;
if (sbp->s_magic != SOCKFS_MAGIC)
return -EOPNOTSUPP;
sock = SOCKET_I(ip);
if (sock == NULL || sock->sk == NULL)
return -EOPNOTSUPP;
ssp = sock->sk->sk_security;
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
isp = ssp->smk_in;
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
isp = ssp->smk_out;
else
return -EOPNOTSUPP;
}
if (alloc) {
*buffer = kstrdup(isp->smk_known, GFP_KERNEL);
if (*buffer == NULL)
return -ENOMEM;
}
return strlen(isp->smk_known);
}
/**
* smack_inode_listsecurity - list the Smack attributes
* @inode: the object
* @buffer: where they go
* @buffer_size: size of buffer
*/
static int smack_inode_listsecurity(struct inode *inode, char *buffer,
size_t buffer_size)
{
int len = sizeof(XATTR_NAME_SMACK);
if (buffer != NULL && len <= buffer_size)
memcpy(buffer, XATTR_NAME_SMACK, len);
return len;
}
/**
* smack_inode_getsecid - Extract inode's security id
* @inode: inode to extract the info from
* @secid: where result will be saved
*/
static void smack_inode_getsecid(struct inode *inode, u32 *secid)
{
struct smack_known *skp = smk_of_inode(inode);
*secid = skp->smk_secid;
}
/*
* File Hooks
*/
/*
* There is no smack_file_permission hook
*
* Should access checks be done on each read or write?
* UNICOS and SELinux say yes.
* Trusted Solaris, Trusted Irix, and just about everyone else says no.
*
* I'll say no for now. Smack does not do the frequent
* label changing that SELinux does.
*/
/**
* smack_file_alloc_security - assign a file security blob
* @file: the object
*
* The security blob for a file is a pointer to the master
* label list, so no allocation is done.
*
* f_security is the owner security information. It
* isn't used on file access checks, it's for send_sigio.
*
* Returns 0
*/
static int smack_file_alloc_security(struct file *file)
{
struct smack_known **blob = smack_file(file);
*blob = smk_of_current();
return 0;
}
/**
* smack_file_ioctl - Smack check on ioctls
* @file: the object
* @cmd: what to do
* @arg: unused
*
* Relies heavily on the correct use of the ioctl command conventions.
*
* Returns 0 if allowed, error code otherwise
*/
static int smack_file_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int rc = 0;
struct smk_audit_info ad;
struct inode *inode = file_inode(file);
if (unlikely(IS_PRIVATE(inode)))
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
if (_IOC_DIR(cmd) & _IOC_WRITE) {
rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
rc = smk_bu_file(file, MAY_WRITE, rc);
}
if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
rc = smk_bu_file(file, MAY_READ, rc);
}
return rc;
}
/**
* smack_file_lock - Smack check on file locking
* @file: the object
* @cmd: unused
*
* Returns 0 if current has lock access, error code otherwise
*/
static int smack_file_lock(struct file *file, unsigned int cmd)
{
struct smk_audit_info ad;
int rc;
struct inode *inode = file_inode(file);
if (unlikely(IS_PRIVATE(inode)))
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
rc = smk_bu_file(file, MAY_LOCK, rc);
return rc;
}
/**
* smack_file_fcntl - Smack check on fcntl
* @file: the object
* @cmd: what action to check
* @arg: unused
*
* Generally these operations are harmless.
* File locking operations present an obvious mechanism
* for passing information, so they require write access.
*
* Returns 0 if current has access, error code otherwise
*/
static int smack_file_fcntl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct smk_audit_info ad;
int rc = 0;
struct inode *inode = file_inode(file);
if (unlikely(IS_PRIVATE(inode)))
return 0;
switch (cmd) {
case F_GETLK:
break;
case F_SETLK:
case F_SETLKW:
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
rc = smk_bu_file(file, MAY_LOCK, rc);
break;
case F_SETOWN:
case F_SETSIG:
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
rc = smk_bu_file(file, MAY_WRITE, rc);
break;
default:
break;
}
return rc;
}
/**
* smack_mmap_file - Check permissions for a mmap operation.
* @file: contains the file structure for file to map (may be NULL).
* @reqprot: contains the protection requested by the application.
* @prot: contains the protection that will be applied by the kernel.
* @flags: contains the operational flags.
*
* The @file may be NULL, e.g. if mapping anonymous memory.
*
* Return 0 if permission is granted.
*/
static int smack_mmap_file(struct file *file,
unsigned long reqprot, unsigned long prot,
unsigned long flags)
{
struct smack_known *skp;
struct smack_known *mkp;
struct smack_rule *srp;
struct task_smack *tsp;
struct smack_known *okp;
struct inode_smack *isp;
struct superblock_smack *sbsp;
int may;
int mmay;
int tmay;
int rc;
if (file == NULL)
return 0;
if (unlikely(IS_PRIVATE(file_inode(file))))
return 0;
isp = smack_inode(file_inode(file));
if (isp->smk_mmap == NULL)
return 0;
sbsp = smack_superblock(file_inode(file)->i_sb);
if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
isp->smk_mmap != sbsp->smk_root)
return -EACCES;
mkp = isp->smk_mmap;
tsp = smack_cred(current_cred());
skp = smk_of_current();
rc = 0;
rcu_read_lock();
/*
* For each Smack rule associated with the subject
* label verify that the SMACK64MMAP also has access
* to that rule's object label.
*/
list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
okp = srp->smk_object;
/*
* Matching labels always allows access.
*/
if (mkp->smk_known == okp->smk_known)
continue;
/*
* If there is a matching local rule take
* that into account as well.
*/
may = smk_access_entry(srp->smk_subject->smk_known,
okp->smk_known,
&tsp->smk_rules);
if (may == -ENOENT)
may = srp->smk_access;
else
may &= srp->smk_access;
/*
* If may is zero the SMACK64MMAP subject can't
* possibly have less access.
*/
if (may == 0)
continue;
/*
* Fetch the global list entry.
* If there isn't one a SMACK64MMAP subject
* can't have as much access as current.
*/
mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
&mkp->smk_rules);
if (mmay == -ENOENT) {
rc = -EACCES;
break;
}
/*
* If there is a local entry it modifies the
* potential access, too.
*/
tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
&tsp->smk_rules);
if (tmay != -ENOENT)
mmay &= tmay;
/*
* If there is any access available to current that is
* not available to a SMACK64MMAP subject
* deny access.
*/
if ((may | mmay) != mmay) {
rc = -EACCES;
break;
}
}
rcu_read_unlock();
return rc;
}
/**
* smack_file_set_fowner - set the file security blob value
* @file: object in question
*
*/
static void smack_file_set_fowner(struct file *file)
{
struct smack_known **blob = smack_file(file);
*blob = smk_of_current();
}
/**
* smack_file_send_sigiotask - Smack on sigio
* @tsk: The target task
* @fown: the object the signal come from
* @signum: unused
*
* Allow a privileged task to get signals even if it shouldn't
*
* Returns 0 if a subject with the object's smack could
* write to the task, an error code otherwise.
*/
static int smack_file_send_sigiotask(struct task_struct *tsk,
struct fown_struct *fown, int signum)
{
struct smack_known **blob;
struct smack_known *skp;
struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred));
const struct cred *tcred;
struct file *file;
int rc;
struct smk_audit_info ad;
/*
* struct fown_struct is never outside the context of a struct file
*/
file = container_of(fown, struct file, f_owner);
/* we don't log here as rc can be overriden */
blob = smack_file(file);
skp = *blob;
rc = smk_access(skp, tkp, MAY_DELIVER, NULL);
rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc);
rcu_read_lock();
tcred = __task_cred(tsk);
if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred))
rc = 0;
rcu_read_unlock();
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, tsk);
smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad);
return rc;
}
/**
* smack_file_receive - Smack file receive check
* @file: the object
*
* Returns 0 if current has access, error code otherwise
*/
static int smack_file_receive(struct file *file)
{
int rc;
int may = 0;
struct smk_audit_info ad;
struct inode *inode = file_inode(file);
struct socket *sock;
struct task_smack *tsp;
struct socket_smack *ssp;
if (unlikely(IS_PRIVATE(inode)))
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
sock = SOCKET_I(inode);
ssp = sock->sk->sk_security;
tsp = smack_cred(current_cred());
/*
* If the receiving process can't write to the
* passed socket or if the passed socket can't
* write to the receiving process don't accept
* the passed socket.
*/
rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad);
rc = smk_bu_file(file, may, rc);
if (rc < 0)
return rc;
rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad);
rc = smk_bu_file(file, may, rc);
return rc;
}
/*
* This code relies on bitmasks.
*/
if (file->f_mode & FMODE_READ)
may = MAY_READ;
if (file->f_mode & FMODE_WRITE)
may |= MAY_WRITE;
rc = smk_curacc(smk_of_inode(inode), may, &ad);
rc = smk_bu_file(file, may, rc);
return rc;
}
/**
* smack_file_open - Smack dentry open processing
* @file: the object
*
* Set the security blob in the file structure.
* Allow the open only if the task has read access. There are
* many read operations (e.g. fstat) that you can do with an
* fd even if you have the file open write-only.
*
* Returns 0 if current has access, error code otherwise
*/
static int smack_file_open(struct file *file)
{
struct task_smack *tsp = smack_cred(file->f_cred);
struct inode *inode = file_inode(file);
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
return rc;
}
/*
* Task hooks
*/
/**
* smack_cred_alloc_blank - "allocate" blank task-level security credentials
* @cred: the new credentials
* @gfp: the atomicity of any memory allocations
*
* Prepare a blank set of credentials for modification. This must allocate all
* the memory the LSM module might require such that cred_transfer() can
* complete without error.
