blob: 319add31b4a4ee7b5464d2a15782289ecb110ce7 [file] [log] [blame]
/*
* 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 <linux/parser.h>
#include "smack.h"
#define TRANS_TRUE "TRUE"
#define TRANS_TRUE_SIZE 4
#define SMK_CONNECTING 0
#define SMK_RECEIVING 1
#define SMK_SENDING 2
#ifdef SMACK_IPV6_PORT_LABELING
DEFINE_MUTEX(smack_ipv6_lock);
static LIST_HEAD(smk_ipv6_port_list);
#endif
static struct kmem_cache *smack_inode_cache;
int smack_enabled;
static const match_table_t smk_mount_tokens = {
{Opt_fsdefault, SMK_FSDEFAULT "%s"},
{Opt_fsfloor, SMK_FSFLOOR "%s"},
{Opt_fshat, SMK_FSHAT "%s"},
{Opt_fsroot, SMK_FSROOT "%s"},
{Opt_fstransmute, SMK_FSTRANS "%s"},
{Opt_error, NULL},
};
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static char *smk_bu_mess[] = {
"Bringup Error", /* Unused */
"Bringup", /* SMACK_BRINGUP_ALLOW */
"Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */
"Unconfined Object", /* SMACK_UNCONFINED_OBJECT */
};
static void smk_bu_mode(int mode, char *s)
{
int i = 0;
if (mode & MAY_READ)
s[i++] = 'r';
if (mode & MAY_WRITE)
s[i++] = 'w';
if (mode & MAY_EXEC)
s[i++] = 'x';
if (mode & MAY_APPEND)
s[i++] = 'a';
if (mode & MAY_TRANSMUTE)
s[i++] = 't';
if (mode & MAY_LOCK)
s[i++] = 'l';
if (i == 0)
s[i++] = '-';
s[i] = '\0';
}
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_note(char *note, struct smack_known *sskp,
struct smack_known *oskp, int mode, int rc)
{
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
sskp->smk_known, oskp->smk_known, acc, note);
return 0;
}
#else
#define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_current(char *note, struct smack_known *oskp,
int mode, int rc)
{
struct task_smack *tsp = current_security();
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
tsp->smk_task->smk_known, oskp->smk_known,
acc, current->comm, note);
return 0;
}
#else
#define smk_bu_current(note, oskp, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_task(struct task_struct *otp, int mode, int rc)
{
struct task_smack *tsp = current_security();
struct smack_known *smk_task = smk_of_task_struct(otp);
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
tsp->smk_task->smk_known, smk_task->smk_known, acc,
current->comm, otp->comm);
return 0;
}
#else
#define smk_bu_task(otp, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_inode(struct inode *inode, int mode, int rc)
{
struct task_smack *tsp = current_security();
struct inode_smack *isp = inode->i_security;
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (isp->smk_flags & SMK_INODE_IMPURE)
pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
inode->i_sb->s_id, inode->i_ino, current->comm);
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
if (rc == SMACK_UNCONFINED_SUBJECT &&
(mode & (MAY_WRITE | MAY_APPEND)))
isp->smk_flags |= SMK_INODE_IMPURE;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, current->comm);
return 0;
}
#else
#define smk_bu_inode(inode, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_file(struct file *file, int mode, int rc)
{
struct task_smack *tsp = current_security();
struct smack_known *sskp = tsp->smk_task;
struct inode *inode = file_inode(file);
struct inode_smack *isp = inode->i_security;
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (isp->smk_flags & SMK_INODE_IMPURE)
pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
inode->i_sb->s_id, inode->i_ino, current->comm);
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, file,
current->comm);
return 0;
}
#else
#define smk_bu_file(file, mode, RC) (RC)
#endif
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static int smk_bu_credfile(const struct cred *cred, struct file *file,
int mode, int rc)
{
struct task_smack *tsp = cred->security;
struct smack_known *sskp = tsp->smk_task;
struct inode *inode = file_inode(file);
struct inode_smack *isp = inode->i_security;
char acc[SMK_NUM_ACCESS_TYPE + 1];
if (isp->smk_flags & SMK_INODE_IMPURE)
pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
inode->i_sb->s_id, inode->i_ino, current->comm);
if (rc <= 0)
return rc;
if (rc > SMACK_UNCONFINED_OBJECT)
rc = 0;
smk_bu_mode(mode, acc);
pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, file,
current->comm);
return 0;
}
#else
#define smk_bu_credfile(cred, file, mode, RC) (RC)
#endif
/**
* smk_fetch - Fetch the smack label from a file.
* @name: type of the label (attribute)
* @ip: a pointer to the inode
* @dp: a pointer to the dentry
*
* Returns a pointer to the master list entry for the Smack label,
* NULL if there was no label to fetch, or an error code.
