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linux_dsm_epyc7002/security/smack/smack_lsm.c
Al Viro 3f7036a071 switch security_inode_getattr() to struct path * 
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:24:32 -04:00

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/*
* 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.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2,
* as published by the Free Software Foundation.
*/
#include <linux/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/slab.h>
#include <linux/mutex.h>
#include <linux/pipe_fs_i.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 "smack.h"
#define TRANS_TRUE "TRUE"
#define TRANS_TRUE_SIZE 4
#define SMK_CONNECTING 0
#define SMK_RECEIVING 1
#define SMK_SENDING 2
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
LIST_HEAD(smk_ipv6_port_list);
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
static struct kmem_cache *smack_inode_cache;
int smack_enabled;
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
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;
smk_bu_mode(mode, acc);
pr_info("Smack Bringup: (%s %s %s) %s\n",
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 = current_security();
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
smk_bu_mode(mode, acc);
pr_info("Smack Bringup: (%s %s %s) %s %s\n",
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 = current_security();
struct smack_known *smk_task = smk_of_task_struct(otp);
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
smk_bu_mode(mode, acc);
pr_info("Smack Bringup: (%s %s %s) %s to %s\n",
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 = current_security();
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
smk_bu_mode(mode, acc);
pr_info("Smack Bringup: (%s %s %s) inode=(%s %ld) %s\n",
tsp->smk_task->smk_known, smk_of_inode(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 = current_security();
struct smack_known *sskp = tsp->smk_task;
struct inode *inode = file_inode(file);
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
smk_bu_mode(mode, acc);
pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
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 = cred->security;
struct smack_known *sskp = tsp->smk_task;
struct inode *inode = file->f_inode;
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
smk_bu_mode(mode, acc);
pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
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
* or NULL if there was no label to fetch.
*/
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_op->getxattr == NULL)
return NULL;
buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
if (buffer == NULL)
return NULL;
rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
if (rc > 0)
skp = smk_import_entry(buffer, rc);
kfree(buffer);
return skp;
}
/**
* new_inode_smack - allocate an inode security blob
* @skp: a pointer to the Smack label entry to use in the blob
*
* Returns the new blob or NULL if there's no memory available
*/
struct inode_smack *new_inode_smack(struct smack_known *skp)
{
struct inode_smack *isp;
isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS);
if (isp == NULL)
return NULL;
isp->smk_inode = skp;
isp->smk_flags = 0;
mutex_init(&isp->smk_lock);
return isp;
}
/**
* new_task_smack - allocate a task security blob
* @task: a pointer to the Smack label for the running task
* @forked: a pointer to the Smack label for the forked task
* @gfp: type of the memory for the allocation
*
* Returns the new blob or NULL if there's no memory available
*/
static struct task_smack *new_task_smack(struct smack_known *task,
struct smack_known *forked, gfp_t gfp)
{
struct task_smack *tsp;
tsp = kzalloc(sizeof(struct task_smack), gfp);
if (tsp == NULL)
return NULL;
tsp->smk_task = task;
tsp->smk_forked = forked;
INIT_LIST_HEAD(&tsp->smk_rules);
mutex_init(&tsp->smk_rules_lock);
return tsp;
}
/**
* 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;
INIT_LIST_HEAD(nhead);
list_for_each_entry_rcu(orp, ohead, list) {
nrp = kzalloc(sizeof(struct smack_rule), gfp);
if (nrp == NULL) {
rc = -ENOMEM;
break;
}
*nrp = *orp;
list_add_rcu(&nrp->list, nhead);
}
return rc;
}
/**
* 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)
{
switch (mode) {
case PTRACE_MODE_READ:
return MAY_READ;
case PTRACE_MODE_ATTACH:
return MAY_READWRITE;
}
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;
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();
tsp = __task_cred(tracer)->security;
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 (capable(CAP_SYS_PTRACE))
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)
{
int rc;
struct smack_known *skp;
rc = cap_ptrace_access_check(ctp, mode);
if (rc != 0)
return rc;
skp = smk_of_task_struct(ctp);
rc = smk_ptrace_rule_check(current, skp, mode, __func__);
return rc;
}
/**
* 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)
{
int rc;
struct smack_known *skp;
rc = cap_ptrace_traceme(ptp);
if (rc != 0)
return rc;
skp = smk_of_task(current_security());
rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
return rc;
}
/**
* smack_syslog - Smack approval on syslog
* @type: message type
*
* 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;
sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
if (sbsp == NULL)
return -ENOMEM;
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_initialized will be zero from kzalloc.
*/
sb->s_security = sbsp;
return 0;
}
/**
* smack_sb_free_security - free a superblock blob
* @sb: the superblock getting the blob
*
*/
static void smack_sb_free_security(struct super_block *sb)
{
kfree(sb->s_security);
sb->s_security = NULL;
}
/**
* smack_sb_copy_data - copy mount options data for processing
* @orig: where to start
* @smackopts: mount options string
*
* Returns 0 on success or -ENOMEM on error.
*
* Copy the Smack specific mount options out of the mount
* options list.