*/
static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
init_task_smack(smack_cred(cred), NULL, NULL);
return 0;
}
/**
* smack_cred_free - "free" task-level security credentials
* @cred: the credentials in question
*
*/
static void smack_cred_free(struct cred *cred)
{
struct task_smack *tsp = smack_cred(cred);
struct smack_rule *rp;
struct list_head *l;
struct list_head *n;
smk_destroy_label_list(&tsp->smk_relabel);
list_for_each_safe(l, n, &tsp->smk_rules) {
rp = list_entry(l, struct smack_rule, list);
list_del(&rp->list);
kmem_cache_free(smack_rule_cache, rp);
}
}
/**
* smack_cred_prepare - prepare new set of credentials for modification
* @new: the new credentials
* @old: the original credentials
* @gfp: the atomicity of any memory allocations
*
* Prepare a new set of credentials for modification.
*/
static int smack_cred_prepare(struct cred *new, const struct cred *old,
gfp_t gfp)
{
struct task_smack *old_tsp = smack_cred(old);
struct task_smack *new_tsp = smack_cred(new);
int rc;
init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
if (rc != 0)
return rc;
rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
gfp);
return rc;
}
/**
* smack_cred_transfer - Transfer the old credentials to the new credentials
* @new: the new credentials
* @old: the original credentials
*
* Fill in a set of blank credentials from another set of credentials.
*/
static void smack_cred_transfer(struct cred *new, const struct cred *old)
{
struct task_smack *old_tsp = smack_cred(old);
struct task_smack *new_tsp = smack_cred(new);
new_tsp->smk_task = old_tsp->smk_task;
new_tsp->smk_forked = old_tsp->smk_task;
mutex_init(&new_tsp->smk_rules_lock);
INIT_LIST_HEAD(&new_tsp->smk_rules);
/* cbs copy rule list */
}
/**
* smack_cred_getsecid - get the secid corresponding to a creds structure
* @cred: the object creds
* @secid: where to put the result
*
* Sets the secid to contain a u32 version of the smack label.
*/
static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
{
struct smack_known *skp;
rcu_read_lock();
skp = smk_of_task(smack_cred(cred));
*secid = skp->smk_secid;
rcu_read_unlock();
}
/**
* smack_kernel_act_as - Set the subjective context in a set of credentials
* @new: points to the set of credentials to be modified.
* @secid: specifies the security ID to be set
*
* Set the security data for a kernel service.
*/
static int smack_kernel_act_as(struct cred *new, u32 secid)
{
struct task_smack *new_tsp = smack_cred(new);
new_tsp->smk_task = smack_from_secid(secid);
return 0;
}
/**
* smack_kernel_create_files_as - Set the file creation label in a set of creds
* @new: points to the set of credentials to be modified
* @inode: points to the inode to use as a reference
*
* Set the file creation context in a set of credentials to the same
* as the objective context of the specified inode
*/
static int smack_kernel_create_files_as(struct cred *new,
struct inode *inode)
{
struct inode_smack *isp = smack_inode(inode);
struct task_smack *tsp = smack_cred(new);
tsp->smk_forked = isp->smk_inode;
tsp->smk_task = tsp->smk_forked;
return 0;
}
/**
* smk_curacc_on_task - helper to log task related access
* @p: the task object
* @access: the access requested
* @caller: name of the calling function for audit
*
* Return 0 if access is permitted
*/
static int smk_curacc_on_task(struct task_struct *p, int access,
const char *caller)
{
struct smk_audit_info ad;
struct smack_known *skp = smk_of_task_struct_obj(p);
int rc;
smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, p);
rc = smk_curacc(skp, access, &ad);
rc = smk_bu_task(p, access, rc);
return rc;
}
/**
* smack_task_setpgid - Smack check on setting pgid
* @p: the task object
* @pgid: unused
*
* Return 0 if write access is permitted
*/
static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_getpgid - Smack access check for getpgid
* @p: the object task
*
* Returns 0 if current can read the object task, error code otherwise
*/
static int smack_task_getpgid(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
* smack_task_getsid - Smack access check for getsid
* @p: the object task
*
* Returns 0 if current can read the object task, error code otherwise
*/
static int smack_task_getsid(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
* smack_current_getsecid_subj - get the subjective secid of the current task
* @secid: where to put the result
*
* Sets the secid to contain a u32 version of the task's subjective smack label.
*/
static void smack_current_getsecid_subj(u32 *secid)
{
struct smack_known *skp = smk_of_current();
*secid = skp->smk_secid;
}
/**
* smack_task_getsecid_obj - get the objective secid of the task
* @p: the task
* @secid: where to put the result
*
* Sets the secid to contain a u32 version of the task's objective smack label.
*/
static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid)
{
struct smack_known *skp = smk_of_task_struct_obj(p);
*secid = skp->smk_secid;
}
/**
* smack_task_setnice - Smack check on setting nice
* @p: the task object
* @nice: unused
*
* Return 0 if write access is permitted
*/
static int smack_task_setnice(struct task_struct *p, int nice)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_setioprio - Smack check on setting ioprio
* @p: the task object
* @ioprio: unused
*
* Return 0 if write access is permitted
*/
static int smack_task_setioprio(struct task_struct *p, int ioprio)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_getioprio - Smack check on reading ioprio
* @p: the task object
*
* Return 0 if read access is permitted
*/
static int smack_task_getioprio(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
* smack_task_setscheduler - Smack check on setting scheduler
* @p: the task object
*
* Return 0 if read access is permitted
*/
static int smack_task_setscheduler(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_getscheduler - Smack check on reading scheduler
* @p: the task object
*
* Return 0 if read access is permitted
*/
static int smack_task_getscheduler(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
* smack_task_movememory - Smack check on moving memory
* @p: the task object
*
* Return 0 if write access is permitted
*/
static int smack_task_movememory(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_kill - Smack check on signal delivery
* @p: the task object
* @info: unused
* @sig: unused
* @cred: identifies the cred to use in lieu of current's
*
* Return 0 if write access is permitted
*
*/
static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
int sig, const struct cred *cred)
{
struct smk_audit_info ad;
struct smack_known *skp;
struct smack_known *tkp = smk_of_task_struct_obj(p);
int rc;
if (!sig)
return 0; /* null signal; existence test */
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, p);
/*
* Sending a signal requires that the sender
* can write the receiver.
*/
if (cred == NULL) {
rc = smk_curacc(tkp, MAY_DELIVER, &ad);
rc = smk_bu_task(p, MAY_DELIVER, rc);
return rc;
}
/*
* If the cred isn't NULL we're dealing with some USB IO
* specific behavior. This is not clean. For one thing
* we can't take privilege into account.
*/
skp = smk_of_task(smack_cred(cred));
rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
return rc;
}
/**
* smack_task_to_inode - copy task smack into the inode blob
* @p: task to copy from
* @inode: inode to copy to
*
* Sets the smack pointer in the inode security blob
*/
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
{
struct inode_smack *isp = smack_inode(inode);
struct smack_known *skp = smk_of_task_struct_obj(p);
isp->smk_inode = skp;
isp->smk_flags |= SMK_INODE_INSTANT;
}
/*
* Socket hooks.
*/
/**
* smack_sk_alloc_security - Allocate a socket blob
* @sk: the socket
* @family: unused
* @gfp_flags: memory allocation flags
*
* Assign Smack pointers to current
*
* Returns 0 on success, -ENOMEM is there's no memory
*/
static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
{
struct smack_known *skp = smk_of_current();
struct socket_smack *ssp;
ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
if (ssp == NULL)
return -ENOMEM;
/*
* Sockets created by kernel threads receive web label.
*/
if (unlikely(current->flags & PF_KTHREAD)) {
ssp->smk_in = &smack_known_web;
ssp->smk_out = &smack_known_web;
} else {
ssp->smk_in = skp;
ssp->smk_out = skp;
}
ssp->smk_packet = NULL;
sk->sk_security = ssp;
return 0;
}
/**
* smack_sk_free_security - Free a socket blob
* @sk: the socket
*
* Clears the blob pointer
*/
static void smack_sk_free_security(struct sock *sk)
{
#ifdef SMACK_IPV6_PORT_LABELING
struct smk_port_label *spp;
if (sk->sk_family == PF_INET6) {
rcu_read_lock();
list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
if (spp->smk_sock != sk)
continue;
spp->smk_can_reuse = 1;
break;
}
rcu_read_unlock();
}
#endif
kfree(sk->sk_security);
}
/**
* smack_sk_clone_security - Copy security context
* @sk: the old socket
* @newsk: the new socket
*
* Copy the security context of the old socket pointer to the cloned
*/
static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk)
{
struct socket_smack *ssp_old = sk->sk_security;
struct socket_smack *ssp_new = newsk->sk_security;
*ssp_new = *ssp_old;
}
/**
* smack_ipv4host_label - check host based restrictions
* @sip: the object end
*
* looks for host based access restrictions
*
* This version will only be appropriate for really small sets of single label
* hosts. The caller is responsible for ensuring that the RCU read lock is
* taken before calling this function.
*
* Returns the label of the far end or NULL if it's not special.
*/
static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
{
struct smk_net4addr *snp;
struct in_addr *siap = &sip->sin_addr;
if (siap->s_addr == 0)
return NULL;
list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
/*
* we break after finding the first match because
* the list is sorted from longest to shortest mask
* so we have found the most specific match
*/
if (snp->smk_host.s_addr ==
(siap->s_addr & snp->smk_mask.s_addr))
return snp->smk_label;
return NULL;
}
/*
* smk_ipv6_localhost - Check for local ipv6 host address
* @sip: the address
*
* Returns boolean true if this is the localhost address
*/
static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
{
__be16 *be16p = (__be16 *)&sip->sin6_addr;
__be32 *be32p = (__be32 *)&sip->sin6_addr;
if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
ntohs(be16p[7]) == 1)
return true;
return false;
}
/**
* smack_ipv6host_label - check host based restrictions
* @sip: the object end
*
* looks for host based access restrictions
*
* This version will only be appropriate for really small sets of single label
* hosts. The caller is responsible for ensuring that the RCU read lock is
* taken before calling this function.
*
* Returns the label of the far end or NULL if it's not special.
*/
static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
{
struct smk_net6addr *snp;
struct in6_addr *sap = &sip->sin6_addr;
int i;
int found = 0;
/*
* It's local. Don't look for a host label.
*/
if (smk_ipv6_localhost(sip))
return NULL;
list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
/*
* If the label is NULL the entry has
* been renounced. Ignore it.
