linux/security/smack/smack_lsm.c
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   1/*
   2 *  Simplified MAC Kernel (smack) security module
   3 *
   4 *  This file contains the smack hook function implementations.
   5 *
   6 *  Authors:
   7 *      Casey Schaufler <casey@schaufler-ca.com>
   8 *      Jarkko Sakkinen <jarkko.sakkinen@intel.com>
   9 *
  10 *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
  11 *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
  12 *                Paul Moore <paul@paul-moore.com>
  13 *  Copyright (C) 2010 Nokia Corporation
  14 *  Copyright (C) 2011 Intel Corporation.
  15 *
  16 *      This program is free software; you can redistribute it and/or modify
  17 *      it under the terms of the GNU General Public License version 2,
  18 *      as published by the Free Software Foundation.
  19 */
  20
  21#include <linux/xattr.h>
  22#include <linux/pagemap.h>
  23#include <linux/mount.h>
  24#include <linux/stat.h>
  25#include <linux/kd.h>
  26#include <asm/ioctls.h>
  27#include <linux/ip.h>
  28#include <linux/tcp.h>
  29#include <linux/udp.h>
  30#include <linux/slab.h>
  31#include <linux/mutex.h>
  32#include <linux/pipe_fs_i.h>
  33#include <net/cipso_ipv4.h>
  34#include <linux/audit.h>
  35#include <linux/magic.h>
  36#include <linux/dcache.h>
  37#include <linux/personality.h>
  38#include <linux/msg.h>
  39#include <linux/shm.h>
  40#include <linux/binfmts.h>
  41#include "smack.h"
  42
  43#define task_security(task)     (task_cred_xxx((task), security))
  44
  45#define TRANS_TRUE      "TRUE"
  46#define TRANS_TRUE_SIZE 4
  47
  48/**
  49 * smk_fetch - Fetch the smack label from a file.
  50 * @ip: a pointer to the inode
  51 * @dp: a pointer to the dentry
  52 *
  53 * Returns a pointer to the master list entry for the Smack label
  54 * or NULL if there was no label to fetch.
  55 */
  56static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
  57{
  58        int rc;
  59        char *buffer;
  60        char *result = NULL;
  61
  62        if (ip->i_op->getxattr == NULL)
  63                return NULL;
  64
  65        buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
  66        if (buffer == NULL)
  67                return NULL;
  68
  69        rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
  70        if (rc > 0)
  71                result = smk_import(buffer, rc);
  72
  73        kfree(buffer);
  74
  75        return result;
  76}
  77
  78/**
  79 * new_inode_smack - allocate an inode security blob
  80 * @smack: a pointer to the Smack label to use in the blob
  81 *
  82 * Returns the new blob or NULL if there's no memory available
  83 */
  84struct inode_smack *new_inode_smack(char *smack)
  85{
  86        struct inode_smack *isp;
  87
  88        isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS);
  89        if (isp == NULL)
  90                return NULL;
  91
  92        isp->smk_inode = smack;
  93        isp->smk_flags = 0;
  94        mutex_init(&isp->smk_lock);
  95
  96        return isp;
  97}
  98
  99/**
 100 * new_task_smack - allocate a task security blob
 101 * @smack: a pointer to the Smack label to use in the blob
 102 *
 103 * Returns the new blob or NULL if there's no memory available
 104 */
 105static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
 106{
 107        struct task_smack *tsp;
 108
 109        tsp = kzalloc(sizeof(struct task_smack), gfp);
 110        if (tsp == NULL)
 111                return NULL;
 112
 113        tsp->smk_task = task;
 114        tsp->smk_forked = forked;
 115        INIT_LIST_HEAD(&tsp->smk_rules);
 116        mutex_init(&tsp->smk_rules_lock);
 117
 118        return tsp;
 119}
 120
 121/**
 122 * smk_copy_rules - copy a rule set
 123 * @nhead - new rules header pointer
 124 * @ohead - old rules header pointer
 125 *
 126 * Returns 0 on success, -ENOMEM on error
 127 */
 128static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
 129                                gfp_t gfp)
 130{
 131        struct smack_rule *nrp;
 132        struct smack_rule *orp;
 133        int rc = 0;
 134
 135        INIT_LIST_HEAD(nhead);
 136
 137        list_for_each_entry_rcu(orp, ohead, list) {
 138                nrp = kzalloc(sizeof(struct smack_rule), gfp);
 139                if (nrp == NULL) {
 140                        rc = -ENOMEM;
 141                        break;
 142                }
 143                *nrp = *orp;
 144                list_add_rcu(&nrp->list, nhead);
 145        }
 146        return rc;
 147}
 148
 149/*
 150 * LSM hooks.
 151 * We he, that is fun!
 152 */
 153
 154/**
 155 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
 156 * @ctp: child task pointer
 157 * @mode: ptrace attachment mode
 158 *
 159 * Returns 0 if access is OK, an error code otherwise
 160 *
 161 * Do the capability checks, and require read and write.
 162 */
 163static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
 164{
 165        int rc;
 166        struct smk_audit_info ad;
 167        char *tsp;
 168
 169        rc = cap_ptrace_access_check(ctp, mode);
 170        if (rc != 0)
 171                return rc;
 172
 173        tsp = smk_of_task(task_security(ctp));
 174        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
 175        smk_ad_setfield_u_tsk(&ad, ctp);
 176
 177        rc = smk_curacc(tsp, MAY_READWRITE, &ad);
 178        return rc;
 179}
 180
 181/**
 182 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
 183 * @ptp: parent task pointer
 184 *
 185 * Returns 0 if access is OK, an error code otherwise
 186 *
 187 * Do the capability checks, and require read and write.
 188 */
 189static int smack_ptrace_traceme(struct task_struct *ptp)
 190{
 191        int rc;
 192        struct smk_audit_info ad;
 193        char *tsp;
 194
 195        rc = cap_ptrace_traceme(ptp);
 196        if (rc != 0)
 197                return rc;
 198
 199        tsp = smk_of_task(task_security(ptp));
 200        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
 201        smk_ad_setfield_u_tsk(&ad, ptp);
 202
 203        rc = smk_curacc(tsp, MAY_READWRITE, &ad);
 204        return rc;
 205}
 206
 207/**
 208 * smack_syslog - Smack approval on syslog
 209 * @type: message type
 210 *
 211 * Require that the task has the floor label
 212 *
 213 * Returns 0 on success, error code otherwise.
 214 */
 215static int smack_syslog(int typefrom_file)
 216{
 217        int rc = 0;
 218        char *sp = smk_of_current();
 219
 220        if (smack_privileged(CAP_MAC_OVERRIDE))
 221                return 0;
 222
 223         if (sp != smack_known_floor.smk_known)
 224                rc = -EACCES;
 225
 226        return rc;
 227}
 228
 229
 230/*
 231 * Superblock Hooks.
 232 */
 233
 234/**
 235 * smack_sb_alloc_security - allocate a superblock blob
 236 * @sb: the superblock getting the blob
 237 *
 238 * Returns 0 on success or -ENOMEM on error.
 239 */
 240static int smack_sb_alloc_security(struct super_block *sb)
 241{
 242        struct superblock_smack *sbsp;
 243
 244        sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
 245
 246        if (sbsp == NULL)
 247                return -ENOMEM;
 248
 249        sbsp->smk_root = smack_known_floor.smk_known;
 250        sbsp->smk_default = smack_known_floor.smk_known;
 251        sbsp->smk_floor = smack_known_floor.smk_known;
 252        sbsp->smk_hat = smack_known_hat.smk_known;
 253        sbsp->smk_initialized = 0;
 254
 255        sb->s_security = sbsp;
 256
 257        return 0;
 258}
 259
 260/**
 261 * smack_sb_free_security - free a superblock blob
 262 * @sb: the superblock getting the blob
 263 *
 264 */
 265static void smack_sb_free_security(struct super_block *sb)
 266{
 267        kfree(sb->s_security);
 268        sb->s_security = NULL;
 269}
 270
 271/**
 272 * smack_sb_copy_data - copy mount options data for processing
 273 * @orig: where to start
 274 * @smackopts: mount options string
 275 *
 276 * Returns 0 on success or -ENOMEM on error.
 277 *
 278 * Copy the Smack specific mount options out of the mount
 279 * options list.
 280 */
 281static int smack_sb_copy_data(char *orig, char *smackopts)
 282{
 283        char *cp, *commap, *otheropts, *dp;
 284
 285        otheropts = (char *)get_zeroed_page(GFP_KERNEL);
 286        if (otheropts == NULL)
 287                return -ENOMEM;
 288
 289        for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
 290                if (strstr(cp, SMK_FSDEFAULT) == cp)
 291                        dp = smackopts;
 292                else if (strstr(cp, SMK_FSFLOOR) == cp)
 293                        dp = smackopts;
 294                else if (strstr(cp, SMK_FSHAT) == cp)
 295                        dp = smackopts;
 296                else if (strstr(cp, SMK_FSROOT) == cp)
 297                        dp = smackopts;
 298                else
 299                        dp = otheropts;
 300
 301                commap = strchr(cp, ',');
 302                if (commap != NULL)
 303                        *commap = '\0';
 304
 305                if (*dp != '\0')
 306                        strcat(dp, ",");
 307                strcat(dp, cp);
 308        }
 309
 310        strcpy(orig, otheropts);
 311        free_page((unsigned long)otheropts);
 312
 313        return 0;
 314}
 315
 316/**
 317 * smack_sb_kern_mount - Smack specific mount processing
 318 * @sb: the file system superblock
 319 * @flags: the mount flags
 320 * @data: the smack mount options
 321 *
 322 * Returns 0 on success, an error code on failure
 323 */
 324static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
 325{
 326        struct dentry *root = sb->s_root;
 327        struct inode *inode = root->d_inode;
 328        struct superblock_smack *sp = sb->s_security;
 329        struct inode_smack *isp;
 330        char *op;
 331        char *commap;
 332        char *nsp;
 333
 334        if (sp->smk_initialized != 0)
 335                return 0;
 336
 337        sp->smk_initialized = 1;
 338
 339        for (op = data; op != NULL; op = commap) {
 340                commap = strchr(op, ',');
 341                if (commap != NULL)
 342                        *commap++ = '\0';
 343
 344                if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
 345                        op += strlen(SMK_FSHAT);
 346                        nsp = smk_import(op, 0);
 347                        if (nsp != NULL)
 348                                sp->smk_hat = nsp;
 349                } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
 350                        op += strlen(SMK_FSFLOOR);
 351                        nsp = smk_import(op, 0);
 352                        if (nsp != NULL)
 353                                sp->smk_floor = nsp;
 354                } else if (strncmp(op, SMK_FSDEFAULT,
 355                                   strlen(SMK_FSDEFAULT)) == 0) {
 356                        op += strlen(SMK_FSDEFAULT);
 357                        nsp = smk_import(op, 0);
 358                        if (nsp != NULL)
 359                                sp->smk_default = nsp;
 360                } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
 361                        op += strlen(SMK_FSROOT);
 362                        nsp = smk_import(op, 0);
 363                        if (nsp != NULL)
 364                                sp->smk_root = nsp;
 365                }
 366        }
 367
 368        /*
 369         * Initialize the root inode.
 370         */
 371        isp = inode->i_security;
 372        if (isp == NULL)
 373                inode->i_security = new_inode_smack(sp->smk_root);
 374        else
 375                isp->smk_inode = sp->smk_root;
 376
 377        return 0;
 378}
 379
 380/**
 381 * smack_sb_statfs - Smack check on statfs
 382 * @dentry: identifies the file system in question
 383 *
 384 * Returns 0 if current can read the floor of the filesystem,
 385 * and error code otherwise
 386 */
 387static int smack_sb_statfs(struct dentry *dentry)
 388{
 389        struct superblock_smack *sbp = dentry->d_sb->s_security;
 390        int rc;
 391        struct smk_audit_info ad;
 392
 393        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 394        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 395
 396        rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
 397        return rc;
 398}
 399
 400/**
 401 * smack_sb_mount - Smack check for mounting
 402 * @dev_name: unused
 403 * @path: mount point
 404 * @type: unused
 405 * @flags: unused
 406 * @data: unused
 407 *
 408 * Returns 0 if current can write the floor of the filesystem
 409 * being mounted on, an error code otherwise.
 410 */
 411static int smack_sb_mount(const char *dev_name, struct path *path,
 412                          const char *type, unsigned long flags, void *data)
 413{
 414        struct superblock_smack *sbp = path->dentry->d_sb->s_security;
 415        struct smk_audit_info ad;
 416
 417        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 418        smk_ad_setfield_u_fs_path(&ad, *path);
 419
 420        return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
 421}
 422
 423/**
 424 * smack_sb_umount - Smack check for unmounting
 425 * @mnt: file system to unmount
 426 * @flags: unused
 427 *
 428 * Returns 0 if current can write the floor of the filesystem
 429 * being unmounted, an error code otherwise.