*/
static int smack_sb_copy_data(char *orig, char *smackopts)
{
char *cp, *commap, *otheropts, *dp;
otheropts = (char *)get_zeroed_page(GFP_KERNEL);
if (otheropts == NULL)
return -ENOMEM;
for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
if (strstr(cp, SMK_FSDEFAULT) == cp)
dp = smackopts;
else if (strstr(cp, SMK_FSFLOOR) == cp)
dp = smackopts;
else if (strstr(cp, SMK_FSHAT) == cp)
dp = smackopts;
else if (strstr(cp, SMK_FSROOT) == cp)
dp = smackopts;
else if (strstr(cp, SMK_FSTRANS) == cp)
dp = smackopts;
else
dp = otheropts;
commap = strchr(cp, ',');
if (commap != NULL)
*commap = '\0';
if (*dp != '\0')
strcat(dp, ",");
strcat(dp, cp);
}
strcpy(orig, otheropts);
free_page((unsigned long)otheropts);
return 0;
}
/**
* smack_sb_kern_mount - Smack specific mount processing
* @sb: the file system superblock
* @flags: the mount flags
* @data: the smack mount options
*
* Returns 0 on success, an error code on failure
*/
static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
{
struct dentry *root = sb->s_root;
struct inode *inode = root->d_inode;
struct superblock_smack *sp = sb->s_security;
struct inode_smack *isp;
struct smack_known *skp;
char *op;
char *commap;
int transmute = 0;
int specified = 0;
if (sp->smk_initialized)
return 0;
sp->smk_initialized = 1;
for (op = data; op != NULL; op = commap) {
commap = strchr(op, ',');
if (commap != NULL)
*commap++ = '\0';
if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
op += strlen(SMK_FSHAT);
skp = smk_import_entry(op, 0);
if (skp != NULL) {
sp->smk_hat = skp;
specified = 1;
}
} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
op += strlen(SMK_FSFLOOR);
skp = smk_import_entry(op, 0);
if (skp != NULL) {
sp->smk_floor = skp;
specified = 1;
}
} else if (strncmp(op, SMK_FSDEFAULT,
strlen(SMK_FSDEFAULT)) == 0) {
op += strlen(SMK_FSDEFAULT);
skp = smk_import_entry(op, 0);
if (skp != NULL) {
sp->smk_default = skp;
specified = 1;
}
} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
op += strlen(SMK_FSROOT);
skp = smk_import_entry(op, 0);
if (skp != NULL) {
sp->smk_root = skp;
specified = 1;
}
} else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
op += strlen(SMK_FSTRANS);
skp = smk_import_entry(op, 0);
if (skp != NULL) {
sp->smk_root = skp;
transmute = 1;
specified = 1;
}
}
}
if (!smack_privileged(CAP_MAC_ADMIN)) {
/*
* Unprivileged mounts don't get to specify Smack values.
*/
if (specified)
return -EPERM;
/*
* Unprivileged mounts get root and default from the caller.
*/
skp = smk_of_current();
sp->smk_root = skp;
sp->smk_default = skp;
}
/*
* Initialize the root inode.
*/
isp = inode->i_security;
if (isp == NULL) {
isp = new_inode_smack(sp->smk_root);
if (isp == NULL)
return -ENOMEM;
inode->i_security = isp;
} else
isp->smk_inode = sp->smk_root;
if (transmute)
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 = dentry->d_sb->s_security;
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_set_creds - set creds for exec
* @bprm: the exec information
*
* Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
*/
static int smack_bprm_set_creds(struct linux_binprm *bprm)
{
struct inode *inode = file_inode(bprm->file);
struct task_smack *bsp = bprm->cred->security;
struct inode_smack *isp;
int rc;
rc = cap_bprm_set_creds(bprm);
if (rc != 0)
return rc;
if (bprm->cred_prepared)
return 0;
isp = inode->i_security;
if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
return 0;
if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
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;
} else if (bprm->unsafe)
return -EPERM;
bsp->smk_task = isp->smk_task;
bprm->per_clear |= PER_CLEAR_ON_SETID;
return 0;
}
/**
* smack_bprm_committing_creds - Prepare to install the new credentials
* from bprm.
*
* @bprm: binprm for exec
*/
static void smack_bprm_committing_creds(struct linux_binprm *bprm)
{
struct task_smack *bsp = bprm->cred->security;
if (bsp->smk_task != bsp->smk_forked)
current->pdeath_signal = 0;
}
/**
* smack_bprm_secureexec - Return the decision to use secureexec.
* @bprm: binprm for exec
*
* Returns 0 on success.
*/
static int smack_bprm_secureexec(struct linux_binprm *bprm)
{
struct task_smack *tsp = current_security();
int ret = cap_bprm_secureexec(bprm);
if (!ret && (tsp->smk_task != tsp->smk_forked))
ret = 1;
return ret;
}
/*
* Inode hooks
*/
/**
* smack_inode_alloc_security - allocate an inode blob
* @inode: the inode in need of a blob
*
* Returns 0 if it gets a blob, -ENOMEM otherwise
*/
static int smack_inode_alloc_security(struct inode *inode)
{
struct smack_known *skp = smk_of_current();
inode->i_security = new_inode_smack(skp);
if (inode->i_security == NULL)
return -ENOMEM;
return 0;
}
/**
* smack_inode_free_security - free an inode blob
* @inode: the inode with a blob
*
* Clears the blob pointer in inode
*/
static void smack_inode_free_security(struct inode *inode)
{
kmem_cache_free(smack_inode_cache, inode->i_security);
inode->i_security = NULL;
}
/**
* 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 = inode->i_security;
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(old_dentry->d_inode);
rc = smk_curacc(isp, MAY_WRITE, &ad);
rc = smk_bu_inode(old_dentry->d_inode, MAY_WRITE, rc);
if (rc == 0 && d_is_positive(new_dentry)) {
isp = smk_of_inode(new_dentry->d_inode);
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
rc = smk_curacc(isp, MAY_WRITE, &ad);
rc = smk_bu_inode(new_dentry->d_inode, 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 = dentry->d_inode;
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(dentry->d_inode), MAY_WRITE, &ad);
rc = smk_bu_inode(dentry->d_inode, 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(old_dentry->d_inode);
rc = smk_curacc(isp, MAY_READWRITE, &ad);
rc = smk_bu_inode(old_dentry->d_inode, MAY_READWRITE, rc);
if (rc == 0 && d_is_positive(new_dentry)) {
isp = smk_of_inode(new_dentry->d_inode);
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
rc = smk_curacc(isp, MAY_READWRITE, &ad);
rc = smk_bu_inode(new_dentry->d_inode, 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, -EACCES otherwise
*/
static int smack_inode_permission(struct inode *inode, int mask)
{
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;
/* 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(dentry->d_inode), MAY_WRITE, &ad);
rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
return rc;
}
/**
* smack_inode_getattr - Smack check for getting attributes
* @mnt: vfsmount of the object
* @dentry: the object
*
* 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 = path->dentry->d_inode;
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