*/
if (snp->smk_label == NULL)
continue;
/*
* we break after finding the first match because
* the list is sorted from longest to shortest mask
* so we have found the most specific match
*/
for (found = 1, i = 0; i < 8; i++) {
if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
snp->smk_host.s6_addr16[i]) {
found = 0;
break;
}
}
if (found)
return snp->smk_label;
}
return NULL;
}
/**
* smack_netlbl_add - Set the secattr on a socket
* @sk: the socket
*
* Attach the outbound smack value (smk_out) to the socket.
*
* Returns 0 on success or an error code
*/
static int smack_netlbl_add(struct sock *sk)
{
struct socket_smack *ssp = sk->sk_security;
struct smack_known *skp = ssp->smk_out;
int rc;
local_bh_disable();
bh_lock_sock_nested(sk);
rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
switch (rc) {
case 0:
ssp->smk_state = SMK_NETLBL_LABELED;
break;
case -EDESTADDRREQ:
ssp->smk_state = SMK_NETLBL_REQSKB;
rc = 0;
break;
}
bh_unlock_sock(sk);
local_bh_enable();
return rc;
}
/**
* smack_netlbl_delete - Remove the secattr from a socket
* @sk: the socket
*
* Remove the outbound smack value from a socket
*/
static void smack_netlbl_delete(struct sock *sk)
{
struct socket_smack *ssp = sk->sk_security;
/*
* Take the label off the socket if one is set.
*/
if (ssp->smk_state != SMK_NETLBL_LABELED)
return;
local_bh_disable();
bh_lock_sock_nested(sk);
netlbl_sock_delattr(sk);
bh_unlock_sock(sk);
local_bh_enable();
ssp->smk_state = SMK_NETLBL_UNLABELED;
}
/**
* smk_ipv4_check - Perform IPv4 host access checks
* @sk: the socket
* @sap: the destination address
*
* Set the correct secattr for the given socket based on the destination
* address and perform any outbound access checks needed.
*
* Returns 0 on success or an error code.
*
*/
static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
{
struct smack_known *skp;
int rc = 0;
struct smack_known *hkp;
struct socket_smack *ssp = sk->sk_security;
struct smk_audit_info ad;
rcu_read_lock();
hkp = smack_ipv4host_label(sap);
if (hkp != NULL) {
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = sap->sin_family;
ad.a.u.net->dport = sap->sin_port;
ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
#endif
skp = ssp->smk_out;
rc = smk_access(skp, hkp, MAY_WRITE, &ad);
rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
/*
* Clear the socket netlabel if it's set.
*/
if (!rc)
smack_netlbl_delete(sk);
}
rcu_read_unlock();
return rc;
}
/**
* smk_ipv6_check - check Smack access
* @subject: subject Smack label
* @object: object Smack label
* @address: address
* @act: the action being taken
*
* Check an IPv6 access
*/
static int smk_ipv6_check(struct smack_known *subject,
struct smack_known *object,
struct sockaddr_in6 *address, int act)
{
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
#endif
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = PF_INET6;
ad.a.u.net->dport = address->sin6_port;
if (act == SMK_RECEIVING)
ad.a.u.net->v6info.saddr = address->sin6_addr;
else
ad.a.u.net->v6info.daddr = address->sin6_addr;
#endif
rc = smk_access(subject, object, MAY_WRITE, &ad);
rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
return rc;
}
#ifdef SMACK_IPV6_PORT_LABELING
/**
* smk_ipv6_port_label - Smack port access table management
* @sock: socket
* @address: address
*
* Create or update the port list entry
*/
static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
{
struct sock *sk = sock->sk;
struct sockaddr_in6 *addr6;
struct socket_smack *ssp = sock->sk->sk_security;
struct smk_port_label *spp;
unsigned short port = 0;
if (address == NULL) {
/*
* This operation is changing the Smack information
* on the bound socket. Take the changes to the port
* as well.
*/
rcu_read_lock();
list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
if (sk != spp->smk_sock)
continue;
spp->smk_in = ssp->smk_in;
spp->smk_out = ssp->smk_out;
rcu_read_unlock();
return;
}
/*
* A NULL address is only used for updating existing
* bound entries. If there isn't one, it's OK.
*/
rcu_read_unlock();
return;
}
addr6 = (struct sockaddr_in6 *)address;
port = ntohs(addr6->sin6_port);
/*
* This is a special case that is safely ignored.
*/
if (port == 0)
return;
/*
* Look for an existing port list entry.
* This is an indication that a port is getting reused.
*/
rcu_read_lock();
list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
if (spp->smk_port != port || spp->smk_sock_type != sock->type)
continue;
if (spp->smk_can_reuse != 1) {
rcu_read_unlock();
return;
}
spp->smk_port = port;
spp->smk_sock = sk;
spp->smk_in = ssp->smk_in;
spp->smk_out = ssp->smk_out;
spp->smk_can_reuse = 0;
rcu_read_unlock();
return;
}
rcu_read_unlock();
/*
* A new port entry is required.
*/
spp = kzalloc(sizeof(*spp), GFP_KERNEL);
if (spp == NULL)
return;
spp->smk_port = port;
spp->smk_sock = sk;
spp->smk_in = ssp->smk_in;
spp->smk_out = ssp->smk_out;
spp->smk_sock_type = sock->type;
spp->smk_can_reuse = 0;
mutex_lock(&smack_ipv6_lock);
list_add_rcu(&spp->list, &smk_ipv6_port_list);
mutex_unlock(&smack_ipv6_lock);
return;
}
/**
* smk_ipv6_port_check - check Smack port access
* @sk: socket
* @address: address
* @act: the action being taken
*
* Create or update the port list entry
*/
static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
int act)
{
struct smk_port_label *spp;
struct socket_smack *ssp = sk->sk_security;
struct smack_known *skp = NULL;
unsigned short port;
struct smack_known *object;
if (act == SMK_RECEIVING) {
skp = smack_ipv6host_label(address);
object = ssp->smk_in;
} else {
skp = ssp->smk_out;
object = smack_ipv6host_label(address);
}
/*
* The other end is a single label host.
*/
if (skp != NULL && object != NULL)
return smk_ipv6_check(skp, object, address, act);
if (skp == NULL)
skp = smack_net_ambient;
if (object == NULL)
object = smack_net_ambient;
/*
* It's remote, so port lookup does no good.
*/
if (!smk_ipv6_localhost(address))
return smk_ipv6_check(skp, object, address, act);
/*
* It's local so the send check has to have passed.
*/
if (act == SMK_RECEIVING)
return 0;
port = ntohs(address->sin6_port);
rcu_read_lock();
list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type)
continue;
object = spp->smk_in;
if (act == SMK_CONNECTING)
ssp->smk_packet = spp->smk_out;
break;
}
rcu_read_unlock();
return smk_ipv6_check(skp, object, address, act);
}
#endif
/**
* smack_inode_setsecurity - set smack xattrs
* @inode: the object
* @name: attribute name
* @value: attribute value
* @size: size of the attribute
* @flags: unused
*
* Sets the named attribute in the appropriate blob
*
* Returns 0 on success, or an error code
*/
static int smack_inode_setsecurity(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
struct smack_known *skp;
struct inode_smack *nsp = smack_inode(inode);
struct socket_smack *ssp;
struct socket *sock;
int rc = 0;
if (value == NULL || size > SMK_LONGLABEL || size == 0)
return -EINVAL;
skp = smk_import_entry(value, size);
if (IS_ERR(skp))
return PTR_ERR(skp);
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
nsp->smk_inode = skp;
nsp->smk_flags |= SMK_INODE_INSTANT;
return 0;
}
/*
* The rest of the Smack xattrs are only on sockets.
*/
if (inode->i_sb->s_magic != SOCKFS_MAGIC)
return -EOPNOTSUPP;
sock = SOCKET_I(inode);
if (sock == NULL || sock->sk == NULL)
return -EOPNOTSUPP;
ssp = sock->sk->sk_security;
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
ssp->smk_in = skp;
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
ssp->smk_out = skp;
if (sock->sk->sk_family == PF_INET) {
rc = smack_netlbl_add(sock->sk);
if (rc != 0)
printk(KERN_WARNING
"Smack: \"%s\" netlbl error %d.\n",
__func__, -rc);
}
} else
return -EOPNOTSUPP;
#ifdef SMACK_IPV6_PORT_LABELING
if (sock->sk->sk_family == PF_INET6)
smk_ipv6_port_label(sock, NULL);
#endif
return 0;
}
/**
* smack_socket_post_create - finish socket setup
* @sock: the socket
* @family: protocol family
* @type: unused
* @protocol: unused
* @kern: unused
*
* Sets the netlabel information on the socket
*
* Returns 0 on success, and error code otherwise
*/
static int smack_socket_post_create(struct socket *sock, int family,
int type, int protocol, int kern)
{
struct socket_smack *ssp;
if (sock->sk == NULL)
return 0;
/*
* Sockets created by kernel threads receive web label.
*/
if (unlikely(current->flags & PF_KTHREAD)) {
ssp = sock->sk->sk_security;
ssp->smk_in = &smack_known_web;
ssp->smk_out = &smack_known_web;
}
if (family != PF_INET)
return 0;
/*
* Set the outbound netlbl.
*/
return smack_netlbl_add(sock->sk);
}
/**
* smack_socket_socketpair - create socket pair
* @socka: one socket
* @sockb: another socket
*
* Cross reference the peer labels for SO_PEERSEC
*
* Returns 0
*/
static int smack_socket_socketpair(struct socket *socka,
struct socket *sockb)
{
struct socket_smack *asp = socka->sk->sk_security;
struct socket_smack *bsp = sockb->sk->sk_security;
asp->smk_packet = bsp->smk_out;
bsp->smk_packet = asp->smk_out;
return 0;
}
#ifdef SMACK_IPV6_PORT_LABELING
/**
* smack_socket_bind - record port binding information.
* @sock: the socket
* @address: the port address
* @addrlen: size of the address
*
* Records the label bound to a port.