 430 */
 431static int smack_sb_umount(struct vfsmount *mnt, int flags)
 432{
 433        struct superblock_smack *sbp;
 434        struct smk_audit_info ad;
 435        struct path path;
 436
 437        path.dentry = mnt->mnt_root;
 438        path.mnt = mnt;
 439
 440        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 441        smk_ad_setfield_u_fs_path(&ad, path);
 442
 443        sbp = path.dentry->d_sb->s_security;
 444        return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
 445}
 446
 447/*
 448 * BPRM hooks
 449 */
 450
 451/**
 452 * smack_bprm_set_creds - set creds for exec
 453 * @bprm: the exec information
 454 *
 455 * Returns 0 if it gets a blob, -ENOMEM otherwise
 456 */
 457static int smack_bprm_set_creds(struct linux_binprm *bprm)
 458{
 459        struct inode *inode = bprm->file->f_path.dentry->d_inode;
 460        struct task_smack *bsp = bprm->cred->security;
 461        struct inode_smack *isp;
 462        int rc;
 463
 464        rc = cap_bprm_set_creds(bprm);
 465        if (rc != 0)
 466                return rc;
 467
 468        if (bprm->cred_prepared)
 469                return 0;
 470
 471        isp = inode->i_security;
 472        if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
 473                return 0;
 474
 475        if (bprm->unsafe)
 476                return -EPERM;
 477
 478        bsp->smk_task = isp->smk_task;
 479        bprm->per_clear |= PER_CLEAR_ON_SETID;
 480
 481        return 0;
 482}
 483
 484/**
 485 * smack_bprm_committing_creds - Prepare to install the new credentials
 486 * from bprm.
 487 *
 488 * @bprm: binprm for exec
 489 */
 490static void smack_bprm_committing_creds(struct linux_binprm *bprm)
 491{
 492        struct task_smack *bsp = bprm->cred->security;
 493
 494        if (bsp->smk_task != bsp->smk_forked)
 495                current->pdeath_signal = 0;
 496}
 497
 498/**
 499 * smack_bprm_secureexec - Return the decision to use secureexec.
 500 * @bprm: binprm for exec
 501 *
 502 * Returns 0 on success.
 503 */
 504static int smack_bprm_secureexec(struct linux_binprm *bprm)
 505{
 506        struct task_smack *tsp = current_security();
 507        int ret = cap_bprm_secureexec(bprm);
 508
 509        if (!ret && (tsp->smk_task != tsp->smk_forked))
 510                ret = 1;
 511
 512        return ret;
 513}
 514
 515/*
 516 * Inode hooks
 517 */
 518
 519/**
 520 * smack_inode_alloc_security - allocate an inode blob
 521 * @inode: the inode in need of a blob
 522 *
 523 * Returns 0 if it gets a blob, -ENOMEM otherwise
 524 */
 525static int smack_inode_alloc_security(struct inode *inode)
 526{
 527        inode->i_security = new_inode_smack(smk_of_current());
 528        if (inode->i_security == NULL)
 529                return -ENOMEM;
 530        return 0;
 531}
 532
 533/**
 534 * smack_inode_free_security - free an inode blob
 535 * @inode: the inode with a blob
 536 *
 537 * Clears the blob pointer in inode
 538 */
 539static void smack_inode_free_security(struct inode *inode)
 540{
 541        kfree(inode->i_security);
 542        inode->i_security = NULL;
 543}
 544
 545/**
 546 * smack_inode_init_security - copy out the smack from an inode
 547 * @inode: the inode
 548 * @dir: unused
 549 * @qstr: unused
 550 * @name: where to put the attribute name
 551 * @value: where to put the attribute value
 552 * @len: where to put the length of the attribute
 553 *
 554 * Returns 0 if it all works out, -ENOMEM if there's no memory
 555 */
 556static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 557                                     const struct qstr *qstr, char **name,
 558                                     void **value, size_t *len)
 559{
 560        struct smack_known *skp;
 561        struct inode_smack *issp = inode->i_security;
 562        char *csp = smk_of_current();
 563        char *isp = smk_of_inode(inode);
 564        char *dsp = smk_of_inode(dir);
 565        int may;
 566
 567        if (name) {
 568                *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_NOFS);
 569                if (*name == NULL)
 570                        return -ENOMEM;
 571        }
 572
 573        if (value) {
 574                skp = smk_find_entry(csp);
 575                rcu_read_lock();
 576                may = smk_access_entry(csp, dsp, &skp->smk_rules);
 577                rcu_read_unlock();
 578
 579                /*
 580                 * If the access rule allows transmutation and
 581                 * the directory requests transmutation then
 582                 * by all means transmute.
 583                 * Mark the inode as changed.
 584                 */
 585                if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
 586                    smk_inode_transmutable(dir)) {
 587                        isp = dsp;
 588                        issp->smk_flags |= SMK_INODE_CHANGED;
 589                }
 590
 591                *value = kstrdup(isp, GFP_NOFS);
 592                if (*value == NULL)
 593                        return -ENOMEM;
 594        }
 595
 596        if (len)
 597                *len = strlen(isp) + 1;
 598
 599        return 0;
 600}
 601
 602/**
 603 * smack_inode_link - Smack check on link
 604 * @old_dentry: the existing object
 605 * @dir: unused
 606 * @new_dentry: the new object
 607 *
 608 * Returns 0 if access is permitted, an error code otherwise
 609 */
 610static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
 611                            struct dentry *new_dentry)
 612{
 613        char *isp;
 614        struct smk_audit_info ad;
 615        int rc;
 616
 617        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 618        smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
 619
 620        isp = smk_of_inode(old_dentry->d_inode);
 621        rc = smk_curacc(isp, MAY_WRITE, &ad);
 622
 623        if (rc == 0 && new_dentry->d_inode != NULL) {
 624                isp = smk_of_inode(new_dentry->d_inode);
 625                smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
 626                rc = smk_curacc(isp, MAY_WRITE, &ad);
 627        }
 628
 629        return rc;
 630}
 631
 632/**
 633 * smack_inode_unlink - Smack check on inode deletion
 634 * @dir: containing directory object
 635 * @dentry: file to unlink
 636 *
 637 * Returns 0 if current can write the containing directory
 638 * and the object, error code otherwise
 639 */
 640static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
 641{
 642        struct inode *ip = dentry->d_inode;
 643        struct smk_audit_info ad;
 644        int rc;
 645
 646        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 647        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 648
 649        /*
 650         * You need write access to the thing you're unlinking
 651         */
 652        rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
 653        if (rc == 0) {
 654                /*
 655                 * You also need write access to the containing directory
 656                 */
 657                smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
 658                smk_ad_setfield_u_fs_inode(&ad, dir);
 659                rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
 660        }
 661        return rc;
 662}
 663
 664/**
 665 * smack_inode_rmdir - Smack check on directory deletion
 666 * @dir: containing directory object
 667 * @dentry: directory to unlink
 668 *
 669 * Returns 0 if current can write the containing directory
 670 * and the directory, error code otherwise
 671 */
 672static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
 673{
 674        struct smk_audit_info ad;
 675        int rc;
 676
 677        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 678        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 679
 680        /*
 681         * You need write access to the thing you're removing
 682         */
 683        rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
 684        if (rc == 0) {
 685                /*
 686                 * You also need write access to the containing directory
 687                 */
 688                smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
 689                smk_ad_setfield_u_fs_inode(&ad, dir);
 690                rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
 691        }
 692
 693        return rc;
 694}
 695
 696/**
 697 * smack_inode_rename - Smack check on rename
 698 * @old_inode: the old directory
 699 * @old_dentry: unused
 700 * @new_inode: the new directory
 701 * @new_dentry: unused
 702 *
 703 * Read and write access is required on both the old and
 704 * new directories.
 705 *
 706 * Returns 0 if access is permitted, an error code otherwise
 707 */
 708static int smack_inode_rename(struct inode *old_inode,
 709                              struct dentry *old_dentry,
 710                              struct inode *new_inode,
 711                              struct dentry *new_dentry)
 712{
 713        int rc;
 714        char *isp;
 715        struct smk_audit_info ad;
 716
 717        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 718        smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
 719
 720        isp = smk_of_inode(old_dentry->d_inode);
 721        rc = smk_curacc(isp, MAY_READWRITE, &ad);
 722
 723        if (rc == 0 && new_dentry->d_inode != NULL) {
 724                isp = smk_of_inode(new_dentry->d_inode);
 725                smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
 726                rc = smk_curacc(isp, MAY_READWRITE, &ad);
 727        }
 728        return rc;
 729}
 730
 731/**
 732 * smack_inode_permission - Smack version of permission()
 733 * @inode: the inode in question
 734 * @mask: the access requested
 735 *
 736 * This is the important Smack hook.
 737 *
 738 * Returns 0 if access is permitted, -EACCES otherwise
 739 */
 740static int smack_inode_permission(struct inode *inode, int mask)
 741{
 742        struct smk_audit_info ad;
 743        int no_block = mask & MAY_NOT_BLOCK;
 744
 745        mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
 746        /*
 747         * No permission to check. Existence test. Yup, it's there.
 748         */
 749        if (mask == 0)
 750                return 0;
 751
 752        /* May be droppable after audit */
 753        if (no_block)
 754                return -ECHILD;
 755        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
 756        smk_ad_setfield_u_fs_inode(&ad, inode);
 757        return smk_curacc(smk_of_inode(inode), mask, &ad);
 758}
 759
 760/**
 761 * smack_inode_setattr - Smack check for setting attributes
 762 * @dentry: the object
 763 * @iattr: for the force flag
 764 *
 765 * Returns 0 if access is permitted, an error code otherwise
 766 */
 767static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
 768{
 769        struct smk_audit_info ad;
 770        /*
 771         * Need to allow for clearing the setuid bit.
 772         */
 773        if (iattr->ia_valid & ATTR_FORCE)
 774                return 0;
 775        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 776        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 777
 778        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
 779}
 780
 781/**
 782 * smack_inode_getattr - Smack check for getting attributes
 783 * @mnt: unused
 784 * @dentry: the object
 785 *
 786 * Returns 0 if access is permitted, an error code otherwise
 787 */
 788static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 789{
 790        struct smk_audit_info ad;
 791        struct path path;
 792
 793        path.dentry = dentry;
 794        path.mnt = mnt;
 795
 796        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 797        smk_ad_setfield_u_fs_path(&ad, path);
 798        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
 799}
 800
 801/**
 802 * smack_inode_setxattr - Smack check for setting xattrs
 803 * @dentry: the object
 804 * @name: name of the attribute
 805 * @value: unused
 806 * @size: unused
 807 * @flags: unused
 808 *
 809 * This protects the Smack attribute explicitly.
 810 *
 811 * Returns 0 if access is permitted, an error code otherwise
 812 */
 813static int smack_inode_setxattr(struct dentry *dentry, const char *name,
 814                                const void *value, size_t size, int flags)
 815{
 816        struct smk_audit_info ad;
 817        int rc = 0;
 818
 819        if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
 820            strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
 821            strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
 822            strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
 823            strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
 824                if (!smack_privileged(CAP_MAC_ADMIN))
 825                        rc = -EPERM;
 826                /*
 827                 * check label validity here so import wont fail on
 828                 * post_setxattr
 829                 */
 830                if (size == 0 || size >= SMK_LONGLABEL ||
 831                    smk_import(value, size) == NULL)
 832                        rc = -EINVAL;
 833        } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
 834                if (!smack_privileged(CAP_MAC_ADMIN))
 835                        rc = -EPERM;
 836                if (size != TRANS_TRUE_SIZE ||
 837                    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
 838                        rc = -EINVAL;
 839        } else
 840                rc = cap_inode_setxattr(dentry, name, value, size, flags);
 841
 842        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 843        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 844
 845        if (rc == 0)
 846                rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
 847
 848        return rc;
 849}
 850
 851/**
 852 * smack_inode_post_setxattr - Apply the Smack update approved above
 853 * @dentry: object
 854 * @name: attribute name
 855 * @value: attribute value
 856 * @size: attribute size
 857 * @flags: unused
 858 *
 859 * Set the pointer in the inode blob to the entry found
 860 * in the master label list.
 861 */
 862static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
 863                                      const void *value, size_t size, int flags)
 864{
 865        char *nsp;
 866        struct inode_smack *isp = dentry->d_inode->i_security;
 867
 868        if (strcmp(name, XATTR_NAME_SMACK) == 0) {
 869                nsp = smk_import(value, size);
 870                if (nsp != NULL)
 871                        isp->smk_inode = nsp;
 872                else
 873                        isp->smk_inode = smack_known_invalid.smk_known;
 874        } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
 875                nsp = smk_import(value, size);
 876                if (nsp != NULL)
 877                        isp->smk_task = nsp;
 878                else
 879                        isp->smk_task = smack_known_invalid.smk_known;
 880        } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
 881                nsp = smk_import(value, size);
 882                if (nsp != NULL)
 883                        isp->smk_mmap = nsp;
 884                else
 885                        isp->smk_mmap = smack_known_invalid.smk_known;
 886        } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
 887                isp->smk_flags |= SMK_INODE_TRANSMUTE;
 888
 889        return;
 890}
 891
 892/**
 893 * smack_inode_getxattr - Smack check on getxattr
 894 * @dentry: the object
 895 * @name: unused
 896 *
 897 * Returns 0 if access is permitted, an error code otherwise
 898 */
 899static int smack_inode_getxattr(struct dentry *dentry, const char *name)
 900{
 901        struct smk_audit_info ad;
 902
 903        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 904        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 905
 906        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
 907}
 908
 909/**
 910 * smack_inode_removexattr - Smack check on removexattr
 911 * @dentry: the object
 912 * @name: name of the attribute
 913 *
 914 * Removing the Smack attribute requires CAP_MAC_ADMIN
 915 *
 916 * Returns 0 if access is permitted, an error code otherwise
 917 */
 918static int smack_inode_removexattr(struct dentry *dentry, const char *name)
 919{
 920        struct inode_smack *isp;
 921        struct smk_audit_info ad;
 922        int rc = 0;
 923
 924        if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
 925            strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
 926            strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
 927            strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
 928            strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
 929            strcmp(name, XATTR_NAME_SMACKMMAP)) {
 930                if (!smack_privileged(CAP_MAC_ADMIN))
 931                        rc = -EPERM;
 932        } else
 933                rc = cap_inode_removexattr(dentry, name);
 934
 935        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 936        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 937        if (rc == 0)
 938                rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
 939
 940        if (rc == 0) {
 941                isp = dentry->d_inode->i_security;
 942                isp->smk_task = NULL;
 943                isp->smk_mmap = NULL;
 944        }
 945
 946        return rc;
 947}
 948
 949/**
 950 * smack_inode_getsecurity - get smack xattrs
 951 * @inode: the object
 952 * @name: attribute name
 953 * @buffer: where to put the result
 954 * @alloc: unused
 955 *
 956 * Returns the size of the attribute or an error code
 957 */
 958static int smack_inode_getsecurity(const struct inode *inode,
 959                                   const char *name, void **buffer,
 960                                   bool alloc)
 961{
 962        struct socket_smack *ssp;
 963        struct socket *sock;
 964        struct super_block *sbp;
 965        struct inode *ip = (struct inode *)inode;
 966        char *isp;
 967        int ilen;
 968        int rc = 0;
 969
 970        if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
 971                isp = smk_of_inode(inode);
 972                ilen = strlen(isp) + 1;
 973                *buffer = isp;
 974                return ilen;
 975        }
 976
 977        /*
 978         * The rest of the Smack xattrs are only on sockets.