*/
static struct smack_known *smk_fetch(const char *name, struct inode *ip,
struct dentry *dp)
{
int rc;
char *buffer;
struct smack_known *skp = NULL;
if (!(ip->i_opflags & IOP_XATTR))
return ERR_PTR(-EOPNOTSUPP);
buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
if (buffer == NULL)
return ERR_PTR(-ENOMEM);
rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
if (rc < 0)
skp = ERR_PTR(rc);
else if (rc == 0)
skp = NULL;
else
skp = smk_import_entry(buffer, rc);
kfree(buffer);
return skp;
}
/**
* 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
*/
static 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);
INIT_LIST_HEAD(&tsp->smk_relabel);
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;
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_copy_relabel - copy smk_relabel labels list
* @nhead: new rules header pointer
* @ohead: old rules header pointer
* @gfp: type of the memory for the allocation
*
* Returns 0 on success, -ENOMEM on error
*/
static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
gfp_t gfp)
{
struct smack_known_list_elem *nklep;
struct smack_known_list_elem *oklep;
list_for_each_entry(oklep, ohead, list) {
nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
if (nklep == NULL) {
smk_destroy_label_list(nhead);
return -ENOMEM;
}
nklep->smk_label = oklep->smk_label;
list_add(&nklep->list, nhead);
}
return 0;
}
/**
* smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
* @mode - input mode in form of PTRACE_MODE_*
*
* Returns a converted MAY_* mode usable by smack rules
*/
static inline unsigned int smk_ptrace_mode(unsigned int mode)
{
if (mode & PTRACE_MODE_ATTACH)
return MAY_READWRITE;
if (mode & PTRACE_MODE_READ)
return MAY_READ;
return 0;
}
/**
* smk_ptrace_rule_check - helper for ptrace access
* @tracer: tracer process
* @tracee_known: label entry of the process that's about to be traced
* @mode: ptrace attachment mode (PTRACE_MODE_*)
* @func: name of the function that called us, used for audit
*
* Returns 0 on access granted, -error on error
*/
static int smk_ptrace_rule_check(struct task_struct *tracer,
struct smack_known *tracee_known,
unsigned int mode, const char *func)
{
int rc;
struct smk_audit_info ad, *saip = NULL;
struct task_smack *tsp;
struct smack_known *tracer_known;
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)
{
struct smack_known *skp;
skp = smk_of_task_struct(ctp);
return smk_ptrace_rule_check(current, skp, mode, __func__);
}
/**
* smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
* @ptp: parent task pointer
*
* Returns 0 if access is OK, an error code otherwise
*
* Do the capability checks, and require PTRACE_MODE_ATTACH.
*/
static int smack_ptrace_traceme(struct task_struct *ptp)
{
int rc;
struct smack_known *skp;
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_SB_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_parse_opts_str - parse Smack specific mount options
* @options: mount options string
* @opts: where to store converted mount opts
*
* Returns 0 on success or -ENOMEM on error.
*
* converts Smack specific mount options to generic security option format
*/
static int smack_parse_opts_str(char *options,
struct security_mnt_opts *opts)
{
char *p;
char *fsdefault = NULL;
char *fsfloor = NULL;
char *fshat = NULL;
char *fsroot = NULL;
char *fstransmute = NULL;
int rc = -ENOMEM;
int num_mnt_opts = 0;
int token;
opts->num_mnt_opts = 0;
if (!options)
return 0;
while ((p = strsep(&options, ",")) != NULL) {
substring_t args[MAX_OPT_ARGS];
if (!*p)
continue;
token = match_token(p, smk_mount_tokens, args);
switch (token) {
case Opt_fsdefault:
if (fsdefault)
goto out_opt_err;
fsdefault = match_strdup(&args[0]);
if (!fsdefault)
goto out_err;
break;
case Opt_fsfloor:
if (fsfloor)
goto out_opt_err;
fsfloor = match_strdup(&args[0]);
if (!fsfloor)
goto out_err;
break;
case Opt_fshat:
if (fshat)
goto out_opt_err;
fshat = match_strdup(&args[0]);
if (!fshat)
goto out_err;
break;
case Opt_fsroot:
if (fsroot)
goto out_opt_err;
fsroot = match_strdup(&args[0]);
if (!fsroot)
goto out_err;
break;
case Opt_fstransmute:
if (fstransmute)
goto out_opt_err;
fstransmute = match_strdup(&args[0]);
if (!fstransmute)
goto out_err;
break;
default:
rc = -EINVAL;
pr_warn("Smack: unknown mount option\n");
goto out_err;
}
}
opts->mnt_opts = kcalloc(NUM_SMK_MNT_OPTS, sizeof(char *), GFP_KERNEL);
if (!opts->mnt_opts)
goto out_err;
opts->mnt_opts_flags = kcalloc(NUM_SMK_MNT_OPTS, sizeof(int),
GFP_KERNEL);
if (!opts->mnt_opts_flags)
goto out_err;
if (fsdefault) {
opts->mnt_opts[num_mnt_opts] = fsdefault;
opts->mnt_opts_flags[num_mnt_opts++] = FSDEFAULT_MNT;
}
if (fsfloor) {
opts->mnt_opts[num_mnt_opts] = fsfloor;
opts->mnt_opts_flags[num_mnt_opts++] = FSFLOOR_MNT;
}
if (fshat) {
opts->mnt_opts[num_mnt_opts] = fshat;
opts->mnt_opts_flags[num_mnt_opts++] = FSHAT_MNT;
}
if (fsroot) {
opts->mnt_opts[num_mnt_opts] = fsroot;
opts->mnt_opts_flags[num_mnt_opts++] = FSROOT_MNT;
}
if (fstransmute) {
opts->mnt_opts[num_mnt_opts] = fstransmute;
opts->mnt_opts_flags[num_mnt_opts++] = FSTRANS_MNT;
}
opts->num_mnt_opts = num_mnt_opts;
return 0;
out_opt_err:
rc = -EINVAL;
pr_warn("Smack: duplicate mount options\n");
out_err:
kfree(fsdefault);
kfree(fsfloor);
kfree(fshat);
kfree(fsroot);
kfree(fstransmute);
return rc;
}
/**
* smack_set_mnt_opts - set Smack specific mount options
* @sb: the file system superblock
* @opts: Smack mount options
* @kern_flags: mount option from kernel space or user space
* @set_kern_flags: where to store converted mount opts
*
* Returns 0 on success, an error code on failure
*
* Allow filesystems with binary mount data to explicitly set Smack mount
* labels.