* @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 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 (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(dentry->d_inode), MAY_WRITE, &ad);
rc = smk_bu_inode(dentry->d_inode, 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 = dentry->d_inode->i_security;
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 (skp != NULL)
isp->smk_inode = skp;
else
isp->smk_inode = &smack_known_invalid;
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
skp = smk_import_entry(value, size);
if (skp != NULL)
isp->smk_task = skp;
else
isp->smk_task = &smack_known_invalid;
} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
skp = smk_import_entry(value, size);
if (skp != NULL)
isp->smk_mmap = skp;
else
isp->smk_mmap = &smack_known_invalid;
}
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(dentry->d_inode), MAY_READ, &ad);
rc = smk_bu_inode(dentry->d_inode, MAY_READ, rc);
return rc;
}
/**
* smack_inode_removexattr - Smack check on removexattr
* @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 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(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(dentry->d_inode), MAY_WRITE, &ad);
rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc);
if (rc != 0)
return rc;
isp = dentry->d_inode->i_security;
/*
* Don't do anything special for these.
* XATTR_NAME_SMACKIPIN
* XATTR_NAME_SMACKIPOUT
* XATTR_NAME_SMACKEXEC
*/
if (strcmp(name, XATTR_NAME_SMACK) == 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_getsecurity - get smack xattrs
* @inode: the object
* @name: attribute name
* @buffer: where to put the result
* @alloc: unused
*
* Returns the size of the attribute or an error code
*/
static int smack_inode_getsecurity(const 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;
int ilen;
int rc = 0;
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
isp = smk_of_inode(inode);
ilen = strlen(isp->smk_known);
*buffer = isp->smk_known;
return ilen;
}
/*
* 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;
ilen = strlen(isp->smk_known);
if (rc == 0) {
*buffer = isp->smk_known;
rc = ilen;
}
return rc;
}
/**
* smack_inode_listsecurity - list the Smack attributes
* @inode: the object
* @buffer: where they go
* @buffer_size: size of buffer
*
* Returns 0 on success, -EINVAL otherwise
*/
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(const struct inode *inode, u32 *secid)
{
struct inode_smack *isp = inode->i_security;
*secid = isp->smk_inode->smk_secid;
}
/*
* File Hooks
*/
/**
* smack_file_permission - Smack check on file operations
* @file: unused
* @mask: unused
*
* Returns 0
*
* 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.
*/
static int smack_file_permission(struct file *file, int mask)
{
return 0;
}
/**
* 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 *skp = smk_of_current();
file->f_security = skp;
return 0;
}
/**
* smack_file_free_security - clear a file security blob
* @file: the object
*
* The security blob for a file is a pointer to the master
* label list, so no memory is freed.
*/
static void smack_file_free_security(struct file *file)
{
file->f_security = NULL;
}
/**
* 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);
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);
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);
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. The @file may be NULL, e.g.
* if mapping anonymous memory.
* @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.
* 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;
int may;
int mmay;
int tmay;
int rc;
if (file == NULL)
return 0;
isp = file_inode(file)->i_security;
if (isp->smk_mmap == NULL)
return 0;
mkp = isp->smk_mmap;
tsp = current_security();
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)
{
file->f_security = 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 *skp;
struct smack_known *tkp = smk_of_task(tsk->cred->security);
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 */
skp = file->f_security;
rc = smk_access(skp, tkp, MAY_WRITE, NULL);
rc = smk_bu_note("sigiotask", skp, tkp, MAY_WRITE, rc);
if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
rc = 0;
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_WRITE, 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);
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
/*
* 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
* @cred: task credential
*
* 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
*/
static int smack_file_open(struct file *file, const struct cred *cred)
{
struct task_smack *tsp = cred->security;
struct inode *inode = file_inode(file);
struct smk_audit_info ad;
int rc;
if (smack_privileged(CAP_MAC_OVERRIDE))
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_access(tsp->smk_task, smk_of_inode(inode), MAY_READ, &ad);
rc = smk_bu_credfile(cred, file, MAY_READ, rc);
return rc;
}
/*
* Task hooks
*/
/**
* smack_cred_alloc_blank - "allocate" blank task-level security credentials
* @new: 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)
{
struct task_smack *tsp;
tsp = new_task_smack(NULL, NULL, gfp);
if (tsp == NULL)
return -ENOMEM;
cred->security = tsp;
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 = cred->security;
struct smack_rule *rp;
struct list_head *l;
struct list_head *n;
if (tsp == NULL)
return;
cred->security = NULL;
list_for_each_safe(l, n, &tsp->smk_rules) {
rp = list_entry(l, struct smack_rule, list);
list_del(&rp->list);
kfree(rp);
}
kfree(tsp);
}
/**
* 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 = old->security;
struct task_smack *new_tsp;
int rc;
new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
if (new_tsp == NULL)
return -ENOMEM;
rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
if (rc != 0)
return rc;
new->security = new_tsp;
return 0;
}
/**
* 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 = old->security;
struct task_smack *new_tsp = new->security;
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_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 = new->security;
struct smack_known *skp = smack_from_secid(secid);
if (skp == NULL)
return -EINVAL;
new_tsp->smk_task = skp;
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 = inode->i_security;
struct task_smack *tsp = new->security;
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(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_task_getsecid - get the secid of the task
* @p: the object task
* @secid: where to put the result
*
* Sets the secid to contain a u32 version of the smack label.