 979         */
 980        sbp = ip->i_sb;
 981        if (sbp->s_magic != SOCKFS_MAGIC)
 982                return -EOPNOTSUPP;
 983
 984        sock = SOCKET_I(ip);
 985        if (sock == NULL || sock->sk == NULL)
 986                return -EOPNOTSUPP;
 987
 988        ssp = sock->sk->sk_security;
 989
 990        if (strcmp(name, XATTR_SMACK_IPIN) == 0)
 991                isp = ssp->smk_in;
 992        else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
 993                isp = ssp->smk_out;
 994        else
 995                return -EOPNOTSUPP;
 996
 997        ilen = strlen(isp) + 1;
 998        if (rc == 0) {
 999                *buffer = isp;
1000                rc = ilen;
1001        }
1002
1003        return rc;
1004}
1005
1006
1007/**
1008 * smack_inode_listsecurity - list the Smack attributes
1009 * @inode: the object
1010 * @buffer: where they go
1011 * @buffer_size: size of buffer
1012 *
1013 * Returns 0 on success, -EINVAL otherwise
1014 */
1015static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1016                                    size_t buffer_size)
1017{
1018        int len = strlen(XATTR_NAME_SMACK);
1019
1020        if (buffer != NULL && len <= buffer_size) {
1021                memcpy(buffer, XATTR_NAME_SMACK, len);
1022                return len;
1023        }
1024        return -EINVAL;
1025}
1026
1027/**
1028 * smack_inode_getsecid - Extract inode's security id
1029 * @inode: inode to extract the info from
1030 * @secid: where result will be saved
1031 */
1032static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
1033{
1034        struct inode_smack *isp = inode->i_security;
1035
1036        *secid = smack_to_secid(isp->smk_inode);
1037}
1038
1039/*
1040 * File Hooks
1041 */
1042
1043/**
1044 * smack_file_permission - Smack check on file operations
1045 * @file: unused
1046 * @mask: unused
1047 *
1048 * Returns 0
1049 *
1050 * Should access checks be done on each read or write?
1051 * UNICOS and SELinux say yes.
1052 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1053 *
1054 * I'll say no for now. Smack does not do the frequent
1055 * label changing that SELinux does.
1056 */
1057static int smack_file_permission(struct file *file, int mask)
1058{
1059        return 0;
1060}
1061
1062/**
1063 * smack_file_alloc_security - assign a file security blob
1064 * @file: the object
1065 *
1066 * The security blob for a file is a pointer to the master
1067 * label list, so no allocation is done.
1068 *
1069 * Returns 0
1070 */
1071static int smack_file_alloc_security(struct file *file)
1072{
1073        file->f_security = smk_of_current();
1074        return 0;
1075}
1076
1077/**
1078 * smack_file_free_security - clear a file security blob
1079 * @file: the object
1080 *
1081 * The security blob for a file is a pointer to the master
1082 * label list, so no memory is freed.
1083 */
1084static void smack_file_free_security(struct file *file)
1085{
1086        file->f_security = NULL;
1087}
1088
1089/**
1090 * smack_file_ioctl - Smack check on ioctls
1091 * @file: the object
1092 * @cmd: what to do
1093 * @arg: unused
1094 *
1095 * Relies heavily on the correct use of the ioctl command conventions.
1096 *
1097 * Returns 0 if allowed, error code otherwise
1098 */
1099static int smack_file_ioctl(struct file *file, unsigned int cmd,
1100                            unsigned long arg)
1101{
1102        int rc = 0;
1103        struct smk_audit_info ad;
1104
1105        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1106        smk_ad_setfield_u_fs_path(&ad, file->f_path);
1107
1108        if (_IOC_DIR(cmd) & _IOC_WRITE)
1109                rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1110
1111        if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1112                rc = smk_curacc(file->f_security, MAY_READ, &ad);
1113
1114        return rc;
1115}
1116
1117/**
1118 * smack_file_lock - Smack check on file locking
1119 * @file: the object
1120 * @cmd: unused
1121 *
1122 * Returns 0 if current has write access, error code otherwise
1123 */
1124static int smack_file_lock(struct file *file, unsigned int cmd)
1125{
1126        struct smk_audit_info ad;
1127
1128        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1129        smk_ad_setfield_u_fs_path(&ad, file->f_path);
1130        return smk_curacc(file->f_security, MAY_WRITE, &ad);
1131}
1132
1133/**
1134 * smack_file_fcntl - Smack check on fcntl
1135 * @file: the object
1136 * @cmd: what action to check
1137 * @arg: unused
1138 *
1139 * Generally these operations are harmless.
1140 * File locking operations present an obvious mechanism
1141 * for passing information, so they require write access.
1142 *
1143 * Returns 0 if current has access, error code otherwise
1144 */
1145static int smack_file_fcntl(struct file *file, unsigned int cmd,
1146                            unsigned long arg)
1147{
1148        struct smk_audit_info ad;
1149        int rc = 0;
1150
1151
1152        switch (cmd) {
1153        case F_GETLK:
1154        case F_SETLK:
1155        case F_SETLKW:
1156        case F_SETOWN:
1157        case F_SETSIG:
1158                smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1159                smk_ad_setfield_u_fs_path(&ad, file->f_path);
1160                rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1161                break;
1162        default:
1163                break;
1164        }
1165
1166        return rc;
1167}
1168
1169/**
1170 * smack_mmap_file :
1171 * Check permissions for a mmap operation.  The @file may be NULL, e.g.
1172 * if mapping anonymous memory.
1173 * @file contains the file structure for file to map (may be NULL).
1174 * @reqprot contains the protection requested by the application.
1175 * @prot contains the protection that will be applied by the kernel.
1176 * @flags contains the operational flags.
1177 * Return 0 if permission is granted.
1178 */
1179static int smack_mmap_file(struct file *file,
1180                           unsigned long reqprot, unsigned long prot,
1181                           unsigned long flags)
1182{
1183        struct smack_known *skp;
1184        struct smack_rule *srp;
1185        struct task_smack *tsp;
1186        char *sp;
1187        char *msmack;
1188        char *osmack;
1189        struct inode_smack *isp;
1190        struct dentry *dp;
1191        int may;
1192        int mmay;
1193        int tmay;
1194        int rc;
1195
1196        if (file == NULL || file->f_dentry == NULL)
1197                return 0;
1198
1199        dp = file->f_dentry;
1200
1201        if (dp->d_inode == NULL)
1202                return 0;
1203
1204        isp = dp->d_inode->i_security;
1205        if (isp->smk_mmap == NULL)
1206                return 0;
1207        msmack = isp->smk_mmap;
1208
1209        tsp = current_security();
1210        sp = smk_of_current();
1211        skp = smk_find_entry(sp);
1212        rc = 0;
1213
1214        rcu_read_lock();
1215        /*
1216         * For each Smack rule associated with the subject
1217         * label verify that the SMACK64MMAP also has access
1218         * to that rule's object label.
1219         */
1220        list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1221                osmack = srp->smk_object;
1222                /*
1223                 * Matching labels always allows access.
1224                 */
1225                if (msmack == osmack)
1226                        continue;
1227                /*
1228                 * If there is a matching local rule take
1229                 * that into account as well.
1230                 */
1231                may = smk_access_entry(srp->smk_subject, osmack,
1232                                        &tsp->smk_rules);
1233                if (may == -ENOENT)
1234                        may = srp->smk_access;
1235                else
1236                        may &= srp->smk_access;
1237                /*
1238                 * If may is zero the SMACK64MMAP subject can't
1239                 * possibly have less access.
1240                 */
1241                if (may == 0)
1242                        continue;
1243
1244                /*
1245                 * Fetch the global list entry.
1246                 * If there isn't one a SMACK64MMAP subject
1247                 * can't have as much access as current.
1248                 */
1249                skp = smk_find_entry(msmack);
1250                mmay = smk_access_entry(msmack, osmack, &skp->smk_rules);
1251                if (mmay == -ENOENT) {
1252                        rc = -EACCES;
1253                        break;
1254                }
1255                /*
1256                 * If there is a local entry it modifies the
1257                 * potential access, too.
1258                 */
1259                tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules);
1260                if (tmay != -ENOENT)
1261                        mmay &= tmay;
1262
1263                /*
1264                 * If there is any access available to current that is
1265                 * not available to a SMACK64MMAP subject
1266                 * deny access.
1267                 */
1268                if ((may | mmay) != mmay) {
1269                        rc = -EACCES;
1270                        break;
1271                }
1272        }
1273
1274        rcu_read_unlock();
1275
1276        return rc;
1277}
1278
1279/**
1280 * smack_file_set_fowner - set the file security blob value
1281 * @file: object in question
1282 *
1283 * Returns 0
1284 * Further research may be required on this one.
1285 */
1286static int smack_file_set_fowner(struct file *file)
1287{
1288        file->f_security = smk_of_current();
1289        return 0;
1290}
1291
1292/**
1293 * smack_file_send_sigiotask - Smack on sigio
1294 * @tsk: The target task
1295 * @fown: the object the signal come from
1296 * @signum: unused
1297 *
1298 * Allow a privileged task to get signals even if it shouldn't
1299 *
1300 * Returns 0 if a subject with the object's smack could
1301 * write to the task, an error code otherwise.
1302 */
1303static int smack_file_send_sigiotask(struct task_struct *tsk,
1304                                     struct fown_struct *fown, int signum)
1305{
1306        struct file *file;
1307        int rc;
1308        char *tsp = smk_of_task(tsk->cred->security);
1309        struct smk_audit_info ad;
1310
1311        /*
1312         * struct fown_struct is never outside the context of a struct file
1313         */
1314        file = container_of(fown, struct file, f_owner);
1315
1316        /* we don't log here as rc can be overriden */
1317        rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1318        if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1319                rc = 0;
1320
1321        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1322        smk_ad_setfield_u_tsk(&ad, tsk);
1323        smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1324        return rc;
1325}
1326
1327/**
1328 * smack_file_receive - Smack file receive check
1329 * @file: the object
1330 *
1331 * Returns 0 if current has access, error code otherwise
1332 */
1333static int smack_file_receive(struct file *file)
1334{
1335        int may = 0;
1336        struct smk_audit_info ad;
1337
1338        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1339        smk_ad_setfield_u_fs_path(&ad, file->f_path);
1340        /*
1341         * This code relies on bitmasks.
1342         */
1343        if (file->f_mode & FMODE_READ)
1344                may = MAY_READ;
1345        if (file->f_mode & FMODE_WRITE)
1346                may |= MAY_WRITE;
1347
1348        return smk_curacc(file->f_security, may, &ad);
1349}
1350
1351/**
1352 * smack_file_open - Smack dentry open processing
1353 * @file: the object
1354 * @cred: unused
1355 *
1356 * Set the security blob in the file structure.
1357 *
1358 * Returns 0
1359 */
1360static int smack_file_open(struct file *file, const struct cred *cred)
1361{
1362        struct inode_smack *isp = file->f_path.dentry->d_inode->i_security;
1363
1364        file->f_security = isp->smk_inode;
1365
1366        return 0;
1367}
1368
1369/*
1370 * Task hooks
1371 */
1372
1373/**
1374 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1375 * @new: the new credentials
1376 * @gfp: the atomicity of any memory allocations
1377 *
1378 * Prepare a blank set of credentials for modification.  This must allocate all
1379 * the memory the LSM module might require such that cred_transfer() can
1380 * complete without error.
