linux/security/apparmor/lsm.c
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   1/*
   2 * AppArmor security module
   3 *
   4 * This file contains AppArmor LSM hooks.
   5 *
   6 * Copyright (C) 1998-2008 Novell/SUSE
   7 * Copyright 2009-2010 Canonical Ltd.
   8 *
   9 * This program is free software; you can redistribute it and/or
  10 * modify it under the terms of the GNU General Public License as
  11 * published by the Free Software Foundation, version 2 of the
  12 * License.
  13 */
  14
  15#include <linux/security.h>
  16#include <linux/moduleparam.h>
  17#include <linux/mm.h>
  18#include <linux/mman.h>
  19#include <linux/mount.h>
  20#include <linux/namei.h>
  21#include <linux/ptrace.h>
  22#include <linux/ctype.h>
  23#include <linux/sysctl.h>
  24#include <linux/audit.h>
  25#include <linux/user_namespace.h>
  26#include <net/sock.h>
  27
  28#include "include/apparmor.h"
  29#include "include/apparmorfs.h"
  30#include "include/audit.h"
  31#include "include/capability.h"
  32#include "include/context.h"
  33#include "include/file.h"
  34#include "include/ipc.h"
  35#include "include/path.h"
  36#include "include/policy.h"
  37#include "include/procattr.h"
  38
  39/* Flag indicating whether initialization completed */
  40int apparmor_initialized __initdata;
  41
  42/*
  43 * LSM hook functions
  44 */
  45
  46/*
  47 * free the associated aa_task_cxt and put its profiles
  48 */
  49static void apparmor_cred_free(struct cred *cred)
  50{
  51        aa_free_task_context(cred->security);
  52        cred->security = NULL;
  53}
  54
  55/*
  56 * allocate the apparmor part of blank credentials
  57 */
  58static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
  59{
  60        /* freed by apparmor_cred_free */
  61        struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
  62        if (!cxt)
  63                return -ENOMEM;
  64
  65        cred->security = cxt;
  66        return 0;
  67}
  68
  69/*
  70 * prepare new aa_task_cxt for modification by prepare_cred block
  71 */
  72static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
  73                                 gfp_t gfp)
  74{
  75        /* freed by apparmor_cred_free */
  76        struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
  77        if (!cxt)
  78                return -ENOMEM;
  79
  80        aa_dup_task_context(cxt, old->security);
  81        new->security = cxt;
  82        return 0;
  83}
  84
  85/*
  86 * transfer the apparmor data to a blank set of creds
  87 */
  88static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
  89{
  90        const struct aa_task_cxt *old_cxt = old->security;
  91        struct aa_task_cxt *new_cxt = new->security;
  92
  93        aa_dup_task_context(new_cxt, old_cxt);
  94}
  95
  96static int apparmor_ptrace_access_check(struct task_struct *child,
  97                                        unsigned int mode)
  98{
  99        int error = cap_ptrace_access_check(child, mode);
 100        if (error)
 101                return error;
 102
 103        return aa_ptrace(current, child, mode);
 104}
 105
 106static int apparmor_ptrace_traceme(struct task_struct *parent)
 107{
 108        int error = cap_ptrace_traceme(parent);
 109        if (error)
 110                return error;
 111
 112        return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
 113}
 114
 115/* Derived from security/commoncap.c:cap_capget */
 116static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
 117                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
 118{
 119        struct aa_profile *profile;
 120        const struct cred *cred;
 121
 122        rcu_read_lock();
 123        cred = __task_cred(target);
 124        profile = aa_cred_profile(cred);
 125
 126        *effective = cred->cap_effective;
 127        *inheritable = cred->cap_inheritable;
 128        *permitted = cred->cap_permitted;
 129
 130        if (!unconfined(profile) && !COMPLAIN_MODE(profile)) {
 131                *effective = cap_intersect(*effective, profile->caps.allow);
 132                *permitted = cap_intersect(*permitted, profile->caps.allow);
 133        }
 134        rcu_read_unlock();
 135
 136        return 0;
 137}
 138
 139static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
 140                            int cap, int audit)
 141{
 142        struct aa_profile *profile;
 143        /* cap_capable returns 0 on success, else -EPERM */
 144        int error = cap_capable(cred, ns, cap, audit);
 145        if (!error) {
 146                profile = aa_cred_profile(cred);
 147                if (!unconfined(profile))
 148                        error = aa_capable(current, profile, cap, audit);
 149        }
 150        return error;
 151}
 152
 153/**
 154 * common_perm - basic common permission check wrapper fn for paths
 155 * @op: operation being checked
 156 * @path: path to check permission of  (NOT NULL)