*/
static void smack_task_getsecid(struct task_struct *p, u32 *secid)
{
struct smack_known *skp = smk_of_task_struct(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)
{
int rc;
rc = cap_task_setnice(p, nice);
if (rc == 0)
rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
return rc;
}
/**
* 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)
{
int rc;
rc = cap_task_setioprio(p, ioprio);
if (rc == 0)
rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
return rc;
}
/**
* 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
* @policy: unused
* @lp: unused
*
* Return 0 if read access is permitted
*/
static int smack_task_setscheduler(struct task_struct *p)
{
int rc;
rc = cap_task_setscheduler(p);
if (rc == 0)
rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
return rc;
}
/**
* 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
* @secid: identifies the smack to use in lieu of current's
*
* Return 0 if write access is permitted
*
* The secid behavior is an artifact of an SELinux hack
* in the USB code. Someday it may go away.
*/
static int smack_task_kill(struct task_struct *p, struct siginfo *info,
int sig, u32 secid)
{
struct smk_audit_info ad;
struct smack_known *skp;
struct smack_known *tkp = smk_of_task_struct(p);
int rc;
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 (secid == 0) {
rc = smk_curacc(tkp, MAY_WRITE, &ad);
rc = smk_bu_task(p, MAY_WRITE, rc);
return rc;
}
/*
* If the secid isn't 0 we're dealing with some USB IO
* specific behavior. This is not clean. For one thing
* we can't take privilege into account.
*/
skp = smack_from_secid(secid);
rc = smk_access(skp, tkp, MAY_WRITE, &ad);
rc = smk_bu_note("USB signal", skp, tkp, MAY_WRITE, rc);
return rc;
}
/**
* smack_task_wait - Smack access check for waiting
* @p: task to wait for
*
* Returns 0
*/
static int smack_task_wait(struct task_struct *p)
{
/*
* Allow the operation to succeed.
* Zombies are bad.
* In userless environments (e.g. phones) programs
* get marked with SMACK64EXEC and even if the parent
* and child shouldn't be talking the parent still
* may expect to know when the child exits.
*/
return 0;
}
/**
* 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 = inode->i_security;
struct smack_known *skp = smk_of_task_struct(p);
isp->smk_inode = skp;
}
/*
* 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;
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)
{
kfree(sk->sk_security);
}
/**
* smack_host_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_host_label(struct sockaddr_in *sip)
{
struct smk_netlbladdr *snp;
struct in_addr *siap = &sip->sin_addr;
if (siap->s_addr == 0)
return NULL;
list_for_each_entry_rcu(snp, &smk_netlbladdr_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.sin_addr)->s_addr ==
(siap->s_addr & (&snp->smk_mask)->s_addr)) {
/* we have found the special CIPSO option */
if (snp->smk_label == &smack_cipso_option)
return NULL;
return snp->smk_label;
}
return NULL;
}
/**
* smack_netlabel - Set the secattr on a socket
* @sk: the socket
* @labeled: socket label scheme
*
* Convert the outbound smack value (smk_out) to a
* secattr and attach it to the socket.
*
* Returns 0 on success or an error code
*/
static int smack_netlabel(struct sock *sk, int labeled)
{
struct smack_known *skp;
struct socket_smack *ssp = sk->sk_security;
int rc = 0;
/*
* Usually the netlabel code will handle changing the
* packet labeling based on the label.
* The case of a single label host is different, because
* a single label host should never get a labeled packet
* even though the label is usually associated with a packet
* label.
*/
local_bh_disable();
bh_lock_sock_nested(sk);
if (ssp->smk_out == smack_net_ambient ||
labeled == SMACK_UNLABELED_SOCKET)
netlbl_sock_delattr(sk);
else {
skp = ssp->smk_out;
rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
}
bh_unlock_sock(sk);
local_bh_enable();
return rc;
}
/**
* smack_netlbel_send - Set the secattr on a socket and perform 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 smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
{
struct smack_known *skp;
int rc;
int sk_lbl;
struct smack_known *hkp;
struct socket_smack *ssp = sk->sk_security;
struct smk_audit_info ad;
rcu_read_lock();
hkp = smack_host_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
sk_lbl = SMACK_UNLABELED_SOCKET;
skp = ssp->smk_out;
rc = smk_access(skp, hkp, MAY_WRITE, &ad);
rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
} else {
sk_lbl = SMACK_CIPSO_SOCKET;
rc = 0;
}
rcu_read_unlock();
if (rc != 0)
return rc;
return smack_netlabel(sk, sk_lbl);
}
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
/**
* 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.
*/
list_for_each_entry(spp, &smk_ipv6_port_list, list) {
if (sk != spp->smk_sock)
continue;
spp->smk_in = ssp->smk_in;
spp->smk_out = ssp->smk_out;
return;
}
/*
* A NULL address is only used for updating existing
* bound entries. If there isn't one, it's OK.
*/
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.