1381 */
1382static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1383{
1384        struct task_smack *tsp;
1385
1386        tsp = new_task_smack(NULL, NULL, gfp);
1387        if (tsp == NULL)
1388                return -ENOMEM;
1389
1390        cred->security = tsp;
1391
1392        return 0;
1393}
1394
1395
1396/**
1397 * smack_cred_free - "free" task-level security credentials
1398 * @cred: the credentials in question
1399 *
1400 */
1401static void smack_cred_free(struct cred *cred)
1402{
1403        struct task_smack *tsp = cred->security;
1404        struct smack_rule *rp;
1405        struct list_head *l;
1406        struct list_head *n;
1407
1408        if (tsp == NULL)
1409                return;
1410        cred->security = NULL;
1411
1412        list_for_each_safe(l, n, &tsp->smk_rules) {
1413                rp = list_entry(l, struct smack_rule, list);
1414                list_del(&rp->list);
1415                kfree(rp);
1416        }
1417        kfree(tsp);
1418}
1419
1420/**
1421 * smack_cred_prepare - prepare new set of credentials for modification
1422 * @new: the new credentials
1423 * @old: the original credentials
1424 * @gfp: the atomicity of any memory allocations
1425 *
1426 * Prepare a new set of credentials for modification.
1427 */
1428static int smack_cred_prepare(struct cred *new, const struct cred *old,
1429                              gfp_t gfp)
1430{
1431        struct task_smack *old_tsp = old->security;
1432        struct task_smack *new_tsp;
1433        int rc;
1434
1435        new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1436        if (new_tsp == NULL)
1437                return -ENOMEM;
1438
1439        rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1440        if (rc != 0)
1441                return rc;
1442
1443        new->security = new_tsp;
1444        return 0;
1445}
1446
1447/**
1448 * smack_cred_transfer - Transfer the old credentials to the new credentials
1449 * @new: the new credentials
1450 * @old: the original credentials
1451 *
1452 * Fill in a set of blank credentials from another set of credentials.
1453 */
1454static void smack_cred_transfer(struct cred *new, const struct cred *old)
1455{
1456        struct task_smack *old_tsp = old->security;
1457        struct task_smack *new_tsp = new->security;
1458
1459        new_tsp->smk_task = old_tsp->smk_task;
1460        new_tsp->smk_forked = old_tsp->smk_task;
1461        mutex_init(&new_tsp->smk_rules_lock);
1462        INIT_LIST_HEAD(&new_tsp->smk_rules);
1463
1464
1465        /* cbs copy rule list */
1466}
1467
1468/**
1469 * smack_kernel_act_as - Set the subjective context in a set of credentials
1470 * @new: points to the set of credentials to be modified.
1471 * @secid: specifies the security ID to be set
1472 *
1473 * Set the security data for a kernel service.
1474 */
1475static int smack_kernel_act_as(struct cred *new, u32 secid)
1476{
1477        struct task_smack *new_tsp = new->security;
1478        char *smack = smack_from_secid(secid);
1479
1480        if (smack == NULL)
1481                return -EINVAL;
1482
1483        new_tsp->smk_task = smack;
1484        return 0;
1485}
1486
1487/**
1488 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1489 * @new: points to the set of credentials to be modified
1490 * @inode: points to the inode to use as a reference
1491 *
1492 * Set the file creation context in a set of credentials to the same
1493 * as the objective context of the specified inode
1494 */
1495static int smack_kernel_create_files_as(struct cred *new,
1496                                        struct inode *inode)
1497{
1498        struct inode_smack *isp = inode->i_security;
1499        struct task_smack *tsp = new->security;
1500
1501        tsp->smk_forked = isp->smk_inode;
1502        tsp->smk_task = isp->smk_inode;
1503        return 0;
1504}
1505
1506/**
1507 * smk_curacc_on_task - helper to log task related access
1508 * @p: the task object
1509 * @access: the access requested
1510 * @caller: name of the calling function for audit
1511 *
1512 * Return 0 if access is permitted
1513 */
1514static int smk_curacc_on_task(struct task_struct *p, int access,
1515                                const char *caller)
1516{
1517        struct smk_audit_info ad;
1518
1519        smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
1520        smk_ad_setfield_u_tsk(&ad, p);
1521        return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1522}
1523
1524/**
1525 * smack_task_setpgid - Smack check on setting pgid
1526 * @p: the task object
1527 * @pgid: unused
1528 *
1529 * Return 0 if write access is permitted
1530 */
1531static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1532{
1533        return smk_curacc_on_task(p, MAY_WRITE, __func__);
1534}
1535
1536/**
1537 * smack_task_getpgid - Smack access check for getpgid
1538 * @p: the object task
1539 *
1540 * Returns 0 if current can read the object task, error code otherwise
1541 */
1542static int smack_task_getpgid(struct task_struct *p)
1543{
1544        return smk_curacc_on_task(p, MAY_READ, __func__);
1545}
1546
1547/**
1548 * smack_task_getsid - Smack access check for getsid
1549 * @p: the object task
1550 *
1551 * Returns 0 if current can read the object task, error code otherwise
1552 */
1553static int smack_task_getsid(struct task_struct *p)
1554{
1555        return smk_curacc_on_task(p, MAY_READ, __func__);
1556}
1557
1558/**
1559 * smack_task_getsecid - get the secid of the task
1560 * @p: the object task
1561 * @secid: where to put the result
1562 *
1563 * Sets the secid to contain a u32 version of the smack label.
1564 */
1565static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1566{
1567        *secid = smack_to_secid(smk_of_task(task_security(p)));
1568}
1569
1570/**
1571 * smack_task_setnice - Smack check on setting nice
1572 * @p: the task object
1573 * @nice: unused
1574 *
1575 * Return 0 if write access is permitted
1576 */
1577static int smack_task_setnice(struct task_struct *p, int nice)
1578{
1579        int rc;
1580
1581        rc = cap_task_setnice(p, nice);
1582        if (rc == 0)
1583                rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1584        return rc;
1585}
1586
1587/**
1588 * smack_task_setioprio - Smack check on setting ioprio
1589 * @p: the task object
1590 * @ioprio: unused
1591 *
1592 * Return 0 if write access is permitted
1593 */
1594static int smack_task_setioprio(struct task_struct *p, int ioprio)
1595{
1596        int rc;
1597
1598        rc = cap_task_setioprio(p, ioprio);
1599        if (rc == 0)
1600                rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1601        return rc;
1602}
1603
1604/**
1605 * smack_task_getioprio - Smack check on reading ioprio
1606 * @p: the task object
1607 *
1608 * Return 0 if read access is permitted
1609 */
1610static int smack_task_getioprio(struct task_struct *p)
1611{
1612        return smk_curacc_on_task(p, MAY_READ, __func__);
1613}
1614
1615/**
1616 * smack_task_setscheduler - Smack check on setting scheduler
1617 * @p: the task object
1618 * @policy: unused
1619 * @lp: unused
1620 *
1621 * Return 0 if read access is permitted
1622 */
1623static int smack_task_setscheduler(struct task_struct *p)
1624{
1625        int rc;
1626
1627        rc = cap_task_setscheduler(p);
1628        if (rc == 0)
1629                rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1630        return rc;
1631}
1632
1633/**
1634 * smack_task_getscheduler - Smack check on reading scheduler
1635 * @p: the task object
1636 *
1637 * Return 0 if read access is permitted
1638 */
1639static int smack_task_getscheduler(struct task_struct *p)
1640{
1641        return smk_curacc_on_task(p, MAY_READ, __func__);
1642}
1643
1644/**
1645 * smack_task_movememory - Smack check on moving memory
1646 * @p: the task object
1647 *
1648 * Return 0 if write access is permitted
1649 */
1650static int smack_task_movememory(struct task_struct *p)
1651{
1652        return smk_curacc_on_task(p, MAY_WRITE, __func__);
1653}
1654
1655/**
1656 * smack_task_kill - Smack check on signal delivery
1657 * @p: the task object
1658 * @info: unused
1659 * @sig: unused
1660 * @secid: identifies the smack to use in lieu of current's
1661 *
1662 * Return 0 if write access is permitted
1663 *
1664 * The secid behavior is an artifact of an SELinux hack
1665 * in the USB code. Someday it may go away.
1666 */
1667static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1668                           int sig, u32 secid)
1669{
1670        struct smk_audit_info ad;
1671
1672        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1673        smk_ad_setfield_u_tsk(&ad, p);
1674        /*
1675         * Sending a signal requires that the sender
1676         * can write the receiver.
1677         */
1678        if (secid == 0)
1679                return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1680                                  &ad);
1681        /*
1682         * If the secid isn't 0 we're dealing with some USB IO
1683         * specific behavior. This is not clean. For one thing
1684         * we can't take privilege into account.
1685         */
1686        return smk_access(smack_from_secid(secid),
1687                          smk_of_task(task_security(p)), MAY_WRITE, &ad);
1688}
1689
1690/**
1691 * smack_task_wait - Smack access check for waiting
1692 * @p: task to wait for
1693 *
1694 * Returns 0
1695 */
1696static int smack_task_wait(struct task_struct *p)
1697{
1698        /*
1699         * Allow the operation to succeed.
1700         * Zombies are bad.
1701         * In userless environments (e.g. phones) programs
1702         * get marked with SMACK64EXEC and even if the parent
1703         * and child shouldn't be talking the parent still
1704         * may expect to know when the child exits.
1705         */
1706        return 0;
1707}
1708
1709/**
1710 * smack_task_to_inode - copy task smack into the inode blob
1711 * @p: task to copy from
1712 * @inode: inode to copy to
1713 *
1714 * Sets the smack pointer in the inode security blob
1715 */
1716static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1717{
1718        struct inode_smack *isp = inode->i_security;
1719        isp->smk_inode = smk_of_task(task_security(p));
1720}
1721
1722/*
1723 * Socket hooks.
1724 */
1725
1726/**
1727 * smack_sk_alloc_security - Allocate a socket blob
1728 * @sk: the socket
1729 * @family: unused
1730 * @gfp_flags: memory allocation flags
1731 *
1732 * Assign Smack pointers to current
1733 *
1734 * Returns 0 on success, -ENOMEM is there's no memory
1735 */
1736static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1737{
1738        char *csp = smk_of_current();
1739        struct socket_smack *ssp;
1740
1741        ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1742        if (ssp == NULL)
1743                return -ENOMEM;
1744
1745        ssp->smk_in = csp;
1746        ssp->smk_out = csp;
1747        ssp->smk_packet = NULL;
1748
1749        sk->sk_security = ssp;
1750
1751        return 0;
1752}
1753
1754/**
1755 * smack_sk_free_security - Free a socket blob
1756 * @sk: the socket
1757 *
1758 * Clears the blob pointer
1759 */
1760static void smack_sk_free_security(struct sock *sk)
1761{
1762        kfree(sk->sk_security);
1763}
1764
1765/**
1766* smack_host_label - check host based restrictions
1767* @sip: the object end
1768*
1769* looks for host based access restrictions
1770*
1771* This version will only be appropriate for really small sets of single label
1772* hosts.  The caller is responsible for ensuring that the RCU read lock is
1773* taken before calling this function.
1774*
1775* Returns the label of the far end or NULL if it's not special.
1776*/
1777static char *smack_host_label(struct sockaddr_in *sip)
1778{
1779        struct smk_netlbladdr *snp;
1780        struct in_addr *siap = &sip->sin_addr;
1781
1782        if (siap->s_addr == 0)
1783                return NULL;
1784
1785        list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1786                /*
1787                * we break after finding the first match because
1788                * the list is sorted from longest to shortest mask
1789                * so we have found the most specific match
1790                */
1791                if ((&snp->smk_host.sin_addr)->s_addr ==
1792                    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1793                        /* we have found the special CIPSO option */
1794                        if (snp->smk_label == smack_cipso_option)
1795                                return NULL;
1796                        return snp->smk_label;
1797                }
1798
1799        return NULL;
1800}
1801
1802/**
1803 * smack_netlabel - Set the secattr on a socket
1804 * @sk: the socket
1805 * @labeled: socket label scheme
1806 *
1807 * Convert the outbound smack value (smk_out) to a
1808 * secattr and attach it to the socket.
1809 *
1810 * Returns 0 on success or an error code
1811 */
1812static int smack_netlabel(struct sock *sk, int labeled)
1813{
1814        struct smack_known *skp;
1815        struct socket_smack *ssp = sk->sk_security;
1816        int rc = 0;
1817
1818        /*
1819         * Usually the netlabel code will handle changing the
1820         * packet labeling based on the label.
1821         * The case of a single label host is different, because
1822         * a single label host should never get a labeled packet
1823         * even though the label is usually associated with a packet
1824         * label.
1825         */
1826        local_bh_disable();
1827        bh_lock_sock_nested(sk);
1828
1829        if (ssp->smk_out == smack_net_ambient ||
1830            labeled == SMACK_UNLABELED_SOCKET)
1831                netlbl_sock_delattr(sk);
1832        else {
1833                skp = smk_find_entry(ssp->smk_out);
1834                rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
1835        }
1836
1837        bh_unlock_sock(sk);
1838        local_bh_enable();
1839
1840        return rc;
1841}
1842
1843/**
1844 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1845 * @sk: the socket
1846 * @sap: the destination address
1847 *
1848 * Set the correct secattr for the given socket based on the destination
1849 * address and perform any outbound access checks needed.
1850 *
1851 * Returns 0 on success or an error code.