*
* Returns 0 on success, and error code otherwise
*/
static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
int addrlen)
{
if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) {
if (addrlen < SIN6_LEN_RFC2133 ||
address->sa_family != AF_INET6)
return -EINVAL;
smk_ipv6_port_label(sock, address);
}
return 0;
}
#endif /* SMACK_IPV6_PORT_LABELING */
/**
* smack_socket_connect - connect access check
* @sock: the socket
* @sap: the other end
* @addrlen: size of sap
*
* Verifies that a connection may be possible
*
* Returns 0 on success, and error code otherwise
*/
static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
int addrlen)
{
int rc = 0;
if (sock->sk == NULL)
return 0;
if (sock->sk->sk_family != PF_INET &&
(!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6))
return 0;
if (addrlen < offsetofend(struct sockaddr, sa_family))
return 0;
if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) {
struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
struct smack_known *rsp = NULL;
if (addrlen < SIN6_LEN_RFC2133)
return 0;
if (__is_defined(SMACK_IPV6_SECMARK_LABELING))
rsp = smack_ipv6host_label(sip);
if (rsp != NULL) {
struct socket_smack *ssp = sock->sk->sk_security;
rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
SMK_CONNECTING);
}
#ifdef SMACK_IPV6_PORT_LABELING
rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
#endif
return rc;
}
if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
return 0;
rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap);
return rc;
}
/**
* smack_flags_to_may - convert S_ to MAY_ values
* @flags: the S_ value
*
* Returns the equivalent MAY_ value
*/
static int smack_flags_to_may(int flags)
{
int may = 0;
if (flags & S_IRUGO)
may |= MAY_READ;
if (flags & S_IWUGO)
may |= MAY_WRITE;
if (flags & S_IXUGO)
may |= MAY_EXEC;
return may;
}
/**
* smack_msg_msg_alloc_security - Set the security blob for msg_msg
* @msg: the object
*
* Returns 0
*/
static int smack_msg_msg_alloc_security(struct msg_msg *msg)
{
struct smack_known **blob = smack_msg_msg(msg);
*blob = smk_of_current();
return 0;
}
/**
* smack_of_ipc - the smack pointer for the ipc
* @isp: the object
*
* Returns a pointer to the smack value
*/
static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp)
{
struct smack_known **blob = smack_ipc(isp);
return *blob;
}
/**
* smack_ipc_alloc_security - Set the security blob for ipc
* @isp: the object
*
* Returns 0
*/
static int smack_ipc_alloc_security(struct kern_ipc_perm *isp)
{
struct smack_known **blob = smack_ipc(isp);
*blob = smk_of_current();
return 0;
}
/**
* smk_curacc_shm : check if current has access on shm
* @isp : the object
* @access : access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smk_curacc_shm(struct kern_ipc_perm *isp, int access)
{
struct smack_known *ssp = smack_of_ipc(isp);
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
ad.a.u.ipc_id = isp->id;
#endif
rc = smk_curacc(ssp, access, &ad);
rc = smk_bu_current("shm", ssp, access, rc);
return rc;
}
/**
* smack_shm_associate - Smack access check for shm
* @isp: the object
* @shmflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg)
{
int may;
may = smack_flags_to_may(shmflg);
return smk_curacc_shm(isp, may);
}
/**
* smack_shm_shmctl - Smack access check for shm
* @isp: the object
* @cmd: what it wants to do
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd)
{
int may;
switch (cmd) {
case IPC_STAT:
case SHM_STAT:
case SHM_STAT_ANY:
may = MAY_READ;
break;
case IPC_SET:
case SHM_LOCK:
case SHM_UNLOCK:
case IPC_RMID:
may = MAY_READWRITE;
break;
case IPC_INFO:
case SHM_INFO:
/*
* System level information.
*/
return 0;
default:
return -EINVAL;
}
return smk_curacc_shm(isp, may);
}
/**
* smack_shm_shmat - Smack access for shmat
* @isp: the object
* @shmaddr: unused
* @shmflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr,
int shmflg)
{
int may;
may = smack_flags_to_may(shmflg);
return smk_curacc_shm(isp, may);
}
/**
* smk_curacc_sem : check if current has access on sem
* @isp : the object
* @access : access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smk_curacc_sem(struct kern_ipc_perm *isp, int access)
{
struct smack_known *ssp = smack_of_ipc(isp);
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
ad.a.u.ipc_id = isp->id;
#endif
rc = smk_curacc(ssp, access, &ad);
rc = smk_bu_current("sem", ssp, access, rc);
return rc;
}
/**
* smack_sem_associate - Smack access check for sem
* @isp: the object
* @semflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg)
{
int may;
may = smack_flags_to_may(semflg);
return smk_curacc_sem(isp, may);
}
/**
* smack_sem_semctl - Smack access check for sem
* @isp: the object
* @cmd: what it wants to do
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd)
{
int may;
switch (cmd) {
case GETPID:
case GETNCNT:
case GETZCNT:
case GETVAL:
case GETALL:
case IPC_STAT:
case SEM_STAT:
case SEM_STAT_ANY:
may = MAY_READ;
break;
case SETVAL:
case SETALL:
case IPC_RMID:
case IPC_SET:
may = MAY_READWRITE;
break;
case IPC_INFO:
case SEM_INFO:
/*
* System level information
*/
return 0;
default:
return -EINVAL;
}
return smk_curacc_sem(isp, may);
}
/**
* smack_sem_semop - Smack checks of semaphore operations
* @isp: the object
* @sops: unused
* @nsops: unused
* @alter: unused
*
* Treated as read and write in all cases.
*
* Returns 0 if access is allowed, error code otherwise
*/
static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops,
unsigned nsops, int alter)
{
return smk_curacc_sem(isp, MAY_READWRITE);
}
/**
* smk_curacc_msq : helper to check if current has access on msq
* @isp : the msq
* @access : access requested
*
* return 0 if current has access, error otherwise
*/
static int smk_curacc_msq(struct kern_ipc_perm *isp, int access)
{
struct smack_known *msp = smack_of_ipc(isp);
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
ad.a.u.ipc_id = isp->id;
#endif
rc = smk_curacc(msp, access, &ad);
rc = smk_bu_current("msq", msp, access, rc);
return rc;
}
/**
* smack_msg_queue_associate - Smack access check for msg_queue
* @isp: the object
* @msqflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg)
{
int may;
may = smack_flags_to_may(msqflg);
return smk_curacc_msq(isp, may);
}
/**
* smack_msg_queue_msgctl - Smack access check for msg_queue
* @isp: the object
* @cmd: what it wants to do
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd)
{
int may;
switch (cmd) {
case IPC_STAT:
case MSG_STAT:
case MSG_STAT_ANY:
may = MAY_READ;
break;
case IPC_SET:
case IPC_RMID:
may = MAY_READWRITE;
break;
case IPC_INFO:
case MSG_INFO:
/*
* System level information
*/
return 0;
default:
return -EINVAL;
}
return smk_curacc_msq(isp, may);
}
/**
* smack_msg_queue_msgsnd - Smack access check for msg_queue
* @isp: the object
* @msg: unused
* @msqflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg,
int msqflg)
{
int may;
may = smack_flags_to_may(msqflg);
return smk_curacc_msq(isp, may);
}
/**
* smack_msg_queue_msgrcv - Smack access check for msg_queue
* @isp: the object
* @msg: unused
* @target: unused
* @type: unused
* @mode: unused
*
* Returns 0 if current has read and write access, error code otherwise
*/
static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp,
struct msg_msg *msg,
struct task_struct *target, long type,
int mode)
{
return smk_curacc_msq(isp, MAY_READWRITE);
}
/**
* smack_ipc_permission - Smack access for ipc_permission()
* @ipp: the object permissions
* @flag: access requested
*
* Returns 0 if current has read and write access, error code otherwise
*/
static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
{
struct smack_known **blob = smack_ipc(ipp);
struct smack_known *iskp = *blob;
int may = smack_flags_to_may(flag);
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
ad.a.u.ipc_id = ipp->id;
#endif
rc = smk_curacc(iskp, may, &ad);
rc = smk_bu_current("svipc", iskp, may, rc);
return rc;
}
/**
* smack_ipc_getsecid - Extract smack security id
* @ipp: the object permissions
* @secid: where result will be saved
*/
static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
{
struct smack_known **blob = smack_ipc(ipp);
struct smack_known *iskp = *blob;
*secid = iskp->smk_secid;
}
/**
* smack_d_instantiate - Make sure the blob is correct on an inode
* @opt_dentry: dentry where inode will be attached
* @inode: the object
*
* Set the inode's security blob if it hasn't been done already.
*/
static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
{
struct super_block *sbp;
struct superblock_smack *sbsp;
struct inode_smack *isp;
struct smack_known *skp;
struct smack_known *ckp = smk_of_current();
struct smack_known *final;
char trattr[TRANS_TRUE_SIZE];
int transflag = 0;
int rc;
struct dentry *dp;
if (inode == NULL)
return;
isp = smack_inode(inode);
/*
* If the inode is already instantiated
* take the quick way out
*/
if (isp->smk_flags & SMK_INODE_INSTANT)
return;
sbp = inode->i_sb;
sbsp = smack_superblock(sbp);
/*
* We're going to use the superblock default label
* if there's no label on the file.
*/
final = sbsp->smk_default;
/*
* If this is the root inode the superblock
* may be in the process of initialization.
* If that is the case use the root value out
* of the superblock.
*/
if (opt_dentry->d_parent == opt_dentry) {
switch (sbp->s_magic) {
case CGROUP_SUPER_MAGIC:
case CGROUP2_SUPER_MAGIC:
/*
* The cgroup filesystem is never mounted,
* so there's no opportunity to set the mount
* options.
*/
sbsp->smk_root = &smack_known_star;
sbsp->smk_default = &smack_known_star;
isp->smk_inode = sbsp->smk_root;
break;
case TMPFS_MAGIC:
/*
* What about shmem/tmpfs anonymous files with dentry
* obtained from d_alloc_pseudo()?