*/
list_for_each_entry(spp, &smk_ipv6_port_list, list) {
if (spp->smk_port != port)
continue;
spp->smk_port = port;
spp->smk_sock = sk;
spp->smk_in = ssp->smk_in;
spp->smk_out = ssp->smk_out;
return;
}
/*
* 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;
list_add(&spp->list, &smk_ipv6_port_list);
return;
}
/**
* smk_ipv6_port_check - check Smack port access
* @sock: socket
* @address: address
*
* Create or update the port list entry
*/
static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
int act)
{
__be16 *bep;
__be32 *be32p;
struct smk_port_label *spp;
struct socket_smack *ssp = sk->sk_security;
struct smack_known *skp;
unsigned short port = 0;
struct smack_known *object;
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
#endif
if (act == SMK_RECEIVING) {
skp = smack_net_ambient;
object = ssp->smk_in;
} else {
skp = ssp->smk_out;
object = smack_net_ambient;
}
/*
* Get the IP address and port from the address.
*/
port = ntohs(address->sin6_port);
bep = (__be16 *)(&address->sin6_addr);
be32p = (__be32 *)(&address->sin6_addr);
/*
* It's remote, so port lookup does no good.
*/
if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1)
goto auditout;
/*
* It's local so the send check has to have passed.
*/
if (act == SMK_RECEIVING) {
skp = &smack_known_web;
goto auditout;
}
list_for_each_entry(spp, &smk_ipv6_port_list, list) {
if (spp->smk_port != port)
continue;
object = spp->smk_in;
if (act == SMK_CONNECTING)
ssp->smk_packet = spp->smk_out;
break;
}
auditout:
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = sk->sk_family;
ad.a.u.net->dport = 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(skp, object, MAY_WRITE, &ad);
rc = smk_bu_note("IPv6 port check", skp, object, MAY_WRITE, rc);
return rc;
}
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
/**
* 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 = inode->i_security;
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 (skp == NULL)
return -EINVAL;
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_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
if (rc != 0)
printk(KERN_WARNING
"Smack: \"%s\" netlbl error %d.\n",
__func__, -rc);
}
} else
return -EOPNOTSUPP;
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
if (sock->sk->sk_family == PF_INET6)
smk_ipv6_port_label(sock, NULL);
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
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)
{
if (family != PF_INET || sock->sk == NULL)
return 0;
/*
* Set the outbound netlbl.
*/
return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
}
#ifndef CONFIG_SECURITY_SMACK_NETFILTER
/**
* 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
*/
static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
int addrlen)
{
#if IS_ENABLED(CONFIG_IPV6)
if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
smk_ipv6_port_label(sock, address);
#endif
return 0;
}
#endif /* !CONFIG_SECURITY_SMACK_NETFILTER */
/**
* 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;
switch (sock->sk->sk_family) {
case PF_INET:
if (addrlen < sizeof(struct sockaddr_in))
return -EINVAL;
rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
break;
case PF_INET6:
if (addrlen < sizeof(struct sockaddr_in6))
return -EINVAL;
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
SMK_CONNECTING);
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
break;
}
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 *skp = smk_of_current();
msg->security = skp;
return 0;
}
/**
* smack_msg_msg_free_security - Clear the security blob for msg_msg
* @msg: the object
*
* Clears the blob pointer
*/
static void smack_msg_msg_free_security(struct msg_msg *msg)
{
msg->security = NULL;
}
/**
* smack_of_shm - the smack pointer for the shm
* @shp: the object
*
* Returns a pointer to the smack value
*/
static struct smack_known *smack_of_shm(struct shmid_kernel *shp)
{
return (struct smack_known *)shp->shm_perm.security;
}
/**
* smack_shm_alloc_security - Set the security blob for shm
* @shp: the object
*
* Returns 0
*/
static int smack_shm_alloc_security(struct shmid_kernel *shp)
{
struct kern_ipc_perm *isp = &shp->shm_perm;
struct smack_known *skp = smk_of_current();
isp->security = skp;
return 0;
}
/**
* smack_shm_free_security - Clear the security blob for shm
* @shp: the object
*
* Clears the blob pointer
*/
static void smack_shm_free_security(struct shmid_kernel *shp)
{
struct kern_ipc_perm *isp = &shp->shm_perm;
isp->security = NULL;
}
/**
* smk_curacc_shm : check if current has access on shm
* @shp : the object
* @access : access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smk_curacc_shm(struct shmid_kernel *shp, int access)
{
struct smack_known *ssp = smack_of_shm(shp);
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
ad.a.u.ipc_id = shp->shm_perm.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
* @shp: the object
* @shmflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
{
int may;
may = smack_flags_to_may(shmflg);
return smk_curacc_shm(shp, may);
}
/**
* smack_shm_shmctl - Smack access check for shm
* @shp: 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 shmid_kernel *shp, int cmd)
{
int may;
switch (cmd) {
case IPC_STAT:
case SHM_STAT:
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(shp, may);
}
/**
* smack_shm_shmat - Smack access for shmat
* @shp: the object
* @shmaddr: unused
* @shmflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
int shmflg)
{
int may;
may = smack_flags_to_may(shmflg);
return smk_curacc_shm(shp, may);
}
/**
* smack_of_sem - the smack pointer for the sem
* @sma: the object
*
* Returns a pointer to the smack value
*/
static struct smack_known *smack_of_sem(struct sem_array *sma)
{
return (struct smack_known *)sma->sem_perm.security;
}
/**
* smack_sem_alloc_security - Set the security blob for sem
* @sma: the object
*
* Returns 0
*/
static int smack_sem_alloc_security(struct sem_array *sma)
{
struct kern_ipc_perm *isp = &sma->sem_perm;
struct smack_known *skp = smk_of_current();
isp->security = skp;
return 0;
}
/**
* smack_sem_free_security - Clear the security blob for sem
* @sma: the object
*
* Clears the blob pointer
*/
static void smack_sem_free_security(struct sem_array *sma)
{
struct kern_ipc_perm *isp = &sma->sem_perm;
isp->security = NULL;
}
/**
* smk_curacc_sem : check if current has access on sem
* @sma : the object
* @access : access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smk_curacc_sem(struct sem_array *sma, int access)
{