*/
static int smack_set_mnt_opts(struct super_block *sb,
struct security_mnt_opts *opts,
unsigned long kern_flags,
unsigned long *set_kern_flags)
{
struct dentry *root = sb->s_root;
struct inode *inode = d_backing_inode(root);
struct superblock_smack *sp = sb->s_security;
struct inode_smack *isp;
struct smack_known *skp;
int i;
int num_opts = opts->num_mnt_opts;
int transmute = 0;
if (sp->smk_flags & SMK_SB_INITIALIZED)
return 0;
if (!smack_privileged(CAP_MAC_ADMIN)) {
/*
* Unprivileged mounts don't get to specify Smack values.
*/
if (num_opts)
return -EPERM;
/*
* Unprivileged mounts get root and default from the caller.
*/
skp = smk_of_current();
sp->smk_root = skp;
sp->smk_default = skp;
/*
* For a handful of fs types with no user-controlled
* backing store it's okay to trust security labels
* in the filesystem. The rest are untrusted.
*/
if (sb->s_user_ns != &init_user_ns &&
sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
sb->s_magic != RAMFS_MAGIC) {
transmute = 1;
sp->smk_flags |= SMK_SB_UNTRUSTED;
}
}
sp->smk_flags |= SMK_SB_INITIALIZED;
for (i = 0; i < num_opts; i++) {
switch (opts->mnt_opts_flags[i]) {
case FSDEFAULT_MNT:
skp = smk_import_entry(opts->mnt_opts[i], 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_default = skp;
break;
case FSFLOOR_MNT:
skp = smk_import_entry(opts->mnt_opts[i], 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_floor = skp;
break;
case FSHAT_MNT:
skp = smk_import_entry(opts->mnt_opts[i], 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_hat = skp;
break;
case FSROOT_MNT:
skp = smk_import_entry(opts->mnt_opts[i], 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_root = skp;
break;
case FSTRANS_MNT:
skp = smk_import_entry(opts->mnt_opts[i], 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_root = skp;
transmute = 1;
break;
default:
break;
}
}
/*
* 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_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)
{
int rc = 0;
char *options = data;
struct security_mnt_opts opts;
security_init_mnt_opts(&opts);
if (!options)
goto out;
rc = smack_parse_opts_str(options, &opts);
if (rc)
goto out_err;
out:
rc = smack_set_mnt_opts(sb, &opts, 0, NULL);
out_err:
security_free_mnt_opts(&opts);
return rc;
}
/**
* 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;
struct superblock_smack *sbsp;
int rc;
if (bprm->called_set_creds)
return 0;
isp = inode->i_security;
if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
return 0;
sbsp = inode->i_sb->s_security;
if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
isp->smk_task != sbsp->smk_root)
return 0;
if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
struct task_struct *tracer;
rc = 0;
rcu_read_lock();
tracer = ptrace_parent(current);
if (likely(tracer != NULL))
rc = smk_ptrace_rule_check(tracer,
isp->smk_task,
PTRACE_MODE_ATTACH,
__func__);
rcu_read_unlock();
if (rc != 0)
return rc;
} else if (bprm->unsafe)
return -EPERM;
bsp->smk_task = isp->smk_task;
bprm->per_clear |= PER_CLEAR_ON_SETID;
/* Decide if this is a secure exec. */
if (bsp->smk_task != bsp->smk_forked)
bprm->secureexec = 1;
return 0;
}
/*
* Inode hooks
*/
/**
* smack_inode_alloc_security - allocate an inode blob
* @inode: the inode in need of a blob
*
* Returns 0 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_rcu - Free inode_smack blob from cache
* @head: the rcu_head for getting inode_smack pointer
*
* Call back function called from call_rcu() to free
* the i_security blob pointer in inode
*/
static void smack_inode_free_rcu(struct rcu_head *head)
{
struct inode_smack *issp;
issp = container_of(head, struct inode_smack, smk_rcu);
kmem_cache_free(smack_inode_cache, issp);
}
/**
* smack_inode_free_security - free an inode blob using call_rcu()
* @inode: the inode with a blob
*
* Clears the blob pointer in inode using RCU
*/
static void smack_inode_free_security(struct inode *inode)
{
struct inode_smack *issp = inode->i_security;
/*
* The inode may still be referenced in a path walk and
* a call to smack_inode_permission() can be made
* after smack_inode_free_security() is called.