*/
isp->smk_inode = smk_of_current();
break;
case PIPEFS_MAGIC:
isp->smk_inode = smk_of_current();
break;
case SOCKFS_MAGIC:
/*
* Socket access is controlled by the socket
* structures associated with the task involved.
*/
isp->smk_inode = &smack_known_star;
break;
default:
isp->smk_inode = sbsp->smk_root;
break;
}
isp->smk_flags |= SMK_INODE_INSTANT;
return;
}
/*
* This is pretty hackish.
* Casey says that we shouldn't have to do
* file system specific code, but it does help
* with keeping it simple.
*/
switch (sbp->s_magic) {
case SMACK_MAGIC:
case CGROUP_SUPER_MAGIC:
case CGROUP2_SUPER_MAGIC:
/*
* Casey says that it's a little embarrassing
* that the smack file system doesn't do
* extended attributes.
*
* Cgroupfs is special
*/
final = &smack_known_star;
break;
case DEVPTS_SUPER_MAGIC:
/*
* devpts seems content with the label of the task.
* Programs that change smack have to treat the
* pty with respect.
*/
final = ckp;
break;
case PROC_SUPER_MAGIC:
/*
* Casey says procfs appears not to care.
* The superblock default suffices.
*/
break;
case TMPFS_MAGIC:
/*
* Device labels should come from the filesystem,
* but watch out, because they're volitile,
* getting recreated on every reboot.
*/
final = &smack_known_star;
/*
* If a smack value has been set we want to use it,
* but since tmpfs isn't giving us the opportunity
* to set mount options simulate setting the
* superblock default.
*/
fallthrough;
default:
/*
* This isn't an understood special case.
* Get the value from the xattr.
*/
/*
* UNIX domain sockets use lower level socket data.
*/
if (S_ISSOCK(inode->i_mode)) {
final = &smack_known_star;
break;
}
/*
* No xattr support means, alas, no SMACK label.
* Use the aforeapplied default.
* It would be curious if the label of the task
* does not match that assigned.
*/
if (!(inode->i_opflags & IOP_XATTR))
break;
/*
* Get the dentry for xattr.
*/
dp = dget(opt_dentry);
skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
if (!IS_ERR_OR_NULL(skp))
final = skp;
/*
* Transmuting directory
*/
if (S_ISDIR(inode->i_mode)) {
/*
* If this is a new directory and the label was
* transmuted when the inode was initialized
* set the transmute attribute on the directory
* and mark the inode.
*
* If there is a transmute attribute on the
* directory mark the inode.
*/
if (isp->smk_flags & SMK_INODE_CHANGED) {
isp->smk_flags &= ~SMK_INODE_CHANGED;
rc = __vfs_setxattr(&nop_mnt_idmap, dp, inode,
XATTR_NAME_SMACKTRANSMUTE,
TRANS_TRUE, TRANS_TRUE_SIZE,
0);
} else {
rc = __vfs_getxattr(dp, inode,
XATTR_NAME_SMACKTRANSMUTE, trattr,
TRANS_TRUE_SIZE);
if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
TRANS_TRUE_SIZE) != 0)
rc = -EINVAL;
}
if (rc >= 0)
transflag = SMK_INODE_TRANSMUTE;
}
/*
* Don't let the exec or mmap label be "*" or "@".
*/
skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
if (IS_ERR(skp) || skp == &smack_known_star ||
skp == &smack_known_web)
skp = NULL;
isp->smk_task = skp;
skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
if (IS_ERR(skp) || skp == &smack_known_star ||
skp == &smack_known_web)
skp = NULL;
isp->smk_mmap = skp;
dput(dp);
break;
}
if (final == NULL)
isp->smk_inode = ckp;
else
isp->smk_inode = final;
isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
return;
}
/**
* smack_getprocattr - Smack process attribute access
* @p: the object task
* @name: the name of the attribute in /proc/.../attr
* @value: where to put the result
*
* Places a copy of the task Smack into value
*
* Returns the length of the smack label or an error code
*/
static int smack_getprocattr(struct task_struct *p, const char *name, char **value)
{
struct smack_known *skp = smk_of_task_struct_obj(p);
char *cp;
int slen;
if (strcmp(name, "current") != 0)
return -EINVAL;
cp = kstrdup(skp->smk_known, GFP_KERNEL);
if (cp == NULL)
return -ENOMEM;
slen = strlen(cp);
*value = cp;
return slen;
}
/**
* smack_setprocattr - Smack process attribute setting
* @name: the name of the attribute in /proc/.../attr
* @value: the value to set
* @size: the size of the value
*
* Sets the Smack value of the task. Only setting self
* is permitted and only with privilege
*
* Returns the length of the smack label or an error code
*/
static int smack_setprocattr(const char *name, void *value, size_t size)
{
struct task_smack *tsp = smack_cred(current_cred());
struct cred *new;
struct smack_known *skp;
struct smack_known_list_elem *sklep;
int rc;
if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
return -EPERM;
if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
return -EINVAL;
if (strcmp(name, "current") != 0)
return -EINVAL;
skp = smk_import_entry(value, size);
if (IS_ERR(skp))
return PTR_ERR(skp);
/*
* No process is ever allowed the web ("@") label
* and the star ("*") label.
*/
if (skp == &smack_known_web || skp == &smack_known_star)
return -EINVAL;
if (!smack_privileged(CAP_MAC_ADMIN)) {
rc = -EPERM;
list_for_each_entry(sklep, &tsp->smk_relabel, list)
if (sklep->smk_label == skp) {
rc = 0;
break;
}
if (rc)
return rc;
}
new = prepare_creds();
if (new == NULL)
return -ENOMEM;
tsp = smack_cred(new);
tsp->smk_task = skp;
/*
* process can change its label only once
*/
smk_destroy_label_list(&tsp->smk_relabel);
commit_creds(new);
return size;
}
/**
* smack_unix_stream_connect - Smack access on UDS
* @sock: one sock
* @other: the other sock
* @newsk: unused
*
* Return 0 if a subject with the smack of sock could access
* an object with the smack of other, otherwise an error code
*/
static int smack_unix_stream_connect(struct sock *sock,
struct sock *other, struct sock *newsk)
{
struct smack_known *skp;
struct smack_known *okp;
struct socket_smack *ssp = sock->sk_security;
struct socket_smack *osp = other->sk_security;
struct socket_smack *nsp = newsk->sk_security;
struct smk_audit_info ad;
int rc = 0;
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
#endif
if (!smack_privileged(CAP_MAC_OVERRIDE)) {
skp = ssp->smk_out;
okp = osp->smk_in;
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
smk_ad_setfield_u_net_sk(&ad, other);
#endif
rc = smk_access(skp, okp, MAY_WRITE, &ad);
rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
if (rc == 0) {
okp = osp->smk_out;
skp = ssp->smk_in;
rc = smk_access(okp, skp, MAY_WRITE, &ad);
rc = smk_bu_note("UDS connect", okp, skp,
MAY_WRITE, rc);
}
}
/*
* Cross reference the peer labels for SO_PEERSEC.
*/
if (rc == 0) {
nsp->smk_packet = ssp->smk_out;
ssp->smk_packet = osp->smk_out;
}
return rc;
}
/**
* smack_unix_may_send - Smack access on UDS
* @sock: one socket
* @other: the other socket
*
* Return 0 if a subject with the smack of sock could access
* an object with the smack of other, otherwise an error code
*/
static int smack_unix_may_send(struct socket *sock, struct socket *other)
{
struct socket_smack *ssp = sock->sk->sk_security;
struct socket_smack *osp = other->sk->sk_security;
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
smk_ad_setfield_u_net_sk(&ad, other->sk);
#endif
if (smack_privileged(CAP_MAC_OVERRIDE))
return 0;
rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
return rc;
}
/**
* smack_socket_sendmsg - Smack check based on destination host
* @sock: the socket
* @msg: the message
* @size: the size of the message
*
* Return 0 if the current subject can write to the destination host.
* For IPv4 this is only a question if the destination is a single label host.
* For IPv6 this is a check against the label of the port.
*/
static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
int size)
{
struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
#if IS_ENABLED(CONFIG_IPV6)
struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
#endif
#ifdef SMACK_IPV6_SECMARK_LABELING
struct socket_smack *ssp = sock->sk->sk_security;
struct smack_known *rsp;
#endif
int rc = 0;
/*
* Perfectly reasonable for this to be NULL
*/
if (sip == NULL)
return 0;
switch (sock->sk->sk_family) {
case AF_INET:
if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
sip->sin_family != AF_INET)
return -EINVAL;
rc = smk_ipv4_check(sock->sk, sip);
break;
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6:
if (msg->msg_namelen < SIN6_LEN_RFC2133 ||
sap->sin6_family != AF_INET6)
return -EINVAL;
#ifdef SMACK_IPV6_SECMARK_LABELING
rsp = smack_ipv6host_label(sap);
if (rsp != NULL)
rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
SMK_CONNECTING);
#endif
#ifdef SMACK_IPV6_PORT_LABELING
rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
#endif
#endif /* IS_ENABLED(CONFIG_IPV6) */
break;
}
return rc;
}
/**
* smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
* @sap: netlabel secattr
* @ssp: socket security information
*
* Returns a pointer to a Smack label entry found on the label list.
*/
static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
struct socket_smack *ssp)
{
struct smack_known *skp;
int found = 0;
int acat;
int kcat;
/*
* Netlabel found it in the cache.
*/
if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
return (struct smack_known *)sap->cache->data;
if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
/*
* Looks like a fallback, which gives us a secid.
*/
return smack_from_secid(sap->attr.secid);
if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
/*
* Looks like a CIPSO packet.
* If there are flags but no level netlabel isn't
* behaving the way we expect it to.
*
* Look it up in the label table
* Without guidance regarding the smack value
* for the packet fall back on the network
* ambient value.
*/
rcu_read_lock();
list_for_each_entry_rcu(skp, &smack_known_list, list) {
if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
continue;
/*
* Compare the catsets. Use the netlbl APIs.