struct smack_known *ssp = smack_of_sem(sma);
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
ad.a.u.ipc_id = sma->sem_perm.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
* @sma: the object
* @semflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_sem_associate(struct sem_array *sma, int semflg)
{
int may;
may = smack_flags_to_may(semflg);
return smk_curacc_sem(sma, may);
}
/**
* smack_sem_shmctl - Smack access check for sem
* @sma: 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 sem_array *sma, int cmd)
{
int may;
switch (cmd) {
case GETPID:
case GETNCNT:
case GETZCNT:
case GETVAL:
case GETALL:
case IPC_STAT:
case SEM_STAT:
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(sma, may);
}
/**
* smack_sem_semop - Smack checks of semaphore operations
* @sma: 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 sem_array *sma, struct sembuf *sops,
unsigned nsops, int alter)
{
return smk_curacc_sem(sma, MAY_READWRITE);
}
/**
* smack_msg_alloc_security - Set the security blob for msg
* @msq: the object
*
* Returns 0
*/
static int smack_msg_queue_alloc_security(struct msg_queue *msq)
{
struct kern_ipc_perm *kisp = &msq->q_perm;
struct smack_known *skp = smk_of_current();
kisp->security = skp;
return 0;
}
/**
* smack_msg_free_security - Clear the security blob for msg
* @msq: the object
*
* Clears the blob pointer
*/
static void smack_msg_queue_free_security(struct msg_queue *msq)
{
struct kern_ipc_perm *kisp = &msq->q_perm;
kisp->security = NULL;
}
/**
* smack_of_msq - the smack pointer for the msq
* @msq: the object
*
* Returns a pointer to the smack label entry
*/
static struct smack_known *smack_of_msq(struct msg_queue *msq)
{
return (struct smack_known *)msq->q_perm.security;
}
/**
* smk_curacc_msq : helper to check if current has access on msq
* @msq : the msq
* @access : access requested
*
* return 0 if current has access, error otherwise
*/
static int smk_curacc_msq(struct msg_queue *msq, int access)
{
struct smack_known *msp = smack_of_msq(msq);
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
ad.a.u.ipc_id = msq->q_perm.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
* @msq: the object
* @msqflg: access requested
*
* Returns 0 if current has the requested access, error code otherwise
*/
static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
{
int may;
may = smack_flags_to_may(msqflg);
return smk_curacc_msq(msq, may);
}
/**
* smack_msg_queue_msgctl - Smack access check for msg_queue
* @msq: 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 msg_queue *msq, int cmd)
{
int may;
switch (cmd) {
case IPC_STAT:
case MSG_STAT:
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(msq, may);
}
/**
* smack_msg_queue_msgsnd - Smack access check for msg_queue
* @msq: 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 msg_queue *msq, struct msg_msg *msg,
int msqflg)
{
int may;
may = smack_flags_to_may(msqflg);
return smk_curacc_msq(msq, may);
}
/**
* smack_msg_queue_msgsnd - Smack access check for msg_queue
* @msq: 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 msg_queue *msq, struct msg_msg *msg,
struct task_struct *target, long type, int mode)
{
return smk_curacc_msq(msq, 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 *iskp = ipp->security;
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 *iskp = ipp->security;
*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 = inode->i_security;
mutex_lock(&isp->smk_lock);
/*
* If the inode is already instantiated
* take the quick way out
*/
if (isp->smk_flags & SMK_INODE_INSTANT)
goto unlockandout;
sbp = inode->i_sb;
sbsp = sbp->s_security;
/*
* 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:
/*
* 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;
default:
isp->smk_inode = sbsp->smk_root;
break;
}
isp->smk_flags |= SMK_INODE_INSTANT;
goto unlockandout;
}
/*
* 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 PIPEFS_MAGIC:
case SOCKFS_MAGIC:
case CGROUP_SUPER_MAGIC:
/*
* Casey says that it's a little embarrassing
* that the smack file system doesn't do
* extended attributes.
*
* Casey says pipes are easy (?)
*
* Socket access is controlled by the socket
* structures associated with the task involved.
*
* 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;
/*
* No break.
*
* 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.
*/
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_op->getxattr == NULL)
break;
/*
* Get the dentry for xattr.
*/
dp = dget(opt_dentry);
skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
if (skp != NULL)
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 = inode->i_op->setxattr(dp,
XATTR_NAME_SMACKTRANSMUTE,
TRANS_TRUE, TRANS_TRUE_SIZE,
0);
} else {
rc = inode->i_op->getxattr(dp,
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 (skp == &smack_known_star || skp == &smack_known_web)
skp = NULL;
isp->smk_task = skp;
skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
if (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);
unlockandout:
mutex_unlock(&isp->smk_lock);
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, char *name, char **value)
{
struct smack_known *skp = smk_of_task_struct(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
* @p: the object task
* @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(struct task_struct *p, char *name,
void *value, size_t size)
{
struct task_smack *tsp;
struct cred *new;
struct smack_known *skp;
/*
* Changing another process' Smack value is too dangerous
* and supports no sane use case.
*/
if (p != current)
return -EPERM;
if (!smack_privileged(CAP_MAC_ADMIN))
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 (skp == NULL)
return -EINVAL;
/*
* No process is ever allowed the web ("@") label.
*/
if (skp == &smack_known_web)
return -EPERM;
new = prepare_creds();
if (new == NULL)
return -ENOMEM;
tsp = new->security;
tsp->smk_task = skp;
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) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
int rc = 0;
/*
* Perfectly reasonable for this to be NULL
*/
if (sip == NULL)
return 0;
switch (sip->sin_family) {
case AF_INET:
rc = smack_netlabel_send(sock->sk, sip);
break;
case AF_INET6:
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
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;
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(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;
}
if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
/*
* Looks like a fallback, which gives us a secid.