* To avoid race condition free the i_security via RCU
* and leave the current inode->i_security pointer intact.
* The inode will be freed after the RCU grace period too.
*/
call_rcu(&issp->smk_rcu, smack_inode_free_rcu);
}
/**
* 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(d_backing_inode(old_dentry));
rc = smk_curacc(isp, MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
if (rc == 0 && d_is_positive(new_dentry)) {
isp = smk_of_inode(d_backing_inode(new_dentry));
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
rc = smk_curacc(isp, MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
}
return rc;
}
/**
* smack_inode_unlink - Smack check on inode deletion
* @dir: containing directory object
* @dentry: file to unlink
*
* Returns 0 if current can write the containing directory
* and the object, error code otherwise
*/
static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
{
struct inode *ip = d_backing_inode(dentry);
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
/*
* You need write access to the thing you're unlinking
*/
rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
rc = smk_bu_inode(ip, MAY_WRITE, rc);
if (rc == 0) {
/*
* You also need write access to the containing directory
*/
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
smk_ad_setfield_u_fs_inode(&ad, dir);
rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
rc = smk_bu_inode(dir, MAY_WRITE, rc);
}
return rc;
}
/**
* smack_inode_rmdir - Smack check on directory deletion
* @dir: containing directory object
* @dentry: directory to unlink
*
* Returns 0 if current can write the containing directory
* and the directory, error code otherwise
*/
static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
{
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
/*
* You need write access to the thing you're removing
*/
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
if (rc == 0) {
/*
* You also need write access to the containing directory
*/
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
smk_ad_setfield_u_fs_inode(&ad, dir);
rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
rc = smk_bu_inode(dir, MAY_WRITE, rc);
}
return rc;
}
/**
* smack_inode_rename - Smack check on rename
* @old_inode: unused
* @old_dentry: the old object
* @new_inode: unused
* @new_dentry: the new object
*
* Read and write access is required on both the old and
* new directories.
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_rename(struct inode *old_inode,
struct dentry *old_dentry,
struct inode *new_inode,
struct dentry *new_dentry)
{
int rc;
struct smack_known *isp;
struct smk_audit_info ad;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
isp = smk_of_inode(d_backing_inode(old_dentry));
rc = smk_curacc(isp, MAY_READWRITE, &ad);
rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
if (rc == 0 && d_is_positive(new_dentry)) {
isp = smk_of_inode(d_backing_inode(new_dentry));
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
rc = smk_curacc(isp, MAY_READWRITE, &ad);
rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
}
return rc;
}
/**
* smack_inode_permission - Smack version of permission()
* @inode: the inode in question
* @mask: the access requested
*
* This is the important Smack hook.
*
* Returns 0 if access is permitted, -EACCES otherwise
*/
static int smack_inode_permission(struct inode *inode, int mask)
{
struct superblock_smack *sbsp = inode->i_sb->s_security;
struct smk_audit_info ad;
int no_block = mask & MAY_NOT_BLOCK;
int rc;
mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
/*
* No permission to check. Existence test. Yup, it's there.
*/
if (mask == 0)
return 0;
if (sbsp->smk_flags & SMK_SB_UNTRUSTED) {
if (smk_of_inode(inode) != sbsp->smk_root)
return -EACCES;
}
/* May be droppable after audit */
if (no_block)
return -ECHILD;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
smk_ad_setfield_u_fs_inode(&ad, inode);
rc = smk_curacc(smk_of_inode(inode), mask, &ad);
rc = smk_bu_inode(inode, mask, rc);
return rc;
}
/**
* smack_inode_setattr - Smack check for setting attributes
* @dentry: the object
* @iattr: for the force flag
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct smk_audit_info ad;
int rc;
/*
* Need to allow for clearing the setuid bit.