1852 *
1853 */
1854static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1855{
1856        int rc;
1857        int sk_lbl;
1858        char *hostsp;
1859        struct socket_smack *ssp = sk->sk_security;
1860        struct smk_audit_info ad;
1861
1862        rcu_read_lock();
1863        hostsp = smack_host_label(sap);
1864        if (hostsp != NULL) {
1865#ifdef CONFIG_AUDIT
1866                struct lsm_network_audit net;
1867
1868                smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
1869                ad.a.u.net->family = sap->sin_family;
1870                ad.a.u.net->dport = sap->sin_port;
1871                ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
1872#endif
1873                sk_lbl = SMACK_UNLABELED_SOCKET;
1874                rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1875        } else {
1876                sk_lbl = SMACK_CIPSO_SOCKET;
1877                rc = 0;
1878        }
1879        rcu_read_unlock();
1880        if (rc != 0)
1881                return rc;
1882
1883        return smack_netlabel(sk, sk_lbl);
1884}
1885
1886/**
1887 * smack_inode_setsecurity - set smack xattrs
1888 * @inode: the object
1889 * @name: attribute name
1890 * @value: attribute value
1891 * @size: size of the attribute
1892 * @flags: unused
1893 *
1894 * Sets the named attribute in the appropriate blob
1895 *
1896 * Returns 0 on success, or an error code
1897 */
1898static int smack_inode_setsecurity(struct inode *inode, const char *name,
1899                                   const void *value, size_t size, int flags)
1900{
1901        char *sp;
1902        struct inode_smack *nsp = inode->i_security;
1903        struct socket_smack *ssp;
1904        struct socket *sock;
1905        int rc = 0;
1906
1907        if (value == NULL || size > SMK_LONGLABEL || size == 0)
1908                return -EACCES;
1909
1910        sp = smk_import(value, size);
1911        if (sp == NULL)
1912                return -EINVAL;
1913
1914        if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1915                nsp->smk_inode = sp;
1916                nsp->smk_flags |= SMK_INODE_INSTANT;
1917                return 0;
1918        }
1919        /*
1920         * The rest of the Smack xattrs are only on sockets.
1921         */
1922        if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1923                return -EOPNOTSUPP;
1924
1925        sock = SOCKET_I(inode);
1926        if (sock == NULL || sock->sk == NULL)
1927                return -EOPNOTSUPP;
1928
1929        ssp = sock->sk->sk_security;
1930
1931        if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1932                ssp->smk_in = sp;
1933        else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1934                ssp->smk_out = sp;
1935                if (sock->sk->sk_family != PF_UNIX) {
1936                        rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1937                        if (rc != 0)
1938                                printk(KERN_WARNING
1939                                        "Smack: \"%s\" netlbl error %d.\n",
1940                                        __func__, -rc);
1941                }
1942        } else
1943                return -EOPNOTSUPP;
1944
1945        return 0;
1946}
1947
1948/**
1949 * smack_socket_post_create - finish socket setup
1950 * @sock: the socket
1951 * @family: protocol family
1952 * @type: unused
1953 * @protocol: unused
1954 * @kern: unused
1955 *
1956 * Sets the netlabel information on the socket
1957 *
1958 * Returns 0 on success, and error code otherwise
1959 */
1960static int smack_socket_post_create(struct socket *sock, int family,
1961                                    int type, int protocol, int kern)
1962{
1963        if (family != PF_INET || sock->sk == NULL)
1964                return 0;
1965        /*
1966         * Set the outbound netlbl.
1967         */
1968        return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1969}
1970
1971/**
1972 * smack_socket_connect - connect access check
1973 * @sock: the socket
1974 * @sap: the other end
1975 * @addrlen: size of sap
1976 *
1977 * Verifies that a connection may be possible
1978 *
1979 * Returns 0 on success, and error code otherwise
1980 */
1981static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
1982                                int addrlen)
1983{
1984        if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
1985                return 0;
1986        if (addrlen < sizeof(struct sockaddr_in))
1987                return -EINVAL;
1988
1989        return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
1990}
1991
1992/**
1993 * smack_flags_to_may - convert S_ to MAY_ values
1994 * @flags: the S_ value
1995 *
1996 * Returns the equivalent MAY_ value
1997 */
1998static int smack_flags_to_may(int flags)
1999{
2000        int may = 0;
2001
2002        if (flags & S_IRUGO)
2003                may |= MAY_READ;
2004        if (flags & S_IWUGO)
2005                may |= MAY_WRITE;
2006        if (flags & S_IXUGO)
2007                may |= MAY_EXEC;
2008
2009        return may;
2010}
2011
2012/**
2013 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2014 * @msg: the object
2015 *
2016 * Returns 0
2017 */
2018static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2019{
2020        msg->security = smk_of_current();
2021        return 0;
2022}
2023
2024/**
2025 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2026 * @msg: the object
2027 *
2028 * Clears the blob pointer
2029 */
2030static void smack_msg_msg_free_security(struct msg_msg *msg)
2031{
2032        msg->security = NULL;
2033}
2034
2035/**
2036 * smack_of_shm - the smack pointer for the shm
2037 * @shp: the object
2038 *
2039 * Returns a pointer to the smack value
2040 */
2041static char *smack_of_shm(struct shmid_kernel *shp)
2042{
2043        return (char *)shp->shm_perm.security;
2044}
2045
2046/**
2047 * smack_shm_alloc_security - Set the security blob for shm
2048 * @shp: the object
2049 *
2050 * Returns 0
2051 */
2052static int smack_shm_alloc_security(struct shmid_kernel *shp)
2053{
2054        struct kern_ipc_perm *isp = &shp->shm_perm;
2055
2056        isp->security = smk_of_current();
2057        return 0;
2058}
2059
2060/**
2061 * smack_shm_free_security - Clear the security blob for shm
2062 * @shp: the object
2063 *
2064 * Clears the blob pointer
2065 */
2066static void smack_shm_free_security(struct shmid_kernel *shp)
2067{
2068        struct kern_ipc_perm *isp = &shp->shm_perm;
2069
2070        isp->security = NULL;
2071}
2072
2073/**
2074 * smk_curacc_shm : check if current has access on shm
2075 * @shp : the object
2076 * @access : access requested
2077 *
2078 * Returns 0 if current has the requested access, error code otherwise
2079 */
2080static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2081{
2082        char *ssp = smack_of_shm(shp);
2083        struct smk_audit_info ad;
2084
2085#ifdef CONFIG_AUDIT
2086        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2087        ad.a.u.ipc_id = shp->shm_perm.id;
2088#endif
2089        return smk_curacc(ssp, access, &ad);
2090}
2091
2092/**
2093 * smack_shm_associate - Smack access check for shm
2094 * @shp: the object
2095 * @shmflg: access requested
2096 *
2097 * Returns 0 if current has the requested access, error code otherwise
2098 */
2099static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2100{
2101        int may;
2102
2103        may = smack_flags_to_may(shmflg);
2104        return smk_curacc_shm(shp, may);
2105}
2106
2107/**
2108 * smack_shm_shmctl - Smack access check for shm
2109 * @shp: the object
2110 * @cmd: what it wants to do
2111 *
2112 * Returns 0 if current has the requested access, error code otherwise
2113 */
2114static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2115{
2116        int may;
2117
2118        switch (cmd) {
2119        case IPC_STAT:
2120        case SHM_STAT:
2121                may = MAY_READ;
2122                break;
2123        case IPC_SET:
2124        case SHM_LOCK:
2125        case SHM_UNLOCK:
2126        case IPC_RMID:
2127                may = MAY_READWRITE;
2128                break;
2129        case IPC_INFO:
2130        case SHM_INFO:
2131                /*
2132                 * System level information.
2133                 */
2134                return 0;
2135        default:
2136                return -EINVAL;
2137        }
2138        return smk_curacc_shm(shp, may);
2139}
2140
2141/**
2142 * smack_shm_shmat - Smack access for shmat
2143 * @shp: the object
2144 * @shmaddr: unused
2145 * @shmflg: access requested
2146 *
2147 * Returns 0 if current has the requested access, error code otherwise
2148 */
2149static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2150                           int shmflg)
2151{
2152        int may;
2153
2154        may = smack_flags_to_may(shmflg);
2155        return smk_curacc_shm(shp, may);
2156}
2157
2158/**
2159 * smack_of_sem - the smack pointer for the sem
2160 * @sma: the object
2161 *
2162 * Returns a pointer to the smack value
2163 */
2164static char *smack_of_sem(struct sem_array *sma)
2165{
2166        return (char *)sma->sem_perm.security;
2167}
2168
2169/**
2170 * smack_sem_alloc_security - Set the security blob for sem
2171 * @sma: the object
2172 *
2173 * Returns 0
2174 */
2175static int smack_sem_alloc_security(struct sem_array *sma)
2176{
2177        struct kern_ipc_perm *isp = &sma->sem_perm;
2178
2179        isp->security = smk_of_current();
2180        return 0;
2181}
2182
2183/**
2184 * smack_sem_free_security - Clear the security blob for sem
2185 * @sma: the object
2186 *
2187 * Clears the blob pointer
2188 */
2189static void smack_sem_free_security(struct sem_array *sma)
2190{
2191        struct kern_ipc_perm *isp = &sma->sem_perm;
2192
2193        isp->security = NULL;
2194}
2195
2196/**
2197 * smk_curacc_sem : check if current has access on sem
2198 * @sma : the object
2199 * @access : access requested
2200 *
2201 * Returns 0 if current has the requested access, error code otherwise
2202 */
2203static int smk_curacc_sem(struct sem_array *sma, int access)
2204{
2205        char *ssp = smack_of_sem(sma);
2206        struct smk_audit_info ad;
2207
2208#ifdef CONFIG_AUDIT
2209        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2210        ad.a.u.ipc_id = sma->sem_perm.id;
2211#endif
2212        return smk_curacc(ssp, access, &ad);
2213}
2214
2215/**
2216 * smack_sem_associate - Smack access check for sem
2217 * @sma: the object
2218 * @semflg: access requested
2219 *
2220 * Returns 0 if current has the requested access, error code otherwise
2221 */
2222static int smack_sem_associate(struct sem_array *sma, int semflg)
2223{
2224        int may;
2225
2226        may = smack_flags_to_may(semflg);
2227        return smk_curacc_sem(sma, may);
2228}
2229
2230/**
2231 * smack_sem_shmctl - Smack access check for sem
2232 * @sma: the object
2233 * @cmd: what it wants to do
2234 *
2235 * Returns 0 if current has the requested access, error code otherwise
2236 */
2237static int smack_sem_semctl(struct sem_array *sma, int cmd)
2238{
2239        int may;
2240
2241        switch (cmd) {
2242        case GETPID:
2243        case GETNCNT:
2244        case GETZCNT:
2245        case GETVAL:
2246        case GETALL:
2247        case IPC_STAT:
2248        case SEM_STAT:
2249                may = MAY_READ;
2250                break;
2251        case SETVAL:
2252        case SETALL:
2253        case IPC_RMID:
2254        case IPC_SET:
2255                may = MAY_READWRITE;
2256                break;
2257        case IPC_INFO:
2258        case SEM_INFO:
2259                /*
2260                 * System level information
2261                 */
2262                return 0;
2263        default:
2264                return -EINVAL;
2265        }
2266
2267        return smk_curacc_sem(sma, may);
2268}
2269
2270/**
2271 * smack_sem_semop - Smack checks of semaphore operations
2272 * @sma: the object
2273 * @sops: unused
2274 * @nsops: unused
2275 * @alter: unused
2276 *
2277 * Treated as read and write in all cases.