*/
if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
if ((skp->smk_netlabel.flags &
NETLBL_SECATTR_MLS_CAT) == 0)
found = 1;
break;
}
for (acat = -1, kcat = -1; acat == kcat; ) {
acat = netlbl_catmap_walk(sap->attr.mls.cat,
acat + 1);
kcat = netlbl_catmap_walk(
skp->smk_netlabel.attr.mls.cat,
kcat + 1);
if (acat < 0 || kcat < 0)
break;
}
if (acat == kcat) {
found = 1;
break;
}
}
rcu_read_unlock();
if (found)
return skp;
if (ssp != NULL && ssp->smk_in == &smack_known_star)
return &smack_known_web;
return &smack_known_star;
}
/*
* Without guidance regarding the smack value
* for the packet fall back on the network
* ambient value.
*/
return smack_net_ambient;
}
#if IS_ENABLED(CONFIG_IPV6)
static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
{
u8 nexthdr;
int offset;
int proto = -EINVAL;
struct ipv6hdr _ipv6h;
struct ipv6hdr *ip6;
__be16 frag_off;
struct tcphdr _tcph, *th;
struct udphdr _udph, *uh;
struct dccp_hdr _dccph, *dh;
sip->sin6_port = 0;
offset = skb_network_offset(skb);
ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
if (ip6 == NULL)
return -EINVAL;
sip->sin6_addr = ip6->saddr;
nexthdr = ip6->nexthdr;
offset += sizeof(_ipv6h);
offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
if (offset < 0)
return -EINVAL;
proto = nexthdr;
switch (proto) {
case IPPROTO_TCP:
th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
if (th != NULL)
sip->sin6_port = th->source;
break;
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
if (uh != NULL)
sip->sin6_port = uh->source;
break;
case IPPROTO_DCCP:
dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
if (dh != NULL)
sip->sin6_port = dh->dccph_sport;
break;
}
return proto;
}
#endif /* CONFIG_IPV6 */
/**
* smack_from_skb - Smack data from the secmark in an skb
* @skb: packet
*
* Returns smack_known of the secmark or NULL if that won't work.
*/
#ifdef CONFIG_NETWORK_SECMARK
static struct smack_known *smack_from_skb(struct sk_buff *skb)
{
if (skb == NULL || skb->secmark == 0)
return NULL;
return smack_from_secid(skb->secmark);
}
#else
static inline struct smack_known *smack_from_skb(struct sk_buff *skb)
{
return NULL;
}
#endif
/**
* smack_from_netlbl - Smack data from the IP options in an skb
* @sk: socket data came in on
* @family: address family
* @skb: packet
*
* Find the Smack label in the IP options. If it hasn't been
* added to the netlabel cache, add it here.
*
* Returns smack_known of the IP options or NULL if that won't work.
*/
static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
struct sk_buff *skb)
{
struct netlbl_lsm_secattr secattr;
struct socket_smack *ssp = NULL;
struct smack_known *skp = NULL;
netlbl_secattr_init(&secattr);
if (sk)
ssp = sk->sk_security;
if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
skp = smack_from_secattr(&secattr, ssp);
if (secattr.flags & NETLBL_SECATTR_CACHEABLE)
netlbl_cache_add(skb, family, &skp->smk_netlabel);
}
netlbl_secattr_destroy(&secattr);
return skp;
}
/**
* smack_socket_sock_rcv_skb - Smack packet delivery access check
* @sk: socket
* @skb: packet
*
* Returns 0 if the packet should be delivered, an error code otherwise
*/
static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
struct socket_smack *ssp = sk->sk_security;
struct smack_known *skp = NULL;
int rc = 0;
struct smk_audit_info ad;
u16 family = sk->sk_family;
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
#endif
#if IS_ENABLED(CONFIG_IPV6)
struct sockaddr_in6 sadd;
int proto;
if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
family = PF_INET;
#endif /* CONFIG_IPV6 */
switch (family) {
case PF_INET:
/*
* If there is a secmark use it rather than the CIPSO label.
* If there is no secmark fall back to CIPSO.
* The secmark is assumed to reflect policy better.
*/
skp = smack_from_skb(skb);
if (skp == NULL) {
skp = smack_from_netlbl(sk, family, skb);
if (skp == NULL)
skp = smack_net_ambient;
}
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = family;
ad.a.u.net->netif = skb->skb_iif;
ipv4_skb_to_auditdata(skb, &ad.a, NULL);
#endif
/*
* Receiving a packet requires that the other end
* be able to write here. Read access is not required.
* This is the simplist possible security model
* for networking.
*/
rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
MAY_WRITE, rc);
if (rc != 0)
netlbl_skbuff_err(skb, family, rc, 0);
break;
#if IS_ENABLED(CONFIG_IPV6)
case PF_INET6:
proto = smk_skb_to_addr_ipv6(skb, &sadd);
if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE &&
proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
break;
#ifdef SMACK_IPV6_SECMARK_LABELING
skp = smack_from_skb(skb);
if (skp == NULL) {
if (smk_ipv6_localhost(&sadd))
break;
skp = smack_ipv6host_label(&sadd);
if (skp == NULL)
skp = smack_net_ambient;
}
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = family;
ad.a.u.net->netif = skb->skb_iif;
ipv6_skb_to_auditdata(skb, &ad.a, NULL);
#endif /* CONFIG_AUDIT */
rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
MAY_WRITE, rc);
#endif /* SMACK_IPV6_SECMARK_LABELING */
#ifdef SMACK_IPV6_PORT_LABELING
rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
#endif /* SMACK_IPV6_PORT_LABELING */
if (rc != 0)
icmpv6_send(skb, ICMPV6_DEST_UNREACH,
ICMPV6_ADM_PROHIBITED, 0);
break;
#endif /* CONFIG_IPV6 */
}
return rc;
}
/**
* smack_socket_getpeersec_stream - pull in packet label
* @sock: the socket
* @optval: user's destination
* @optlen: size thereof
* @len: max thereof
*
* returns zero on success, an error code otherwise
*/
static int smack_socket_getpeersec_stream(struct socket *sock,
sockptr_t optval, sockptr_t optlen,
unsigned int len)
{
struct socket_smack *ssp;
char *rcp = "";
u32 slen = 1;
int rc = 0;
ssp = sock->sk->sk_security;
if (ssp->smk_packet != NULL) {
rcp = ssp->smk_packet->smk_known;
slen = strlen(rcp) + 1;
}
if (slen > len) {
rc = -ERANGE;
goto out_len;
}
if (copy_to_sockptr(optval, rcp, slen))
rc = -EFAULT;
out_len:
if (copy_to_sockptr(optlen, &slen, sizeof(slen)))
rc = -EFAULT;
return rc;
}
/**
* smack_socket_getpeersec_dgram - pull in packet label
* @sock: the peer socket
* @skb: packet data
* @secid: pointer to where to put the secid of the packet
*
* Sets the netlabel socket state on sk from parent
*/
static int smack_socket_getpeersec_dgram(struct socket *sock,
struct sk_buff *skb, u32 *secid)
{
struct socket_smack *ssp = NULL;
struct smack_known *skp;
struct sock *sk = NULL;
int family = PF_UNSPEC;
u32 s = 0; /* 0 is the invalid secid */
if (skb != NULL) {
if (skb->protocol == htons(ETH_P_IP))
family = PF_INET;
#if IS_ENABLED(CONFIG_IPV6)
else if (skb->protocol == htons(ETH_P_IPV6))
family = PF_INET6;
#endif /* CONFIG_IPV6 */
}
if (family == PF_UNSPEC && sock != NULL)
family = sock->sk->sk_family;
switch (family) {
case PF_UNIX:
ssp = sock->sk->sk_security;
s = ssp->smk_out->smk_secid;
break;
case PF_INET:
skp = smack_from_skb(skb);
if (skp) {
s = skp->smk_secid;
break;
}
/*
* Translate what netlabel gave us.
*/
if (sock != NULL)
sk = sock->sk;
skp = smack_from_netlbl(sk, family, skb);
if (skp != NULL)
s = skp->smk_secid;
break;
case PF_INET6:
#ifdef SMACK_IPV6_SECMARK_LABELING
skp = smack_from_skb(skb);
if (skp)
s = skp->smk_secid;
#endif
break;
}
*secid = s;
if (s == 0)
return -EINVAL;
return 0;
}
/**
* smack_sock_graft - Initialize a newly created socket with an existing sock
* @sk: child sock
* @parent: parent socket
*
* Set the smk_{in,out} state of an existing sock based on the process that
* is creating the new socket.
*/
static void smack_sock_graft(struct sock *sk, struct socket *parent)
{
struct socket_smack *ssp;
struct smack_known *skp = smk_of_current();
if (sk == NULL ||
(sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
return;
ssp = sk->sk_security;
ssp->smk_in = skp;
ssp->smk_out = skp;
/* cssp->smk_packet is already set in smack_inet_csk_clone() */
}
/**
* smack_inet_conn_request - Smack access check on connect
* @sk: socket involved
* @skb: packet
* @req: unused
*
* Returns 0 if a task with the packet label could write to
* the socket, otherwise an error code
*/
static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
u16 family = sk->sk_family;
struct smack_known *skp;
struct socket_smack *ssp = sk->sk_security;
struct sockaddr_in addr;
struct iphdr *hdr;
struct smack_known *hskp;
int rc;
struct smk_audit_info ad;
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
#endif
#if IS_ENABLED(CONFIG_IPV6)
if (family == PF_INET6) {
/*
* Handle mapped IPv4 packets arriving
* via IPv6 sockets. Don't set up netlabel
* processing on IPv6.
*/
if (skb->protocol == htons(ETH_P_IP))
family = PF_INET;
else
return 0;
}
#endif /* CONFIG_IPV6 */
/*
* If there is a secmark use it rather than the CIPSO label.
* If there is no secmark fall back to CIPSO.
* The secmark is assumed to reflect policy better.
*/
skp = smack_from_skb(skb);
if (skp == NULL) {
skp = smack_from_netlbl(sk, family, skb);
if (skp == NULL)
skp = &smack_known_huh;
}
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = family;
ad.a.u.net->netif = skb->skb_iif;
ipv4_skb_to_auditdata(skb, &ad.a, NULL);
#endif
/*
* Receiving a packet requires that the other end be able to write
* here. Read access is not required.