*/
if (iattr->ia_valid & ATTR_FORCE)
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
return rc;
}
/**
* smack_inode_getattr - Smack check for getting attributes
* @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 = d_backing_inode(path->dentry);
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, *path);
rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
rc = smk_bu_inode(inode, MAY_READ, rc);
return rc;
}
/**
* smack_inode_setxattr - Smack check for setting xattrs
* @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 (IS_ERR(skp))
rc = PTR_ERR(skp);
else if (skp == NULL || (check_star &&
(skp == &smack_known_star || skp == &smack_known_web)))
rc = -EINVAL;
}
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
if (rc == 0) {
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
}
return rc;
}
/**
* smack_inode_post_setxattr - Apply the Smack update approved above
* @dentry: object
* @name: attribute name
* @value: attribute value
* @size: attribute size
* @flags: unused
*
* Set the pointer in the inode blob to the entry found
* in the master label list.
*/
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct smack_known *skp;
struct inode_smack *isp = d_backing_inode(dentry)->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 (!IS_ERR(skp))
isp->smk_inode = skp;
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
skp = smk_import_entry(value, size);
if (!IS_ERR(skp))
isp->smk_task = skp;
} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
skp = smk_import_entry(value, size);
if (!IS_ERR(skp))
isp->smk_mmap = skp;
}
return;
}
/**
* smack_inode_getxattr - Smack check on getxattr
* @dentry: the object
* @name: unused
*
* Returns 0 if access is permitted, an error code otherwise
*/
static int smack_inode_getxattr(struct dentry *dentry, const char *name)
{
struct smk_audit_info ad;
int rc;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
return rc;
}
/**
* smack_inode_removexattr - Smack check on removexattr
* @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(d_backing_inode(dentry)), MAY_WRITE, &ad);
rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
if (rc != 0)
return rc;
isp = d_backing_inode(dentry)->i_security;
/*
* Don't do anything special for these.
* XATTR_NAME_SMACKIPIN
* XATTR_NAME_SMACKIPOUT
*/
if (strcmp(name, XATTR_NAME_SMACK) == 0) {
struct super_block *sbp = dentry->d_sb;
struct superblock_smack *sbsp = sbp->s_security;
isp->smk_inode = sbsp->smk_default;
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
isp->smk_task = NULL;
else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
isp->smk_mmap = NULL;
else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
return 0;
}
/**
* smack_inode_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(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
*/
static int smack_inode_listsecurity(struct inode *inode, char *buffer,
size_t buffer_size)
{
int len = sizeof(XATTR_NAME_SMACK);
if (buffer != NULL && len <= buffer_size)
memcpy(buffer, XATTR_NAME_SMACK, len);
return len;
}
/**
* smack_inode_getsecid - Extract inode's security id
* @inode: inode to extract the info from
* @secid: where result will be saved
*/
static void smack_inode_getsecid(struct inode *inode, u32 *secid)
{
struct inode_smack *isp = inode->i_security;
*secid = isp->smk_inode->smk_secid;
}
/*
* File Hooks
*/
/*
* There is no smack_file_permission hook
*
* Should access checks be done on each read or write?
* UNICOS and SELinux say yes.
* Trusted Solaris, Trusted Irix, and just about everyone else says no.
*
* I'll say no for now. Smack does not do the frequent
* label changing that SELinux does.
*/
/**
* smack_file_alloc_security - assign a file security blob
* @file: the object
*
* The security blob for a file is a pointer to the master
* label list, so no allocation is done.
*
* f_security is the owner security information. It
* isn't used on file access checks, it's for send_sigio.
*
* Returns 0
*/
static int smack_file_alloc_security(struct file *file)
{
struct smack_known *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);
if (unlikely(IS_PRIVATE(inode)))
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
if (_IOC_DIR(cmd) & _IOC_WRITE) {
rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
rc = smk_bu_file(file, MAY_WRITE, rc);
}
if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
rc = smk_bu_file(file, MAY_READ, rc);
}
return rc;
}
/**
* smack_file_lock - Smack check on file locking
* @file: the object
* @cmd: unused
*
* Returns 0 if current has lock access, error code otherwise
*/
static int smack_file_lock(struct file *file, unsigned int cmd)
{
struct smk_audit_info ad;
int rc;
struct inode *inode = file_inode(file);
if (unlikely(IS_PRIVATE(inode)))
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
rc = smk_bu_file(file, MAY_LOCK, rc);
return rc;
}
/**
* smack_file_fcntl - Smack check on fcntl
* @file: the object
* @cmd: what action to check
* @arg: unused
*
* Generally these operations are harmless.
* File locking operations present an obvious mechanism
* for passing information, so they require write access.