2278 *
2279 * Returns 0 if access is allowed, error code otherwise
2280 */
2281static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2282                           unsigned nsops, int alter)
2283{
2284        return smk_curacc_sem(sma, MAY_READWRITE);
2285}
2286
2287/**
2288 * smack_msg_alloc_security - Set the security blob for msg
2289 * @msq: the object
2290 *
2291 * Returns 0
2292 */
2293static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2294{
2295        struct kern_ipc_perm *kisp = &msq->q_perm;
2296
2297        kisp->security = smk_of_current();
2298        return 0;
2299}
2300
2301/**
2302 * smack_msg_free_security - Clear the security blob for msg
2303 * @msq: the object
2304 *
2305 * Clears the blob pointer
2306 */
2307static void smack_msg_queue_free_security(struct msg_queue *msq)
2308{
2309        struct kern_ipc_perm *kisp = &msq->q_perm;
2310
2311        kisp->security = NULL;
2312}
2313
2314/**
2315 * smack_of_msq - the smack pointer for the msq
2316 * @msq: the object
2317 *
2318 * Returns a pointer to the smack value
2319 */
2320static char *smack_of_msq(struct msg_queue *msq)
2321{
2322        return (char *)msq->q_perm.security;
2323}
2324
2325/**
2326 * smk_curacc_msq : helper to check if current has access on msq
2327 * @msq : the msq
2328 * @access : access requested
2329 *
2330 * return 0 if current has access, error otherwise
2331 */
2332static int smk_curacc_msq(struct msg_queue *msq, int access)
2333{
2334        char *msp = smack_of_msq(msq);
2335        struct smk_audit_info ad;
2336
2337#ifdef CONFIG_AUDIT
2338        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2339        ad.a.u.ipc_id = msq->q_perm.id;
2340#endif
2341        return smk_curacc(msp, access, &ad);
2342}
2343
2344/**
2345 * smack_msg_queue_associate - Smack access check for msg_queue
2346 * @msq: the object
2347 * @msqflg: access requested
2348 *
2349 * Returns 0 if current has the requested access, error code otherwise
2350 */
2351static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2352{
2353        int may;
2354
2355        may = smack_flags_to_may(msqflg);
2356        return smk_curacc_msq(msq, may);
2357}
2358
2359/**
2360 * smack_msg_queue_msgctl - Smack access check for msg_queue
2361 * @msq: the object
2362 * @cmd: what it wants to do
2363 *
2364 * Returns 0 if current has the requested access, error code otherwise
2365 */
2366static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2367{
2368        int may;
2369
2370        switch (cmd) {
2371        case IPC_STAT:
2372        case MSG_STAT:
2373                may = MAY_READ;
2374                break;
2375        case IPC_SET:
2376        case IPC_RMID:
2377                may = MAY_READWRITE;
2378                break;
2379        case IPC_INFO:
2380        case MSG_INFO:
2381                /*
2382                 * System level information
2383                 */
2384                return 0;
2385        default:
2386                return -EINVAL;
2387        }
2388
2389        return smk_curacc_msq(msq, may);
2390}
2391
2392/**
2393 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2394 * @msq: the object
2395 * @msg: unused
2396 * @msqflg: access requested
2397 *
2398 * Returns 0 if current has the requested access, error code otherwise
2399 */
2400static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2401                                  int msqflg)
2402{
2403        int may;
2404
2405        may = smack_flags_to_may(msqflg);
2406        return smk_curacc_msq(msq, may);
2407}
2408
2409/**
2410 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2411 * @msq: the object
2412 * @msg: unused
2413 * @target: unused
2414 * @type: unused
2415 * @mode: unused
2416 *
2417 * Returns 0 if current has read and write access, error code otherwise
2418 */
2419static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2420                        struct task_struct *target, long type, int mode)
2421{
2422        return smk_curacc_msq(msq, MAY_READWRITE);
2423}
2424
2425/**
2426 * smack_ipc_permission - Smack access for ipc_permission()
2427 * @ipp: the object permissions
2428 * @flag: access requested
2429 *
2430 * Returns 0 if current has read and write access, error code otherwise
2431 */
2432static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2433{
2434        char *isp = ipp->security;
2435        int may = smack_flags_to_may(flag);
2436        struct smk_audit_info ad;
2437
2438#ifdef CONFIG_AUDIT
2439        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2440        ad.a.u.ipc_id = ipp->id;
2441#endif
2442        return smk_curacc(isp, may, &ad);
2443}
2444
2445/**
2446 * smack_ipc_getsecid - Extract smack security id
2447 * @ipp: the object permissions
2448 * @secid: where result will be saved
2449 */
2450static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2451{
2452        char *smack = ipp->security;
2453
2454        *secid = smack_to_secid(smack);
2455}
2456
2457/**
2458 * smack_d_instantiate - Make sure the blob is correct on an inode
2459 * @opt_dentry: dentry where inode will be attached
2460 * @inode: the object
2461 *
2462 * Set the inode's security blob if it hasn't been done already.
2463 */
2464static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2465{
2466        struct super_block *sbp;
2467        struct superblock_smack *sbsp;
2468        struct inode_smack *isp;
2469        char *csp = smk_of_current();
2470        char *fetched;
2471        char *final;
2472        char trattr[TRANS_TRUE_SIZE];
2473        int transflag = 0;
2474        int rc;
2475        struct dentry *dp;
2476
2477        if (inode == NULL)
2478                return;
2479
2480        isp = inode->i_security;
2481
2482        mutex_lock(&isp->smk_lock);
2483        /*
2484         * If the inode is already instantiated
2485         * take the quick way out
2486         */
2487        if (isp->smk_flags & SMK_INODE_INSTANT)
2488                goto unlockandout;
2489
2490        sbp = inode->i_sb;
2491        sbsp = sbp->s_security;
2492        /*
2493         * We're going to use the superblock default label
2494         * if there's no label on the file.
2495         */
2496        final = sbsp->smk_default;
2497
2498        /*
2499         * If this is the root inode the superblock
2500         * may be in the process of initialization.
2501         * If that is the case use the root value out
2502         * of the superblock.
2503         */
2504        if (opt_dentry->d_parent == opt_dentry) {
2505                isp->smk_inode = sbsp->smk_root;
2506                isp->smk_flags |= SMK_INODE_INSTANT;
2507                goto unlockandout;
2508        }
2509
2510        /*
2511         * This is pretty hackish.
2512         * Casey says that we shouldn't have to do
2513         * file system specific code, but it does help
2514         * with keeping it simple.
2515         */
2516        switch (sbp->s_magic) {
2517        case SMACK_MAGIC:
2518                /*
2519                 * Casey says that it's a little embarrassing
2520                 * that the smack file system doesn't do
2521                 * extended attributes.
2522                 */
2523                final = smack_known_star.smk_known;
2524                break;
2525        case PIPEFS_MAGIC:
2526                /*
2527                 * Casey says pipes are easy (?)
2528                 */
2529                final = smack_known_star.smk_known;
2530                break;
2531        case DEVPTS_SUPER_MAGIC:
2532                /*
2533                 * devpts seems content with the label of the task.
2534                 * Programs that change smack have to treat the
2535                 * pty with respect.
2536                 */
2537                final = csp;
2538                break;
2539        case SOCKFS_MAGIC:
2540                /*
2541                 * Socket access is controlled by the socket
2542                 * structures associated with the task involved.
2543                 */
2544                final = smack_known_star.smk_known;
2545                break;
2546        case PROC_SUPER_MAGIC:
2547                /*
2548                 * Casey says procfs appears not to care.
2549                 * The superblock default suffices.
2550                 */
2551                break;
2552        case TMPFS_MAGIC:
2553                /*
2554                 * Device labels should come from the filesystem,
2555                 * but watch out, because they're volitile,
2556                 * getting recreated on every reboot.
2557                 */
2558                final = smack_known_star.smk_known;
2559                /*
2560                 * No break.
2561                 *
2562                 * If a smack value has been set we want to use it,
2563                 * but since tmpfs isn't giving us the opportunity
2564                 * to set mount options simulate setting the
2565                 * superblock default.
2566                 */
2567        default:
2568                /*
2569                 * This isn't an understood special case.
2570                 * Get the value from the xattr.
2571                 */
2572
2573                /*
2574                 * UNIX domain sockets use lower level socket data.
2575                 */
2576                if (S_ISSOCK(inode->i_mode)) {
2577                        final = smack_known_star.smk_known;
2578                        break;
2579                }
2580                /*
2581                 * No xattr support means, alas, no SMACK label.
2582                 * Use the aforeapplied default.
2583                 * It would be curious if the label of the task
2584                 * does not match that assigned.
2585                 */
2586                if (inode->i_op->getxattr == NULL)
2587                        break;
2588                /*
2589                 * Get the dentry for xattr.
2590                 */
2591                dp = dget(opt_dentry);
2592                fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2593                if (fetched != NULL)
2594                        final = fetched;
2595
2596                /*
2597                 * Transmuting directory
2598                 */
2599                if (S_ISDIR(inode->i_mode)) {
2600                        /*
2601                         * If this is a new directory and the label was
2602                         * transmuted when the inode was initialized
2603                         * set the transmute attribute on the directory
2604                         * and mark the inode.
2605                         *
2606                         * If there is a transmute attribute on the
2607                         * directory mark the inode.
2608                         */
2609                        if (isp->smk_flags & SMK_INODE_CHANGED) {
2610                                isp->smk_flags &= ~SMK_INODE_CHANGED;
2611                                rc = inode->i_op->setxattr(dp,
2612                                        XATTR_NAME_SMACKTRANSMUTE,
2613                                        TRANS_TRUE, TRANS_TRUE_SIZE,
2614                                        0);
2615                        } else {
2616                                rc = inode->i_op->getxattr(dp,
2617                                        XATTR_NAME_SMACKTRANSMUTE, trattr,
2618                                        TRANS_TRUE_SIZE);
2619                                if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
2620                                                       TRANS_TRUE_SIZE) != 0)
2621                                        rc = -EINVAL;
2622                        }
2623                        if (rc >= 0)
2624                                transflag = SMK_INODE_TRANSMUTE;
2625                }
2626                isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2627                isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2628
2629                dput(dp);
2630                break;
2631        }
2632
2633        if (final == NULL)
2634                isp->smk_inode = csp;
2635        else
2636                isp->smk_inode = final;
2637
2638        isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2639
2640unlockandout:
2641        mutex_unlock(&isp->smk_lock);
2642        return;
2643}
2644
2645/**
2646 * smack_getprocattr - Smack process attribute access
2647 * @p: the object task
2648 * @name: the name of the attribute in /proc/.../attr
2649 * @value: where to put the result
2650 *
2651 * Places a copy of the task Smack into value
2652 *
2653 * Returns the length of the smack label or an error code
2654 */
2655static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2656{
2657        char *cp;
2658        int slen;
2659
2660        if (strcmp(name, "current") != 0)
2661                return -EINVAL;
2662
2663        cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2664        if (cp == NULL)
2665                return -ENOMEM;
2666
2667        slen = strlen(cp);
2668        *value = cp;
2669        return slen;
2670}
2671
2672/**
2673 * smack_setprocattr - Smack process attribute setting
2674 * @p: the object task
2675 * @name: the name of the attribute in /proc/.../attr
2676 * @value: the value to set
2677 * @size: the size of the value
2678 *
2679 * Sets the Smack value of the task. Only setting self
2680 * is permitted and only with privilege
2681 *
2682 * Returns the length of the smack label or an error code
2683 */
2684static int smack_setprocattr(struct task_struct *p, char *name,
2685                             void *value, size_t size)
2686{
2687        struct task_smack *tsp;
2688        struct cred *new;
2689        char *newsmack;
2690
2691        /*
2692         * Changing another process' Smack value is too dangerous
2693         * and supports no sane use case.
2694         */
2695        if (p != current)
2696                return -EPERM;
2697
2698        if (!smack_privileged(CAP_MAC_ADMIN))
2699                return -EPERM;
2700
2701        if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
2702                return -EINVAL;
2703
2704        if (strcmp(name, "current") != 0)
2705                return -EINVAL;
2706
2707        newsmack = smk_import(value, size);
2708        if (newsmack == NULL)
2709                return -EINVAL;
2710
2711        /*
2712         * No process is ever allowed the web ("@") label.
2713         */
2714        if (newsmack == smack_known_web.smk_known)
2715                return -EPERM;
2716
2717        new = prepare_creds();
2718        if (new == NULL)
2719                return -ENOMEM;
2720
2721        tsp = new->security;
2722        tsp->smk_task = newsmack;
2723
2724        commit_creds(new);
2725        return size;
2726}
2727
2728/**
2729 * smack_unix_stream_connect - Smack access on UDS
2730 * @sock: one sock
2731 * @other: the other sock
2732 * @newsk: unused
2733 *
2734 * Return 0 if a subject with the smack of sock could access
2735 * an object with the smack of other, otherwise an error code
2736 */
2737static int smack_unix_stream_connect(struct sock *sock,
2738                                     struct sock *other, struct sock *newsk)
2739{
2740        struct socket_smack *ssp = sock->sk_security;
2741        struct socket_smack *osp = other->sk_security;
2742        struct socket_smack *nsp = newsk->sk_security;
2743        struct smk_audit_info ad;
2744        int rc = 0;
2745
2746#ifdef CONFIG_AUDIT
2747        struct lsm_network_audit net;
2748
2749        smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2750        smk_ad_setfield_u_net_sk(&ad, other);
2751#endif
2752
2753        if (!smack_privileged(CAP_MAC_OVERRIDE))
2754                rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2755
2756        /*
2757         * Cross reference the peer labels for SO_PEERSEC.
2758         */
2759        if (rc == 0) {
2760                nsp->smk_packet = ssp->smk_out;
2761                ssp->smk_packet = osp->smk_out;
2762        }
2763
2764        return rc;
2765}
2766
2767/**
2768 * smack_unix_may_send - Smack access on UDS
2769 * @sock: one socket
2770 * @other: the other socket
2771 *
2772 * Return 0 if a subject with the smack of sock could access
2773 * an object with the smack of other, otherwise an error code
2774 */
2775static int smack_unix_may_send(struct socket *sock, struct socket *other)
2776{
2777        struct socket_smack *ssp = sock->sk->sk_security;
2778        struct socket_smack *osp = other->sk->sk_security;
2779        struct smk_audit_info ad;
2780        int rc = 0;
2781
2782#ifdef CONFIG_AUDIT
2783        struct lsm_network_audit net;
2784
2785        smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2786        smk_ad_setfield_u_net_sk(&ad, other->sk);
2787#endif
2788
2789        if (!smack_privileged(CAP_MAC_OVERRIDE))
2790                rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2791
2792        return rc;
2793}
2794
2795/**
2796 * smack_socket_sendmsg - Smack check based on destination host
2797 * @sock: the socket
2798 * @msg: the message
2799 * @size: the size of the message
2800 *
2801 * Return 0 if the current subject can write to the destination
2802 * host. This is only a question if the destination is a single
2803 * label host.
2804 */
2805static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2806                                int size)
2807{
2808        struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2809
2810        /*
2811         * Perfectly reasonable for this to be NULL
2812         */
2813        if (sip == NULL || sip->sin_family != AF_INET)
2814                return 0;
2815
2816        return smack_netlabel_send(sock->sk, sip);
2817}
2818
2819/**
2820 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2821 * @sap: netlabel secattr
2822 * @ssp: socket security information
2823 *
2824 * Returns a pointer to a Smack label found on the label list.