*/
rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
if (rc != 0)
return rc;
/*
* Save the peer's label in the request_sock so we can later setup
* smk_packet in the child socket so that SO_PEERCRED can report it.
*/
req->peer_secid = skp->smk_secid;
/*
* We need to decide if we want to label the incoming connection here
* if we do we only need to label the request_sock and the stack will
* propagate the wire-label to the sock when it is created.
*/
hdr = ip_hdr(skb);
addr.sin_addr.s_addr = hdr->saddr;
rcu_read_lock();
hskp = smack_ipv4host_label(&addr);
rcu_read_unlock();
if (hskp == NULL)
rc = netlbl_req_setattr(req, &skp->smk_netlabel);
else
netlbl_req_delattr(req);
return rc;
}
/**
* smack_inet_csk_clone - Copy the connection information to the new socket
* @sk: the new socket
* @req: the connection's request_sock
*
* Transfer the connection's peer label to the newly created socket.
*/
static void smack_inet_csk_clone(struct sock *sk,
const struct request_sock *req)
{
struct socket_smack *ssp = sk->sk_security;
struct smack_known *skp;
if (req->peer_secid != 0) {
skp = smack_from_secid(req->peer_secid);
ssp->smk_packet = skp;
} else
ssp->smk_packet = NULL;
}
/*
* Key management security hooks
*
* Casey has not tested key support very heavily.
* The permission check is most likely too restrictive.
* If you care about keys please have a look.
*/
#ifdef CONFIG_KEYS
/**
* smack_key_alloc - Set the key security blob
* @key: object
* @cred: the credentials to use
* @flags: unused
*
* No allocation required
*
* Returns 0
*/
static int smack_key_alloc(struct key *key, const struct cred *cred,
unsigned long flags)
{
struct smack_known *skp = smk_of_task(smack_cred(cred));
key->security = skp;
return 0;
}
/**
* smack_key_free - Clear the key security blob
* @key: the object
*
* Clear the blob pointer
*/
static void smack_key_free(struct key *key)
{
key->security = NULL;
}
/**
* smack_key_permission - Smack access on a key
* @key_ref: gets to the object
* @cred: the credentials to use
* @need_perm: requested key permission
*
* Return 0 if the task has read and write to the object,
* an error code otherwise
*/
static int smack_key_permission(key_ref_t key_ref,
const struct cred *cred,
enum key_need_perm need_perm)
{
struct key *keyp;
struct smk_audit_info ad;
struct smack_known *tkp = smk_of_task(smack_cred(cred));
int request = 0;
int rc;
/*
* Validate requested permissions
*/
switch (need_perm) {
case KEY_NEED_READ:
case KEY_NEED_SEARCH:
case KEY_NEED_VIEW:
request |= MAY_READ;
break;
case KEY_NEED_WRITE:
case KEY_NEED_LINK:
case KEY_NEED_SETATTR:
request |= MAY_WRITE;
break;
case KEY_NEED_UNSPECIFIED:
case KEY_NEED_UNLINK:
case KEY_SYSADMIN_OVERRIDE:
case KEY_AUTHTOKEN_OVERRIDE:
case KEY_DEFER_PERM_CHECK:
return 0;
default:
return -EINVAL;
}
keyp = key_ref_to_ptr(key_ref);
if (keyp == NULL)
return -EINVAL;
/*
* If the key hasn't been initialized give it access so that
* it may do so.
*/
if (keyp->security == NULL)
return 0;
/*
* This should not occur
*/
if (tkp == NULL)
return -EACCES;
if (smack_privileged(CAP_MAC_OVERRIDE))
return 0;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
ad.a.u.key_struct.key = keyp->serial;
ad.a.u.key_struct.key_desc = keyp->description;
#endif
rc = smk_access(tkp, keyp->security, request, &ad);
rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
return rc;
}
/*
* smack_key_getsecurity - Smack label tagging the key
* @key points to the key to be queried
* @_buffer points to a pointer that should be set to point to the
* resulting string (if no label or an error occurs).
* Return the length of the string (including terminating NUL) or -ve if
* an error.
* May also return 0 (and a NULL buffer pointer) if there is no label.
*/
static int smack_key_getsecurity(struct key *key, char **_buffer)
{
struct smack_known *skp = key->security;
size_t length;
char *copy;
if (key->security == NULL) {
*_buffer = NULL;
return 0;
}
copy = kstrdup(skp->smk_known, GFP_KERNEL);
if (copy == NULL)
return -ENOMEM;
length = strlen(copy) + 1;
*_buffer = copy;
return length;
}
#ifdef CONFIG_KEY_NOTIFICATIONS
/**
* smack_watch_key - Smack access to watch a key for notifications.
* @key: The key to be watched
*
* Return 0 if the @watch->cred has permission to read from the key object and
* an error otherwise.
*/
static int smack_watch_key(struct key *key)
{
struct smk_audit_info ad;
struct smack_known *tkp = smk_of_current();
int rc;
if (key == NULL)
return -EINVAL;
/*
* If the key hasn't been initialized give it access so that
* it may do so.
*/
if (key->security == NULL)
return 0;
/*
* This should not occur
*/
if (tkp == NULL)
return -EACCES;
if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
return 0;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
ad.a.u.key_struct.key = key->serial;
ad.a.u.key_struct.key_desc = key->description;
#endif
rc = smk_access(tkp, key->security, MAY_READ, &ad);
rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc);
return rc;
}
#endif /* CONFIG_KEY_NOTIFICATIONS */
#endif /* CONFIG_KEYS */
#ifdef CONFIG_WATCH_QUEUE
/**
* smack_post_notification - Smack access to post a notification to a queue
* @w_cred: The credentials of the watcher.
* @cred: The credentials of the event source (may be NULL).
* @n: The notification message to be posted.
*/
static int smack_post_notification(const struct cred *w_cred,
const struct cred *cred,
struct watch_notification *n)
{
struct smk_audit_info ad;
struct smack_known *subj, *obj;
int rc;
/* Always let maintenance notifications through. */
if (n->type == WATCH_TYPE_META)
return 0;
if (!cred)
return 0;
subj = smk_of_task(smack_cred(cred));
obj = smk_of_task(smack_cred(w_cred));
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION);
rc = smk_access(subj, obj, MAY_WRITE, &ad);
rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc);
return rc;
}
#endif /* CONFIG_WATCH_QUEUE */
/*
* Smack Audit hooks
*
* Audit requires a unique representation of each Smack specific
* rule. This unique representation is used to distinguish the
* object to be audited from remaining kernel objects and also
* works as a glue between the audit hooks.
*
* Since repository entries are added but never deleted, we'll use
* the smack_known label address related to the given audit rule as
* the needed unique representation. This also better fits the smack
* model where nearly everything is a label.
*/
#ifdef CONFIG_AUDIT
/**
* smack_audit_rule_init - Initialize a smack audit rule
* @field: audit rule fields given from user-space (audit.h)
* @op: required testing operator (=, !=, >, <, ...)
* @rulestr: smack label to be audited
* @vrule: pointer to save our own audit rule representation
*
* Prepare to audit cases where (@field @op @rulestr) is true.
* The label to be audited is created if necessay.
*/
static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
{
struct smack_known *skp;
char **rule = (char **)vrule;
*rule = NULL;
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
return -EINVAL;
if (op != Audit_equal && op != Audit_not_equal)
return -EINVAL;
skp = smk_import_entry(rulestr, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
*rule = skp->smk_known;
return 0;
}
/**
* smack_audit_rule_known - Distinguish Smack audit rules
* @krule: rule of interest, in Audit kernel representation format
*
* This is used to filter Smack rules from remaining Audit ones.
* If it's proved that this rule belongs to us, the
* audit_rule_match hook will be called to do the final judgement.
*/
static int smack_audit_rule_known(struct audit_krule *krule)
{
struct audit_field *f;
int i;
for (i = 0; i < krule->field_count; i++) {
f = &krule->fields[i];
if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
return 1;
}
return 0;
}
/**
* smack_audit_rule_match - Audit given object ?
* @secid: security id for identifying the object to test
* @field: audit rule flags given from user-space
* @op: required testing operator
* @vrule: smack internal rule presentation
*
* The core Audit hook. It's used to take the decision of
* whether to audit or not to audit a given object.
*/
static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
{
struct smack_known *skp;
char *rule = vrule;
if (unlikely(!rule)) {
WARN_ONCE(1, "Smack: missing rule\n");
return -ENOENT;
}
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
return 0;
skp = smack_from_secid(secid);
/*
* No need to do string comparisons. If a match occurs,
* both pointers will point to the same smack_known
* label.
*/
if (op == Audit_equal)
return (rule == skp->smk_known);
if (op == Audit_not_equal)
return (rule != skp->smk_known);
return 0;
}
/*
* There is no need for a smack_audit_rule_free hook.
* No memory was allocated.
*/
#endif /* CONFIG_AUDIT */
/**
* smack_ismaclabel - check if xattr @name references a smack MAC label
* @name: Full xattr name to check.
*/
static int smack_ismaclabel(const char *name)
{
return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
}
/**
* smack_secid_to_secctx - return the smack label for a secid
* @secid: incoming integer
* @secdata: destination
* @seclen: how long it is
*
* Exists for networking code.
*/
static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
struct smack_known *skp = smack_from_secid(secid);
if (secdata)
*secdata = skp->smk_known;
*seclen = strlen(skp->smk_known);
return 0;
}
/**
* smack_secctx_to_secid - return the secid for a smack label
* @secdata: smack label
* @seclen: how long result is
* @secid: outgoing integer
*
* Exists for audit and networking code.
*/
static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
{
struct smack_known *skp = smk_find_entry(secdata);
if (skp)
*secid = skp->smk_secid;
else
*secid = 0;
return 0;
}
/*
* There used to be a smack_release_secctx hook
* that did nothing back when hooks were in a vector.
* Now that there's a list such a hook adds cost.