*
* Returns 0 if current has access, error code otherwise
*/
static int smack_file_fcntl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct smk_audit_info ad;
int rc = 0;
struct inode *inode = file_inode(file);
if (unlikely(IS_PRIVATE(inode)))
return 0;
switch (cmd) {
case F_GETLK:
break;
case F_SETLK:
case F_SETLKW:
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
rc = smk_bu_file(file, MAY_LOCK, rc);
break;
case F_SETOWN:
case F_SETSIG:
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
rc = smk_bu_file(file, MAY_WRITE, rc);
break;
default:
break;
}
return rc;
}
/**
* smack_mmap_file :
* Check permissions for a mmap operation. 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;
struct superblock_smack *sbsp;
int may;
int mmay;
int tmay;
int rc;
if (file == NULL)
return 0;
if (unlikely(IS_PRIVATE(file_inode(file))))
return 0;
isp = file_inode(file)->i_security;
if (isp->smk_mmap == NULL)
return 0;
sbsp = file_inode(file)->i_sb->s_security;
if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
isp->smk_mmap != sbsp->smk_root)
return -EACCES;
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_DELIVER, NULL);
rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, 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_DELIVER, rc, &ad);
return rc;
}
/**
* smack_file_receive - Smack file receive check
* @file: the object
*
* Returns 0 if current has access, error code otherwise
*/
static int smack_file_receive(struct file *file)
{
int rc;
int may = 0;
struct smk_audit_info ad;
struct inode *inode = file_inode(file);
struct socket *sock;
struct task_smack *tsp;
struct socket_smack *ssp;
if (unlikely(IS_PRIVATE(inode)))
return 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
sock = SOCKET_I(inode);
ssp = sock->sk->sk_security;
tsp = current_security();
/*
* If the receiving process can't write to the
* passed socket or if the passed socket can't
* write to the receiving process don't accept
* the passed socket.
*/
rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad);
rc = smk_bu_file(file, may, rc);
if (rc < 0)
return rc;
rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad);
rc = smk_bu_file(file, may, rc);
return rc;
}
/*
* This code relies on bitmasks.
*/
if (file->f_mode & FMODE_READ)
may = MAY_READ;
if (file->f_mode & FMODE_WRITE)
may |= MAY_WRITE;
rc = smk_curacc(smk_of_inode(inode), may, &ad);
rc = smk_bu_file(file, may, rc);
return rc;
}
/**
* smack_file_open - Smack dentry open processing
* @file: the object
* @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;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
rc = smk_bu_credfile(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;
smk_destroy_label_list(&tsp->smk_relabel);
list_for_each_safe(l, n, &tsp->smk_rules) {
rp = list_entry(l, struct smack_rule, list);
list_del(&rp->list);
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;
new->security = new_tsp;
rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
if (rc != 0)
return rc;
rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
gfp);
if (rc != 0)
return rc;
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;
new_tsp->smk_task = smack_from_secid(secid);
return 0;
}
/**
* smack_kernel_create_files_as - Set the file creation label in a set of creds
* @new: points to the set of credentials to be modified
* @inode: points to the inode to use as a reference
*
* Set the file creation context in a set of credentials to the same
* as the objective context of the specified inode
*/
static int smack_kernel_create_files_as(struct cred *new,
struct inode *inode)
{
struct inode_smack *isp = 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)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_setioprio - Smack check on setting ioprio
* @p: the task object
* @ioprio: unused
*
* Return 0 if write access is permitted
*/
static int smack_task_setioprio(struct task_struct *p, int ioprio)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_getioprio - Smack check on reading ioprio
* @p: the task object
*
* Return 0 if read access is permitted
*/
static int smack_task_getioprio(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
* smack_task_setscheduler - Smack check on setting scheduler
* @p: the task object
* @policy: unused
* @lp: unused
*
* Return 0 if read access is permitted
*/
static int smack_task_setscheduler(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_getscheduler - Smack check on reading scheduler
* @p: the task object
*
* Return 0 if read access is permitted
*/
static int smack_task_getscheduler(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
* smack_task_movememory - Smack check on moving memory
* @p: the task object
*
* Return 0 if write access is permitted
*/
static int smack_task_movememory(struct task_struct *p)
{
return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
* smack_task_kill - Smack check on signal delivery
* @p: the task object
* @info: unused
* @sig: unused
* @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;
if (!sig)
return 0; /* null signal; existence test */
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, p);
/*
* Sending a signal requires that the sender
* can write the receiver.
*/
if (secid == 0) {
rc = smk_curacc(tkp, MAY_DELIVER, &ad);
rc = smk_bu_task(p, MAY_DELIVER, 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_DELIVER, &ad);
rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
return rc;
}
/**
* smack_task_to_inode - copy task smack into the inode blob
* @p: task to copy from
* @inode: inode to copy to
*
* Sets the smack pointer in the inode security blob
*/
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
{
struct inode_smack *isp = 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;
/*
* Sockets created by kernel threads receive web label.
*/
if (unlikely(current->flags & PF_KTHREAD)) {
ssp->smk_in = &smack_known_web;
ssp->smk_out = &smack_known_web;
} else {
ssp->smk_in = skp;
ssp->smk_out = skp;
}
ssp->smk_packet = NULL;
sk->sk_security = ssp;
return 0;
}
/**
* smack_sk_free_security - Free a socket blob
* @sk: the socket
*
* Clears the blob pointer
*/
static void smack_sk_free_security(struct sock *sk)
{
#ifdef SMACK_IPV6_PORT_LABELING
struct smk_port_label *spp;
if (sk->sk_family == PF_INET6) {
rcu_read_lock();
list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
if (spp->smk_sock != sk)
continue;
spp->smk_can_reuse = 1;
break;
}
rcu_read_unlock();
}
#endif
kfree(sk->sk_security);
}
/**
* smack_ipv4host_label - check host based restrictions
* @sip: the object end
*
* looks for host based access restrictions
*
* This version will only be appropriate for really small sets of single label
* hosts. The caller is responsible for ensuring that the RCU read lock is
* taken before calling this function.