*/
skp = smack_from_secid(sap->attr.secid);
/*
* This has got to be a bug because it is
* impossible to specify a fallback without
* specifying the label, which will ensure
* it has a secid, and the only way to get a
* secid is from a fallback.
*/
BUG_ON(skp == NULL);
return skp;
}
/*
* 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:
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_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 netlbl_lsm_secattr secattr;
struct socket_smack *ssp = sk->sk_security;
struct smack_known *skp = NULL;
int rc = 0;
struct smk_audit_info ad;
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
#endif
#if IS_ENABLED(CONFIG_IPV6)
struct sockaddr_in6 sadd;
int proto;
#endif /* CONFIG_IPV6 */
switch (sk->sk_family) {
case PF_INET:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
/*
* 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.
*/
if (skb && skb->secmark != 0) {
skp = smack_from_secid(skb->secmark);
goto access_check;
}
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
/*
* Translate what netlabel gave us.
*/
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
if (rc == 0)
skp = smack_from_secattr(&secattr, ssp);
else
skp = smack_net_ambient;
netlbl_secattr_destroy(&secattr);
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = sk->sk_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, 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_TCP)
break;
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
if (skb && skb->secmark != 0)
skp = smack_from_secid(skb->secmark);
else
skp = smack_net_ambient;
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = sk->sk_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);
#else /* CONFIG_SECURITY_SMACK_NETFILTER */
rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
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,
char __user *optval,
int __user *optlen, unsigned len)
{
struct socket_smack *ssp;
char *rcp = "";
int 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;
else if (copy_to_user(optval, rcp, slen) != 0)
rc = -EFAULT;
if (put_user(slen, optlen) != 0)
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 netlbl_lsm_secattr secattr;
struct socket_smack *ssp = NULL;
struct smack_known *skp;
int family = PF_UNSPEC;
u32 s = 0; /* 0 is the invalid secid */
int rc;
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:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
s = skb->secmark;
if (s != 0)
break;
#endif
/*
* Translate what netlabel gave us.
*/
if (sock != NULL && sock->sk != NULL)
ssp = sock->sk->sk_security;
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, family, &secattr);
if (rc == 0) {
skp = smack_from_secattr(&secattr, ssp);
s = skp->smk_secid;
}
netlbl_secattr_destroy(&secattr);
break;
#if IS_ENABLED(CONFIG_IPV6)
case PF_INET6:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
s = skb->secmark;
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
break;
#endif /* CONFIG_IPV6 */
}
*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(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 netlbl_lsm_secattr secattr;
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 */
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
/*
* 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.
*/
if (skb && skb->secmark != 0) {
skp = smack_from_secid(skb->secmark);
goto access_check;
}
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, family, &secattr);
if (rc == 0)
skp = smack_from_secattr(&secattr, ssp);
else
skp = &smack_known_huh;
netlbl_secattr_destroy(&secattr);
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif
#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_host_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(cred->security);
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
* @perm: requested key permissions
*
* 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, unsigned perm)
{
struct key *keyp;
struct smk_audit_info ad;
struct smack_known *tkp = smk_of_task(cred->security);
int request = 0;
int rc;
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;
#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
if (perm & KEY_NEED_READ)
request = MAY_READ;
if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
request = MAY_WRITE;
rc = smk_access(tkp, keyp->security, request, &ad);
rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
return rc;
}
#endif /* CONFIG_KEYS */
/*
* 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 (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
* @actx: audit context associated with the check
*
* 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 audit_context *actx)
{
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;
}
/**
* smack_audit_rule_free - free smack rule representation
* @vrule: rule to be freed.
*
* No memory was allocated.
*/
static void smack_audit_rule_free(void *vrule)
{
/* No-op */
}
#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;
}
/**
* smack_release_secctx - don't do anything.
* @secdata: unused
* @seclen: unused
*
* Exists to make sure nothing gets done, and properly
*/
static void smack_release_secctx(char *secdata, u32 seclen)
{
}
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(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
}
static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
{
int len = 0;
len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
if (len < 0)
return len;
*ctxlen = len;
return 0;
}
struct security_operations smack_ops = {
.name = "smack",
.ptrace_access_check = smack_ptrace_access_check,
.ptrace_traceme = smack_ptrace_traceme,
.syslog = smack_syslog,
.sb_alloc_security = smack_sb_alloc_security,
.sb_free_security = smack_sb_free_security,
.sb_copy_data = smack_sb_copy_data,