*/
static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
{
return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx,
ctxlen, 0);
}
static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
{
return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SMACK,
ctx, ctxlen, 0);
}
static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
{
struct smack_known *skp = smk_of_inode(inode);
*ctx = skp->smk_known;
*ctxlen = strlen(skp->smk_known);
return 0;
}
static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
{
struct task_smack *tsp;
struct smack_known *skp;
struct inode_smack *isp;
struct cred *new_creds = *new;
if (new_creds == NULL) {
new_creds = prepare_creds();
if (new_creds == NULL)
return -ENOMEM;
}
tsp = smack_cred(new_creds);
/*
* Get label from overlay inode and set it in create_sid
*/
isp = smack_inode(d_inode(dentry));
skp = isp->smk_inode;
tsp->smk_task = skp;
*new = new_creds;
return 0;
}
static int smack_inode_copy_up_xattr(const char *name)
{
/*
* Return 1 if this is the smack access Smack attribute.
*/
if (strcmp(name, XATTR_NAME_SMACK) == 0)
return 1;
return -EOPNOTSUPP;
}
static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
struct qstr *name,
const struct cred *old,
struct cred *new)
{
struct task_smack *otsp = smack_cred(old);
struct task_smack *ntsp = smack_cred(new);
struct inode_smack *isp;
int may;
/*
* Use the process credential unless all of
* the transmuting criteria are met
*/
ntsp->smk_task = otsp->smk_task;
/*
* the attribute of the containing directory
*/
isp = smack_inode(d_inode(dentry->d_parent));
if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
rcu_read_lock();
may = smk_access_entry(otsp->smk_task->smk_known,
isp->smk_inode->smk_known,
&otsp->smk_task->smk_rules);
rcu_read_unlock();
/*
* If the directory is transmuting and the rule
* providing access is transmuting use the containing
* directory label instead of the process label.
*/
if (may > 0 && (may & MAY_TRANSMUTE))
ntsp->smk_task = isp->smk_inode;
}
return 0;
}
#ifdef CONFIG_IO_URING
/**
* smack_uring_override_creds - Is io_uring cred override allowed?
* @new: the target creds
*
* Check to see if the current task is allowed to override it's credentials
* to service an io_uring operation.
*/
static int smack_uring_override_creds(const struct cred *new)
{
struct task_smack *tsp = smack_cred(current_cred());
struct task_smack *nsp = smack_cred(new);
/*
* Allow the degenerate case where the new Smack value is
* the same as the current Smack value.
*/
if (tsp->smk_task == nsp->smk_task)
return 0;
if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
return 0;
return -EPERM;
}
/**
* smack_uring_sqpoll - check if a io_uring polling thread can be created
*
* Check to see if the current task is allowed to create a new io_uring
* kernel polling thread.
*/
static int smack_uring_sqpoll(void)
{
if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred()))
return 0;
return -EPERM;
}
/**
* smack_uring_cmd - check on file operations for io_uring
* @ioucmd: the command in question
*
* Make a best guess about whether a io_uring "command" should
* be allowed. Use the same logic used for determining if the
* file could be opened for read in the absence of better criteria.
*/
static int smack_uring_cmd(struct io_uring_cmd *ioucmd)
{
struct file *file = ioucmd->file;
struct smk_audit_info ad;
struct task_smack *tsp;
struct inode *inode;
int rc;
if (!file)
return -EINVAL;
tsp = smack_cred(file->f_cred);
inode = file_inode(file);
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
return rc;
}
#endif /* CONFIG_IO_URING */
struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
.lbs_cred = sizeof(struct task_smack),
.lbs_file = sizeof(struct smack_known *),
.lbs_inode = sizeof(struct inode_smack),
.lbs_ipc = sizeof(struct smack_known *),
.lbs_msg_msg = sizeof(struct smack_known *),
.lbs_superblock = sizeof(struct superblock_smack),
};
static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
LSM_HOOK_INIT(syslog, smack_syslog),
LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec),
LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
LSM_HOOK_INIT(inode_init_security, smack_inode_init_security),
LSM_HOOK_INIT(inode_link, smack_inode_link),
LSM_HOOK_INIT(inode_unlink, smack_inode_unlink),
LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir),
LSM_HOOK_INIT(inode_rename, smack_inode_rename),
LSM_HOOK_INIT(inode_permission, smack_inode_permission),
LSM_HOOK_INIT(inode_setattr, smack_inode_setattr),
LSM_HOOK_INIT(inode_getattr, smack_inode_getattr),
LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr),
LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr),
LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr),
LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr),
LSM_HOOK_INIT(inode_set_acl, smack_inode_set_acl),
LSM_HOOK_INIT(inode_get_acl, smack_inode_get_acl),
LSM_HOOK_INIT(inode_remove_acl, smack_inode_remove_acl),
LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity),
LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity),
LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity),
LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid),
LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security),
LSM_HOOK_INIT(file_ioctl, smack_file_ioctl),
LSM_HOOK_INIT(file_lock, smack_file_lock),
LSM_HOOK_INIT(file_fcntl, smack_file_fcntl),
LSM_HOOK_INIT(mmap_file, smack_mmap_file),
LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner),
LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask),
LSM_HOOK_INIT(file_receive, smack_file_receive),
LSM_HOOK_INIT(file_open, smack_file_open),
LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank),
LSM_HOOK_INIT(cred_free, smack_cred_free),
LSM_HOOK_INIT(cred_prepare, smack_cred_prepare),
LSM_HOOK_INIT(cred_transfer, smack_cred_transfer),
LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid),
LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as),
LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as),
LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
LSM_HOOK_INIT(task_getsid, smack_task_getsid),
LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj),
LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj),
LSM_HOOK_INIT(task_setnice, smack_task_setnice),
LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),
LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler),
LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler),
LSM_HOOK_INIT(task_movememory, smack_task_movememory),
LSM_HOOK_INIT(task_kill, smack_task_kill),
LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),
LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),
LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security),
LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate),
LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl),
LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd),
LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv),
LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security),
LSM_HOOK_INIT(shm_associate, smack_shm_associate),
LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl),
LSM_HOOK_INIT(shm_shmat, smack_shm_shmat),
LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security),
LSM_HOOK_INIT(sem_associate, smack_sem_associate),
LSM_HOOK_INIT(sem_semctl, smack_sem_semctl),
LSM_HOOK_INIT(sem_semop, smack_sem_semop),
LSM_HOOK_INIT(d_instantiate, smack_d_instantiate),
LSM_HOOK_INIT(getprocattr, smack_getprocattr),
LSM_HOOK_INIT(setprocattr, smack_setprocattr),
LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect),
LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair),
#ifdef SMACK_IPV6_PORT_LABELING
LSM_HOOK_INIT(socket_bind, smack_socket_bind),
#endif
LSM_HOOK_INIT(socket_connect, smack_socket_connect),
LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security),
LSM_HOOK_INIT(sock_graft, smack_sock_graft),
LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
/* key management security hooks */
#ifdef CONFIG_KEYS
LSM_HOOK_INIT(key_alloc, smack_key_alloc),
LSM_HOOK_INIT(key_free, smack_key_free),
LSM_HOOK_INIT(key_permission, smack_key_permission),
LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
#ifdef CONFIG_KEY_NOTIFICATIONS
LSM_HOOK_INIT(watch_key, smack_watch_key),
#endif
#endif /* CONFIG_KEYS */
#ifdef CONFIG_WATCH_QUEUE
LSM_HOOK_INIT(post_notification, smack_post_notification),
#endif
/* Audit hooks */
#ifdef CONFIG_AUDIT
LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init),
LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known),
LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match),
#endif /* CONFIG_AUDIT */
LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up),
LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr),
LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as),
#ifdef CONFIG_IO_URING
LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds),
LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll),
LSM_HOOK_INIT(uring_cmd, smack_uring_cmd),
#endif
};
static __init void init_smack_known_list(void)
{
/*
* Initialize rule list locks
*/
mutex_init(&smack_known_huh.smk_rules_lock);
mutex_init(&smack_known_hat.smk_rules_lock);
mutex_init(&smack_known_floor.smk_rules_lock);
mutex_init(&smack_known_star.smk_rules_lock);
mutex_init(&smack_known_web.smk_rules_lock);
/*
* Initialize rule lists
*/
INIT_LIST_HEAD(&smack_known_huh.smk_rules);
INIT_LIST_HEAD(&smack_known_hat.smk_rules);
INIT_LIST_HEAD(&smack_known_star.smk_rules);
INIT_LIST_HEAD(&smack_known_floor.smk_rules);
INIT_LIST_HEAD(&smack_known_web.smk_rules);
/*
* Create the known labels list
*/
smk_insert_entry(&smack_known_huh);
smk_insert_entry(&smack_known_hat);
smk_insert_entry(&smack_known_star);
smk_insert_entry(&smack_known_floor);
smk_insert_entry(&smack_known_web);
}
/**
* smack_init - initialize the smack system
*
* Returns 0 on success, -ENOMEM is there's no memory
*/
static __init int smack_init(void)
{
struct cred *cred = (struct cred *) current->cred;
struct task_smack *tsp;
smack_rule_cache = KMEM_CACHE(smack_rule, 0);
if (!smack_rule_cache)
return -ENOMEM;
/*
* Set the security state for the initial task.
*/
tsp = smack_cred(cred);
init_task_smack(tsp, &smack_known_floor, &smack_known_floor);
/*
* Register with LSM
*/
security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
smack_enabled = 1;
pr_info("Smack: Initializing.\n");
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
pr_info("Smack: Netfilter enabled.\n");
#endif
#ifdef SMACK_IPV6_PORT_LABELING
pr_info("Smack: IPv6 port labeling enabled.\n");
#endif
#ifdef SMACK_IPV6_SECMARK_LABELING
pr_info("Smack: IPv6 Netfilter enabled.\n");
#endif
/* initialize the smack_known_list */
init_smack_known_list();
return 0;
}
/*
* Smack requires early initialization in order to label
* all processes and objects when they are created.
*/
DEFINE_LSM(smack) = {
.name = "smack",
.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
.blobs = &smack_blob_sizes,
.init = smack_init,
};
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