*
* Returns the label of the far end or NULL if it's not special.
*/
static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
{
struct smk_net4addr *snp;
struct in_addr *siap = &sip->sin_addr;
if (siap->s_addr == 0)
return NULL;
list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
/*
* we break after finding the first match because
* the list is sorted from longest to shortest mask
* so we have found the most specific match
*/
if (snp->smk_host.s_addr ==
(siap->s_addr & snp->smk_mask.s_addr))
return snp->smk_label;
return NULL;
}
#if IS_ENABLED(CONFIG_IPV6)
/*
* smk_ipv6_localhost - Check for local ipv6 host address
* @sip: the address
*
* Returns boolean true if this is the localhost address
*/
static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
{
__be16 *be16p = (__be16 *)&sip->sin6_addr;
__be32 *be32p = (__be32 *)&sip->sin6_addr;
if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
ntohs(be16p[7]) == 1)
return true;
return false;
}
/**
* smack_ipv6host_label - check host based restrictions
* @sip: the object end
*
* looks for host based access restrictions
*
* This version will only be appropriate for really small sets of single label
* hosts. The caller is responsible for ensuring that the RCU read lock is
* taken before calling this function.
*
* Returns the label of the far end or NULL if it's not special.
*/
static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
{
struct smk_net6addr *snp;
struct in6_addr *sap = &sip->sin6_addr;
int i;
int found = 0;
/*
* It's local. Don't look for a host label.
*/
if (smk_ipv6_localhost(sip))
return NULL;
list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
/*
* If the label is NULL the entry has
* been renounced. Ignore it.
*/
if (snp->smk_label == NULL)
continue;
/*
* we break after finding the first match because
* the list is sorted from longest to shortest mask
* so we have found the most specific match
*/
for (found = 1, i = 0; i < 8; i++) {
if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
snp->smk_host.s6_addr16[i]) {
found = 0;
break;
}
}
if (found)
return snp->smk_label;
}
return NULL;
}
#endif /* CONFIG_IPV6 */
/**
* 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_ipv4host_label(sap);
if (hkp != NULL) {
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = sap->sin_family;
ad.a.u.net->dport = sap->sin_port;
ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
#endif
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)
/**
* smk_ipv6_check - check Smack access
* @subject: subject Smack label
* @object: object Smack label
* @address: address
* @act: the action being taken
*
* Check an IPv6 access
*/
static int smk_ipv6_check(struct smack_known *subject,
struct smack_known *object,
struct sockaddr_in6 *address, int act)
{
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
#endif
struct smk_audit_info ad;
int rc;
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = PF_INET6;
ad.a.u.net->dport = ntohs(address->sin6_port);
if (act == SMK_RECEIVING)
ad.a.u.net->v6info.saddr = address->sin6_addr;
else
ad.a.u.net->v6info.daddr = address->sin6_addr;
#endif
rc = smk_access(subject, object, MAY_WRITE, &ad);
rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
return rc;
}
#endif /* CONFIG_IPV6 */
#ifdef SMACK_IPV6_PORT_LABELING
/**
* smk_ipv6_port_label - Smack port access table management
* @sock: socket
* @address: address
*
* Create or update the port list entry
*/
static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
{
struct sock *sk = sock->sk;
struct sockaddr_in6 *addr6;
struct socket_smack *ssp = sock->sk->sk_security;
struct smk_port_label *spp;
unsigned short port = 0;
if (address == NULL) {
/*
* This operation is changing the Smack information
* on the bound socket. Take the changes to the port
* as well.
*/
rcu_read_lock();
list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
if (sk != spp->smk_sock)
continue;
spp->smk_in = ssp->smk_in;
spp->smk_out = ssp->smk_out;
rcu_read_unlock();
return;
}
/*
* A NULL address is only used for updating existing
* bound entries. If there isn't one, it's OK.
*/
rcu_read_unlock();
return;
}
addr6 = (struct sockaddr_in6 *)address;
port = ntohs(addr6->sin6_port);
/*
* This is a special case that is safely ignored.
*/
if (port == 0)
return;
/*
* Look for an existing port list entry.
* This is an indication that a port is getting reused.
*/
rcu_read_lock();
list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
if (spp->smk_port != port || spp->smk_sock_type != sock->type)
continue;
if (spp->smk_can_reuse != 1) {
rcu_read_unlock();
return;
}
spp->smk_port = port;
spp->smk_sock = sk;
spp->smk_in = ssp->smk_in;
spp->smk_out = ssp->smk_out;
spp->smk_can_reuse = 0;
rcu_read_unlock();
return;
}
rcu_read_unlock();
/*
* A new port entry is required.