2825 */
2826static char *smack_from_secattr(struct netlbl_lsm_secattr *sap,
2827                                struct socket_smack *ssp)
2828{
2829        struct smack_known *kp;
2830        char *sp;
2831        int found = 0;
2832
2833        if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2834                /*
2835                 * Looks like a CIPSO packet.
2836                 * If there are flags but no level netlabel isn't
2837                 * behaving the way we expect it to.
2838                 *
2839                 * Look it up in the label table
2840                 * Without guidance regarding the smack value
2841                 * for the packet fall back on the network
2842                 * ambient value.
2843                 */
2844                rcu_read_lock();
2845                list_for_each_entry(kp, &smack_known_list, list) {
2846                        if (sap->attr.mls.lvl != kp->smk_netlabel.attr.mls.lvl)
2847                                continue;
2848                        if (memcmp(sap->attr.mls.cat,
2849                                kp->smk_netlabel.attr.mls.cat,
2850                                SMK_CIPSOLEN) != 0)
2851                                continue;
2852                        found = 1;
2853                        break;
2854                }
2855                rcu_read_unlock();
2856
2857                if (found)
2858                        return kp->smk_known;
2859
2860                if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
2861                        return smack_known_web.smk_known;
2862                return smack_known_star.smk_known;
2863        }
2864        if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2865                /*
2866                 * Looks like a fallback, which gives us a secid.
2867                 */
2868                sp = smack_from_secid(sap->attr.secid);
2869                /*
2870                 * This has got to be a bug because it is
2871                 * impossible to specify a fallback without
2872                 * specifying the label, which will ensure
2873                 * it has a secid, and the only way to get a
2874                 * secid is from a fallback.
2875                 */
2876                BUG_ON(sp == NULL);
2877                return sp;
2878        }
2879        /*
2880         * Without guidance regarding the smack value
2881         * for the packet fall back on the network
2882         * ambient value.
2883         */
2884        return smack_net_ambient;
2885}
2886
2887/**
2888 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2889 * @sk: socket
2890 * @skb: packet
2891 *
2892 * Returns 0 if the packet should be delivered, an error code otherwise
2893 */
2894static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2895{
2896        struct netlbl_lsm_secattr secattr;
2897        struct socket_smack *ssp = sk->sk_security;
2898        char *csp;
2899        int rc;
2900        struct smk_audit_info ad;
2901#ifdef CONFIG_AUDIT
2902        struct lsm_network_audit net;
2903#endif
2904        if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2905                return 0;
2906
2907        /*
2908         * Translate what netlabel gave us.
2909         */
2910        netlbl_secattr_init(&secattr);
2911
2912        rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2913        if (rc == 0)
2914                csp = smack_from_secattr(&secattr, ssp);
2915        else
2916                csp = smack_net_ambient;
2917
2918        netlbl_secattr_destroy(&secattr);
2919
2920#ifdef CONFIG_AUDIT
2921        smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2922        ad.a.u.net->family = sk->sk_family;
2923        ad.a.u.net->netif = skb->skb_iif;
2924        ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2925#endif
2926        /*
2927         * Receiving a packet requires that the other end
2928         * be able to write here. Read access is not required.
2929         * This is the simplist possible security model
2930         * for networking.
2931         */
2932        rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2933        if (rc != 0)
2934                netlbl_skbuff_err(skb, rc, 0);
2935        return rc;
2936}
2937
2938/**
2939 * smack_socket_getpeersec_stream - pull in packet label
2940 * @sock: the socket
2941 * @optval: user's destination
2942 * @optlen: size thereof
2943 * @len: max thereof
2944 *
2945 * returns zero on success, an error code otherwise
2946 */
2947static int smack_socket_getpeersec_stream(struct socket *sock,
2948                                          char __user *optval,
2949                                          int __user *optlen, unsigned len)
2950{
2951        struct socket_smack *ssp;
2952        char *rcp = "";
2953        int slen = 1;
2954        int rc = 0;
2955
2956        ssp = sock->sk->sk_security;
2957        if (ssp->smk_packet != NULL) {
2958                rcp = ssp->smk_packet;
2959                slen = strlen(rcp) + 1;
2960        }
2961
2962        if (slen > len)
2963                rc = -ERANGE;
2964        else if (copy_to_user(optval, rcp, slen) != 0)
2965                rc = -EFAULT;
2966
2967        if (put_user(slen, optlen) != 0)
2968                rc = -EFAULT;
2969
2970        return rc;
2971}
2972
2973
2974/**
2975 * smack_socket_getpeersec_dgram - pull in packet label
2976 * @sock: the peer socket
2977 * @skb: packet data
2978 * @secid: pointer to where to put the secid of the packet
2979 *
2980 * Sets the netlabel socket state on sk from parent
2981 */
2982static int smack_socket_getpeersec_dgram(struct socket *sock,
2983                                         struct sk_buff *skb, u32 *secid)
2984
2985{
2986        struct netlbl_lsm_secattr secattr;
2987        struct socket_smack *ssp = NULL;
2988        char *sp;
2989        int family = PF_UNSPEC;
2990        u32 s = 0;      /* 0 is the invalid secid */
2991        int rc;
2992
2993        if (skb != NULL) {
2994                if (skb->protocol == htons(ETH_P_IP))
2995                        family = PF_INET;
2996                else if (skb->protocol == htons(ETH_P_IPV6))
2997                        family = PF_INET6;
2998        }
2999        if (family == PF_UNSPEC && sock != NULL)
3000                family = sock->sk->sk_family;
3001
3002        if (family == PF_UNIX) {
3003                ssp = sock->sk->sk_security;
3004                s = smack_to_secid(ssp->smk_out);
3005        } else if (family == PF_INET || family == PF_INET6) {
3006                /*
3007                 * Translate what netlabel gave us.
3008                 */
3009                if (sock != NULL && sock->sk != NULL)
3010                        ssp = sock->sk->sk_security;
3011                netlbl_secattr_init(&secattr);
3012                rc = netlbl_skbuff_getattr(skb, family, &secattr);
3013                if (rc == 0) {
3014                        sp = smack_from_secattr(&secattr, ssp);
3015                        s = smack_to_secid(sp);
3016                }
3017                netlbl_secattr_destroy(&secattr);
3018        }
3019        *secid = s;
3020        if (s == 0)
3021                return -EINVAL;
3022        return 0;
3023}
3024
3025/**
3026 * smack_sock_graft - Initialize a newly created socket with an existing sock
3027 * @sk: child sock
3028 * @parent: parent socket
3029 *
3030 * Set the smk_{in,out} state of an existing sock based on the process that
3031 * is creating the new socket.
3032 */
3033static void smack_sock_graft(struct sock *sk, struct socket *parent)
3034{
3035        struct socket_smack *ssp;
3036
3037        if (sk == NULL ||
3038            (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3039                return;
3040
3041        ssp = sk->sk_security;
3042        ssp->smk_in = ssp->smk_out = smk_of_current();
3043        /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3044}
3045
3046/**
3047 * smack_inet_conn_request - Smack access check on connect
3048 * @sk: socket involved
3049 * @skb: packet
3050 * @req: unused
3051 *
3052 * Returns 0 if a task with the packet label could write to
3053 * the socket, otherwise an error code
3054 */
3055static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3056                                   struct request_sock *req)
3057{
3058        u16 family = sk->sk_family;
3059        struct smack_known *skp;
3060        struct socket_smack *ssp = sk->sk_security;
3061        struct netlbl_lsm_secattr secattr;
3062        struct sockaddr_in addr;
3063        struct iphdr *hdr;
3064        char *sp;
3065        char *hsp;
3066        int rc;
3067        struct smk_audit_info ad;
3068#ifdef CONFIG_AUDIT
3069        struct lsm_network_audit net;
3070#endif
3071
3072        /* handle mapped IPv4 packets arriving via IPv6 sockets */
3073        if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3074                family = PF_INET;
3075
3076        netlbl_secattr_init(&secattr);
3077        rc = netlbl_skbuff_getattr(skb, family, &secattr);
3078        if (rc == 0)
3079                sp = smack_from_secattr(&secattr, ssp);
3080        else
3081                sp = smack_known_huh.smk_known;
3082        netlbl_secattr_destroy(&secattr);
3083
3084#ifdef CONFIG_AUDIT
3085        smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3086        ad.a.u.net->family = family;
3087        ad.a.u.net->netif = skb->skb_iif;
3088        ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3089#endif
3090        /*
3091         * Receiving a packet requires that the other end be able to write
3092         * here. Read access is not required.
3093         */
3094        rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad);
3095        if (rc != 0)
3096                return rc;
3097
3098        /*
3099         * Save the peer's label in the request_sock so we can later setup
3100         * smk_packet in the child socket so that SO_PEERCRED can report it.
3101         */
3102        req->peer_secid = smack_to_secid(sp);
3103
3104        /*
3105         * We need to decide if we want to label the incoming connection here
3106         * if we do we only need to label the request_sock and the stack will
3107         * propagate the wire-label to the sock when it is created.
3108         */
3109        hdr = ip_hdr(skb);
3110        addr.sin_addr.s_addr = hdr->saddr;
3111        rcu_read_lock();
3112        hsp = smack_host_label(&addr);
3113        rcu_read_unlock();
3114
3115        if (hsp == NULL) {
3116                skp = smk_find_entry(sp);
3117                rc = netlbl_req_setattr(req, &skp->smk_netlabel);
3118        } else
3119                netlbl_req_delattr(req);
3120
3121        return rc;
3122}
3123
3124/**
3125 * smack_inet_csk_clone - Copy the connection information to the new socket
3126 * @sk: the new socket
3127 * @req: the connection's request_sock
3128 *
3129 * Transfer the connection's peer label to the newly created socket.
3130 */
3131static void smack_inet_csk_clone(struct sock *sk,
3132                                 const struct request_sock *req)
3133{
3134        struct socket_smack *ssp = sk->sk_security;
3135
3136        if (req->peer_secid != 0)
3137                ssp->smk_packet = smack_from_secid(req->peer_secid);
3138        else
3139                ssp->smk_packet = NULL;
3140}
3141
3142/*
3143 * Key management security hooks
3144 *
3145 * Casey has not tested key support very heavily.
3146 * The permission check is most likely too restrictive.
3147 * If you care about keys please have a look.
3148 */
3149#ifdef CONFIG_KEYS
3150
3151/**
3152 * smack_key_alloc - Set the key security blob
3153 * @key: object
3154 * @cred: the credentials to use
3155 * @flags: unused
3156 *
3157 * No allocation required
3158 *
3159 * Returns 0
3160 */
3161static int smack_key_alloc(struct key *key, const struct cred *cred,
3162                           unsigned long flags)
3163{
3164        key->security = smk_of_task(cred->security);
3165        return 0;
3166}
3167
3168/**
3169 * smack_key_free - Clear the key security blob
3170 * @key: the object
3171 *
3172 * Clear the blob pointer
3173 */
3174static void smack_key_free(struct key *key)
3175{
3176        key->security = NULL;
3177}
3178
3179/*
3180 * smack_key_permission - Smack access on a key
3181 * @key_ref: gets to the object
3182 * @cred: the credentials to use
3183 * @perm: unused
3184 *
3185 * Return 0 if the task has read and write to the object,
3186 * an error code otherwise
3187 */
3188static int smack_key_permission(key_ref_t key_ref,
3189                                const struct cred *cred, key_perm_t perm)
3190{
3191        struct key *keyp;
3192        struct smk_audit_info ad;
3193        char *tsp = smk_of_task(cred->security);
3194
3195        keyp = key_ref_to_ptr(key_ref);
3196        if (keyp == NULL)
3197                return -EINVAL;
3198        /*
3199         * If the key hasn't been initialized give it access so that
3200         * it may do so.
3201         */
3202        if (keyp->security == NULL)
3203                return 0;
3204        /*
3205         * This should not occur
3206         */
3207        if (tsp == NULL)
3208                return -EACCES;
3209#ifdef CONFIG_AUDIT
3210        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3211        ad.a.u.key_struct.key = keyp->serial;
3212        ad.a.u.key_struct.key_desc = keyp->description;
3213#endif
3214        return smk_access(tsp, keyp->security,
3215                                 MAY_READWRITE, &ad);
3216}
3217#endif /* CONFIG_KEYS */
3218
3219/*
3220 * Smack Audit hooks
3221 *
3222 * Audit requires a unique representation of each Smack specific
3223 * rule. This unique representation is used to distinguish the
3224 * object to be audited from remaining kernel objects and also
3225 * works as a glue between the audit hooks.
3226 *
3227 * Since repository entries are added but never deleted, we'll use
3228 * the smack_known label address related to the given audit rule as
3229 * the needed unique representation. This also better fits the smack
3230 * model where nearly everything is a label.
3231 */
3232#ifdef CONFIG_AUDIT
3233
3234/**
3235 * smack_audit_rule_init - Initialize a smack audit rule
3236 * @field: audit rule fields given from user-space (audit.h)
3237 * @op: required testing operator (=, !=, >, <, ...)
3238 * @rulestr: smack label to be audited
3239 * @vrule: pointer to save our own audit rule representation
3240 *
3241 * Prepare to audit cases where (@field @op @rulestr) is true.
3242 * The label to be audited is created if necessay.