.sb_kern_mount = smack_sb_kern_mount,
.sb_statfs = smack_sb_statfs,
.bprm_set_creds = smack_bprm_set_creds,
.bprm_committing_creds = smack_bprm_committing_creds,
.bprm_secureexec = smack_bprm_secureexec,
.inode_alloc_security = smack_inode_alloc_security,
.inode_free_security = smack_inode_free_security,
.inode_init_security = smack_inode_init_security,
.inode_link = smack_inode_link,
.inode_unlink = smack_inode_unlink,
.inode_rmdir = smack_inode_rmdir,
.inode_rename = smack_inode_rename,
.inode_permission = smack_inode_permission,
.inode_setattr = smack_inode_setattr,
.inode_getattr = smack_inode_getattr,
.inode_setxattr = smack_inode_setxattr,
.inode_post_setxattr = smack_inode_post_setxattr,
.inode_getxattr = smack_inode_getxattr,
.inode_removexattr = smack_inode_removexattr,
.inode_getsecurity = smack_inode_getsecurity,
.inode_setsecurity = smack_inode_setsecurity,
.inode_listsecurity = smack_inode_listsecurity,
.inode_getsecid = smack_inode_getsecid,
.file_permission = smack_file_permission,
.file_alloc_security = smack_file_alloc_security,
.file_free_security = smack_file_free_security,
.file_ioctl = smack_file_ioctl,
.file_lock = smack_file_lock,
.file_fcntl = smack_file_fcntl,
.mmap_file = smack_mmap_file,
.mmap_addr = cap_mmap_addr,
.file_set_fowner = smack_file_set_fowner,
.file_send_sigiotask = smack_file_send_sigiotask,
.file_receive = smack_file_receive,
.file_open = smack_file_open,
.cred_alloc_blank = smack_cred_alloc_blank,
.cred_free = smack_cred_free,
.cred_prepare = smack_cred_prepare,
.cred_transfer = smack_cred_transfer,
.kernel_act_as = smack_kernel_act_as,
.kernel_create_files_as = smack_kernel_create_files_as,
.task_setpgid = smack_task_setpgid,
.task_getpgid = smack_task_getpgid,
.task_getsid = smack_task_getsid,
.task_getsecid = smack_task_getsecid,
.task_setnice = smack_task_setnice,
.task_setioprio = smack_task_setioprio,
.task_getioprio = smack_task_getioprio,
.task_setscheduler = smack_task_setscheduler,
.task_getscheduler = smack_task_getscheduler,
.task_movememory = smack_task_movememory,
.task_kill = smack_task_kill,
.task_wait = smack_task_wait,
.task_to_inode = smack_task_to_inode,
.ipc_permission = smack_ipc_permission,
.ipc_getsecid = smack_ipc_getsecid,
.msg_msg_alloc_security = smack_msg_msg_alloc_security,
.msg_msg_free_security = smack_msg_msg_free_security,
.msg_queue_alloc_security = smack_msg_queue_alloc_security,
.msg_queue_free_security = smack_msg_queue_free_security,
.msg_queue_associate = smack_msg_queue_associate,
.msg_queue_msgctl = smack_msg_queue_msgctl,
.msg_queue_msgsnd = smack_msg_queue_msgsnd,
.msg_queue_msgrcv = smack_msg_queue_msgrcv,
.shm_alloc_security = smack_shm_alloc_security,
.shm_free_security = smack_shm_free_security,
.shm_associate = smack_shm_associate,
.shm_shmctl = smack_shm_shmctl,
.shm_shmat = smack_shm_shmat,
.sem_alloc_security = smack_sem_alloc_security,
.sem_free_security = smack_sem_free_security,
.sem_associate = smack_sem_associate,
.sem_semctl = smack_sem_semctl,
.sem_semop = smack_sem_semop,
.d_instantiate = smack_d_instantiate,
.getprocattr = smack_getprocattr,
.setprocattr = smack_setprocattr,
.unix_stream_connect = smack_unix_stream_connect,
.unix_may_send = smack_unix_may_send,
.socket_post_create = smack_socket_post_create,
#ifndef CONFIG_SECURITY_SMACK_NETFILTER
.socket_bind = smack_socket_bind,
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
.socket_connect = smack_socket_connect,
.socket_sendmsg = smack_socket_sendmsg,
.socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
.socket_getpeersec_stream = smack_socket_getpeersec_stream,
.socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
.sk_alloc_security = smack_sk_alloc_security,
.sk_free_security = smack_sk_free_security,
.sock_graft = smack_sock_graft,
.inet_conn_request = smack_inet_conn_request,
.inet_csk_clone = smack_inet_csk_clone,
/* key management security hooks */
#ifdef CONFIG_KEYS
.key_alloc = smack_key_alloc,
.key_free = smack_key_free,
.key_permission = smack_key_permission,
#endif /* CONFIG_KEYS */
/* Audit hooks */
#ifdef CONFIG_AUDIT
.audit_rule_init = smack_audit_rule_init,
.audit_rule_known = smack_audit_rule_known,
.audit_rule_match = smack_audit_rule_match,
.audit_rule_free = smack_audit_rule_free,
#endif /* CONFIG_AUDIT */
.ismaclabel = smack_ismaclabel,
.secid_to_secctx = smack_secid_to_secctx,
.secctx_to_secid = smack_secctx_to_secid,
.release_secctx = smack_release_secctx,
.inode_notifysecctx = smack_inode_notifysecctx,
.inode_setsecctx = smack_inode_setsecctx,
.inode_getsecctx = smack_inode_getsecctx,
};
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_invalid.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_invalid.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_invalid);
smk_insert_entry(&smack_known_web);
}
/**
* smack_init - initialize the smack system
*
* Returns 0
*/
static __init int smack_init(void)
{
struct cred *cred;
struct task_smack *tsp;
if (!security_module_enable(&smack_ops))
return 0;
smack_enabled = 1;
smack_inode_cache = KMEM_CACHE(inode_smack, 0);
if (!smack_inode_cache)
return -ENOMEM;
tsp = new_task_smack(&smack_known_floor, &smack_known_floor,
GFP_KERNEL);
if (tsp == NULL) {
kmem_cache_destroy(smack_inode_cache);
return -ENOMEM;
}
printk(KERN_INFO "Smack: Initializing.\n");
/*
* Set the security state for the initial task.
*/
cred = (struct cred *) current->cred;
cred->security = tsp;
/* initialize the smack_known_list */
init_smack_known_list();
/*
* Register with LSM
*/
if (register_security(&smack_ops))
panic("smack: Unable to register with kernel.\n");
return 0;
}
/*
* Smack requires early initialization in order to label
* all processes and objects when they are created.
*/
security_initcall(smack_init);
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