*/
spp = kzalloc(sizeof(*spp), GFP_KERNEL);
if (spp == NULL)
return;
spp->smk_port = port;
spp->smk_sock = sk;
spp->smk_in = ssp->smk_in;
spp->smk_out = ssp->smk_out;
spp->smk_sock_type = sock->type;
spp->smk_can_reuse = 0;
mutex_lock(&smack_ipv6_lock);
list_add_rcu(&spp->list, &smk_ipv6_port_list);
mutex_unlock(&smack_ipv6_lock);
return;
}
/**
* smk_ipv6_port_check - check Smack port access
* @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)
{
struct smk_port_label *spp;
struct socket_smack *ssp = sk->sk_security;
struct smack_known *skp = NULL;
unsigned short port;
struct smack_known *object;
if (act == SMK_RECEIVING) {
skp = smack_ipv6host_label(address);
object = ssp->smk_in;
} else {
skp = ssp->smk_out;
object = smack_ipv6host_label(address);
}
/*
* The other end is a single label host.
*/
if (skp != NULL && object != NULL)
return smk_ipv6_check(skp, object, address, act);
if (skp == NULL)
skp = smack_net_ambient;
if (object == NULL)
object = smack_net_ambient;
/*
* It's remote, so port lookup does no good.
*/
if (!smk_ipv6_localhost(address))
return smk_ipv6_check(skp, object, address, act);
/*
* It's local so the send check has to have passed.
*/
if (act == SMK_RECEIVING)
return 0;
port = ntohs(address->sin6_port);
rcu_read_lock();
list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type)
continue;
object = spp->smk_in;
if (act == SMK_CONNECTING)
ssp->smk_packet = spp->smk_out;
break;
}
rcu_read_unlock();
return smk_ipv6_check(skp, object, address, act);
}
#endif /* SMACK_IPV6_PORT_LABELING */
/**
* 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 (IS_ERR(skp))
return PTR_ERR(skp);
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
nsp->smk_inode = skp;
nsp->smk_flags |= SMK_INODE_INSTANT;
return 0;
}
/*
* The rest of the Smack xattrs are only on sockets.
*/
if (inode->i_sb->s_magic != SOCKFS_MAGIC)
return -EOPNOTSUPP;
sock = SOCKET_I(inode);
if (sock == NULL || sock->sk == NULL)
return -EOPNOTSUPP;
ssp = sock->sk->sk_security;
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
ssp->smk_in = skp;
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
ssp->smk_out = skp;
if (sock->sk->sk_family == PF_INET) {
rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
if (rc != 0)
printk(KERN_WARNING
"Smack: \"%s\" netlbl error %d.\n",
__func__, -rc);
}
} else
return -EOPNOTSUPP;
#ifdef SMACK_IPV6_PORT_LABELING
if (sock->sk->sk_family == PF_INET6)
smk_ipv6_port_label(sock, NULL);
#endif
return 0;
}
/**
* smack_socket_post_create - finish socket setup
* @sock: the socket
* @family: protocol family
* @type: unused
* @protocol: unused
* @kern: unused
*
* Sets the netlabel information on the socket
*
* Returns 0 on success, and error code otherwise
*/
static int smack_socket_post_create(struct socket *sock, int family,
int type, int protocol, int kern)
{
struct socket_smack *ssp;
if (sock->sk == NULL)
return 0;
/*
* Sockets created by kernel threads receive web label.
*/
if (unlikely(current->flags & PF_KTHREAD)) {
ssp = sock->sk->sk_security;
ssp->smk_in = &smack_known_web;
ssp->smk_out = &smack_known_web;
}
if (family != PF_INET)
return 0;
/*
* Set the outbound netlbl.
*/
return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
}
#ifdef SMACK_IPV6_PORT_LABELING
/**
* smack_socket_bind - record port binding information.
* @sock: the socket
* @address: the port address
* @addrlen: size of the address
*
* Records the label bound to a port.
*
* Returns 0
*/
static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
int addrlen)
{
if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
smk_ipv6_port_label(sock, address);
return 0;
}
#endif /* SMACK_IPV6_PORT_LABELING */
/**
* smack_socket_connect - connect access check
* @sock: the socket
* @sap: the other end
* @addrlen: size of sap
*
* Verifies that a connection may be possible
*
* Returns 0 on success, and error code otherwise
*/
static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
int addrlen)
{
int rc = 0;
#if IS_ENABLED(CONFIG_IPV6)
struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
#endif
#ifdef SMACK_IPV6_SECMARK_LABELING
struct smack_known *rsp;
struct socket_smack *ssp = sock->sk->sk_security;
#endif
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;
#ifdef SMACK_IPV6_SECMARK_LABELING
rsp = smack_ipv6host_label(sip);
if (rsp != NULL)
rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
SMK_CONNECTING);
#endif
#ifdef SMACK_IPV6_PORT_LABELING
rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
#endif
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;