3243 */
3244static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3245{
3246        char **rule = (char **)vrule;
3247        *rule = NULL;
3248
3249        if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3250                return -EINVAL;
3251
3252        if (op != Audit_equal && op != Audit_not_equal)
3253                return -EINVAL;
3254
3255        *rule = smk_import(rulestr, 0);
3256
3257        return 0;
3258}
3259
3260/**
3261 * smack_audit_rule_known - Distinguish Smack audit rules
3262 * @krule: rule of interest, in Audit kernel representation format
3263 *
3264 * This is used to filter Smack rules from remaining Audit ones.
3265 * If it's proved that this rule belongs to us, the
3266 * audit_rule_match hook will be called to do the final judgement.
3267 */
3268static int smack_audit_rule_known(struct audit_krule *krule)
3269{
3270        struct audit_field *f;
3271        int i;
3272
3273        for (i = 0; i < krule->field_count; i++) {
3274                f = &krule->fields[i];
3275
3276                if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3277                        return 1;
3278        }
3279
3280        return 0;
3281}
3282
3283/**
3284 * smack_audit_rule_match - Audit given object ?
3285 * @secid: security id for identifying the object to test
3286 * @field: audit rule flags given from user-space
3287 * @op: required testing operator
3288 * @vrule: smack internal rule presentation
3289 * @actx: audit context associated with the check
3290 *
3291 * The core Audit hook. It's used to take the decision of
3292 * whether to audit or not to audit a given object.
3293 */
3294static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3295                                  struct audit_context *actx)
3296{
3297        char *smack;
3298        char *rule = vrule;
3299
3300        if (!rule) {
3301                audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3302                          "Smack: missing rule\n");
3303                return -ENOENT;
3304        }
3305
3306        if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3307                return 0;
3308
3309        smack = smack_from_secid(secid);
3310
3311        /*
3312         * No need to do string comparisons. If a match occurs,
3313         * both pointers will point to the same smack_known
3314         * label.
3315         */
3316        if (op == Audit_equal)
3317                return (rule == smack);
3318        if (op == Audit_not_equal)
3319                return (rule != smack);
3320
3321        return 0;
3322}
3323
3324/**
3325 * smack_audit_rule_free - free smack rule representation
3326 * @vrule: rule to be freed.
3327 *
3328 * No memory was allocated.
3329 */
3330static void smack_audit_rule_free(void *vrule)
3331{
3332        /* No-op */
3333}
3334
3335#endif /* CONFIG_AUDIT */
3336
3337/**
3338 * smack_secid_to_secctx - return the smack label for a secid
3339 * @secid: incoming integer
3340 * @secdata: destination
3341 * @seclen: how long it is
3342 *
3343 * Exists for networking code.
3344 */
3345static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3346{
3347        char *sp = smack_from_secid(secid);
3348
3349        if (secdata)
3350                *secdata = sp;
3351        *seclen = strlen(sp);
3352        return 0;
3353}
3354
3355/**
3356 * smack_secctx_to_secid - return the secid for a smack label
3357 * @secdata: smack label
3358 * @seclen: how long result is
3359 * @secid: outgoing integer
3360 *
3361 * Exists for audit and networking code.
3362 */
3363static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3364{
3365        *secid = smack_to_secid(secdata);
3366        return 0;
3367}
3368
3369/**
3370 * smack_release_secctx - don't do anything.
3371 * @secdata: unused
3372 * @seclen: unused
3373 *
3374 * Exists to make sure nothing gets done, and properly
3375 */
3376static void smack_release_secctx(char *secdata, u32 seclen)
3377{
3378}
3379
3380static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3381{
3382        return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3383}
3384
3385static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3386{
3387        return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3388}
3389
3390static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3391{
3392        int len = 0;
3393        len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3394
3395        if (len < 0)
3396                return len;
3397        *ctxlen = len;
3398        return 0;
3399}
3400
3401struct security_operations smack_ops = {
3402        .name =                         "smack",
3403
3404        .ptrace_access_check =          smack_ptrace_access_check,
3405        .ptrace_traceme =               smack_ptrace_traceme,
3406        .syslog =                       smack_syslog,
3407
3408        .sb_alloc_security =            smack_sb_alloc_security,
3409        .sb_free_security =             smack_sb_free_security,
3410        .sb_copy_data =                 smack_sb_copy_data,
3411        .sb_kern_mount =                smack_sb_kern_mount,
3412        .sb_statfs =                    smack_sb_statfs,
3413        .sb_mount =                     smack_sb_mount,
3414        .sb_umount =                    smack_sb_umount,
3415
3416        .bprm_set_creds =               smack_bprm_set_creds,
3417        .bprm_committing_creds =        smack_bprm_committing_creds,
3418        .bprm_secureexec =              smack_bprm_secureexec,
3419
3420        .inode_alloc_security =         smack_inode_alloc_security,
3421        .inode_free_security =          smack_inode_free_security,
3422        .inode_init_security =          smack_inode_init_security,
3423        .inode_link =                   smack_inode_link,
3424        .inode_unlink =                 smack_inode_unlink,
3425        .inode_rmdir =                  smack_inode_rmdir,
3426        .inode_rename =                 smack_inode_rename,
3427        .inode_permission =             smack_inode_permission,
3428        .inode_setattr =                smack_inode_setattr,
3429        .inode_getattr =                smack_inode_getattr,
3430        .inode_setxattr =               smack_inode_setxattr,
3431        .inode_post_setxattr =          smack_inode_post_setxattr,
3432        .inode_getxattr =               smack_inode_getxattr,
3433        .inode_removexattr =            smack_inode_removexattr,
3434        .inode_getsecurity =            smack_inode_getsecurity,
3435        .inode_setsecurity =            smack_inode_setsecurity,
3436        .inode_listsecurity =           smack_inode_listsecurity,
3437        .inode_getsecid =               smack_inode_getsecid,
3438
3439        .file_permission =              smack_file_permission,
3440        .file_alloc_security =          smack_file_alloc_security,
3441        .file_free_security =           smack_file_free_security,
3442        .file_ioctl =                   smack_file_ioctl,
3443        .file_lock =                    smack_file_lock,
3444        .file_fcntl =                   smack_file_fcntl,
3445        .mmap_file =                    smack_mmap_file,
3446        .mmap_addr =                    cap_mmap_addr,
3447        .file_set_fowner =              smack_file_set_fowner,
3448        .file_send_sigiotask =          smack_file_send_sigiotask,
3449        .file_receive =                 smack_file_receive,
3450
3451        .file_open =                    smack_file_open,
3452
3453        .cred_alloc_blank =             smack_cred_alloc_blank,
3454        .cred_free =                    smack_cred_free,
3455        .cred_prepare =                 smack_cred_prepare,
3456        .cred_transfer =                smack_cred_transfer,
3457        .kernel_act_as =                smack_kernel_act_as,
3458        .kernel_create_files_as =       smack_kernel_create_files_as,
3459        .task_setpgid =                 smack_task_setpgid,
3460        .task_getpgid =                 smack_task_getpgid,
3461        .task_getsid =                  smack_task_getsid,
3462        .task_getsecid =                smack_task_getsecid,
3463        .task_setnice =                 smack_task_setnice,
3464        .task_setioprio =               smack_task_setioprio,
3465        .task_getioprio =               smack_task_getioprio,
3466        .task_setscheduler =            smack_task_setscheduler,
3467        .task_getscheduler =            smack_task_getscheduler,
3468        .task_movememory =              smack_task_movememory,
3469        .task_kill =                    smack_task_kill,
3470        .task_wait =                    smack_task_wait,
3471        .task_to_inode =                smack_task_to_inode,
3472
3473        .ipc_permission =               smack_ipc_permission,
3474        .ipc_getsecid =                 smack_ipc_getsecid,
3475
3476        .msg_msg_alloc_security =       smack_msg_msg_alloc_security,
3477        .msg_msg_free_security =        smack_msg_msg_free_security,
3478
3479        .msg_queue_alloc_security =     smack_msg_queue_alloc_security,
3480        .msg_queue_free_security =      smack_msg_queue_free_security,
3481        .msg_queue_associate =          smack_msg_queue_associate,
3482        .msg_queue_msgctl =             smack_msg_queue_msgctl,
3483        .msg_queue_msgsnd =             smack_msg_queue_msgsnd,
3484        .msg_queue_msgrcv =             smack_msg_queue_msgrcv,
3485
3486        .shm_alloc_security =           smack_shm_alloc_security,
3487        .shm_free_security =            smack_shm_free_security,
3488        .shm_associate =                smack_shm_associate,
3489        .shm_shmctl =                   smack_shm_shmctl,
3490        .shm_shmat =                    smack_shm_shmat,
3491
3492        .sem_alloc_security =           smack_sem_alloc_security,
3493        .sem_free_security =            smack_sem_free_security,
3494        .sem_associate =                smack_sem_associate,
3495        .sem_semctl =                   smack_sem_semctl,
3496        .sem_semop =                    smack_sem_semop,
3497
3498        .d_instantiate =                smack_d_instantiate,
3499
3500        .getprocattr =                  smack_getprocattr,
3501        .setprocattr =                  smack_setprocattr,
3502
3503        .unix_stream_connect =          smack_unix_stream_connect,
3504        .unix_may_send =                smack_unix_may_send,
3505
3506        .socket_post_create =           smack_socket_post_create,
3507        .socket_connect =               smack_socket_connect,
3508        .socket_sendmsg =               smack_socket_sendmsg,
3509        .socket_sock_rcv_skb =          smack_socket_sock_rcv_skb,
3510        .socket_getpeersec_stream =     smack_socket_getpeersec_stream,
3511        .socket_getpeersec_dgram =      smack_socket_getpeersec_dgram,
3512        .sk_alloc_security =            smack_sk_alloc_security,
3513        .sk_free_security =             smack_sk_free_security,
3514        .sock_graft =                   smack_sock_graft,
3515        .inet_conn_request =            smack_inet_conn_request,
3516        .inet_csk_clone =               smack_inet_csk_clone,
3517
3518 /* key management security hooks */
3519#ifdef CONFIG_KEYS
3520        .key_alloc =                    smack_key_alloc,
3521        .key_free =                     smack_key_free,
3522        .key_permission =               smack_key_permission,
3523#endif /* CONFIG_KEYS */
3524
3525 /* Audit hooks */
3526#ifdef CONFIG_AUDIT
3527        .audit_rule_init =              smack_audit_rule_init,
3528        .audit_rule_known =             smack_audit_rule_known,
3529        .audit_rule_match =             smack_audit_rule_match,
3530        .audit_rule_free =              smack_audit_rule_free,
3531#endif /* CONFIG_AUDIT */
3532
3533        .secid_to_secctx =              smack_secid_to_secctx,
3534        .secctx_to_secid =              smack_secctx_to_secid,
3535        .release_secctx =               smack_release_secctx,
3536        .inode_notifysecctx =           smack_inode_notifysecctx,
3537        .inode_setsecctx =              smack_inode_setsecctx,
3538        .inode_getsecctx =              smack_inode_getsecctx,
3539};
3540
3541
3542static __init void init_smack_known_list(void)
3543{
3544        /*
3545         * Initialize rule list locks
3546         */
3547        mutex_init(&smack_known_huh.smk_rules_lock);
3548        mutex_init(&smack_known_hat.smk_rules_lock);
3549        mutex_init(&smack_known_floor.smk_rules_lock);
3550        mutex_init(&smack_known_star.smk_rules_lock);
3551        mutex_init(&smack_known_invalid.smk_rules_lock);
3552        mutex_init(&smack_known_web.smk_rules_lock);
3553        /*
3554         * Initialize rule lists
3555         */
3556        INIT_LIST_HEAD(&smack_known_huh.smk_rules);
3557        INIT_LIST_HEAD(&smack_known_hat.smk_rules);
3558        INIT_LIST_HEAD(&smack_known_star.smk_rules);
3559        INIT_LIST_HEAD(&smack_known_floor.smk_rules);
3560        INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
3561        INIT_LIST_HEAD(&smack_known_web.smk_rules);
3562        /*
3563         * Create the known labels list
3564         */
3565        list_add(&smack_known_huh.list, &smack_known_list);
3566        list_add(&smack_known_hat.list, &smack_known_list);
3567        list_add(&smack_known_star.list, &smack_known_list);
3568        list_add(&smack_known_floor.list, &smack_known_list);
3569        list_add(&smack_known_invalid.list, &smack_known_list);
3570        list_add(&smack_known_web.list, &smack_known_list);
3571}
3572
3573/**
3574 * smack_init - initialize the smack system
3575 *
3576 * Returns 0
3577 */
3578static __init int smack_init(void)
3579{
3580        struct cred *cred;
3581        struct task_smack *tsp;
3582
3583        if (!security_module_enable(&smack_ops))
3584                return 0;
3585
3586        tsp = new_task_smack(smack_known_floor.smk_known,
3587                                smack_known_floor.smk_known, GFP_KERNEL);
3588        if (tsp == NULL)
3589                return -ENOMEM;
3590
3591        printk(KERN_INFO "Smack:  Initializing.\n");
3592
3593        /*
3594         * Set the security state for the initial task.
3595         */
3596        cred = (struct cred *) current->cred;
3597        cred->security = tsp;
3598
3599        /* initialize the smack_known_list */
3600        init_smack_known_list();
3601
3602        /*
3603         * Register with LSM
3604         */
3605        if (register_security(&smack_ops))
3606                panic("smack: Unable to register with kernel.\n");
3607
3608        return 0;
3609}
3610
3611/*
3612 * Smack requires early initialization in order to label
3613 * all processes and objects when they are created.
3614 */
3615security_initcall(smack_init);
3616
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