 157 * @mask: requested permissions mask
 158 * @cond: conditional info for the permission request  (NOT NULL)
 159 *
 160 * Returns: %0 else error code if error or permission denied
 161 */
 162static int common_perm(int op, struct path *path, u32 mask,
 163                       struct path_cond *cond)
 164{
 165        struct aa_profile *profile;
 166        int error = 0;
 167
 168        profile = __aa_current_profile();
 169        if (!unconfined(profile))
 170                error = aa_path_perm(op, profile, path, 0, mask, cond);
 171
 172        return error;
 173}
 174
 175/**
 176 * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
 177 * @op: operation being checked
 178 * @dir: directory of the dentry  (NOT NULL)
 179 * @dentry: dentry to check  (NOT NULL)
 180 * @mask: requested permissions mask
 181 * @cond: conditional info for the permission request  (NOT NULL)
 182 *
 183 * Returns: %0 else error code if error or permission denied
 184 */
 185static int common_perm_dir_dentry(int op, struct path *dir,
 186                                  struct dentry *dentry, u32 mask,
 187                                  struct path_cond *cond)
 188{
 189        struct path path = { dir->mnt, dentry };
 190
 191        return common_perm(op, &path, mask, cond);
 192}
 193
 194/**
 195 * common_perm_mnt_dentry - common permission wrapper when mnt, dentry
 196 * @op: operation being checked
 197 * @mnt: mount point of dentry (NOT NULL)
 198 * @dentry: dentry to check  (NOT NULL)
 199 * @mask: requested permissions mask
 200 *
 201 * Returns: %0 else error code if error or permission denied
 202 */
 203static int common_perm_mnt_dentry(int op, struct vfsmount *mnt,
 204                                  struct dentry *dentry, u32 mask)
 205{
 206        struct path path = { mnt, dentry };
 207        struct path_cond cond = { dentry->d_inode->i_uid,
 208                                  dentry->d_inode->i_mode
 209        };
 210
 211        return common_perm(op, &path, mask, &cond);
 212}
 213
 214/**
 215 * common_perm_rm - common permission wrapper for operations doing rm
 216 * @op: operation being checked
 217 * @dir: directory that the dentry is in  (NOT NULL)
 218 * @dentry: dentry being rm'd  (NOT NULL)
 219 * @mask: requested permission mask
 220 *
 221 * Returns: %0 else error code if error or permission denied
 222 */
 223static int common_perm_rm(int op, struct path *dir,
 224                          struct dentry *dentry, u32 mask)
 225{
 226        struct inode *inode = dentry->d_inode;
 227        struct path_cond cond = { };
 228
 229        if (!inode || !dir->mnt || !mediated_filesystem(inode))
 230                return 0;
 231
 232        cond.uid = inode->i_uid;
 233        cond.mode = inode->i_mode;
 234
 235        return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 236}
 237
 238/**
 239 * common_perm_create - common permission wrapper for operations doing create
 240 * @op: operation being checked
 241 * @dir: directory that dentry will be created in  (NOT NULL)
 242 * @dentry: dentry to create   (NOT NULL)
 243 * @mask: request permission mask
 244 * @mode: created file mode
 245 *
 246 * Returns: %0 else error code if error or permission denied
 247 */
 248static int common_perm_create(int op, struct path *dir, struct dentry *dentry,
 249                              u32 mask, umode_t mode)
 250{
 251        struct path_cond cond = { current_fsuid(), mode };
 252
 253        if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode))
 254                return 0;
 255
 256        return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 257}
 258
 259static int apparmor_path_unlink(struct path *dir, struct dentry *dentry)
 260{
 261        return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
 262}
 263
 264static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
 265                               umode_t mode)
 266{
 267        return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
 268                                  S_IFDIR);
 269}
 270
 271static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry)
 272{
 273        return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
 274}
 275
 276static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
 277                               umode_t mode, unsigned int dev)
 278{
 279        return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
 280}
 281
 282static int apparmor_path_truncate(struct path *path)
 283{
 284        struct path_cond cond = { path->dentry->d_inode->i_uid,
 285                                  path->dentry->d_inode->i_mode
 286        };
 287
 288        if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
 289                return 0;
 290
 291        return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
 292                           &cond);
 293}
 294
 295static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
 296                                 const char *old_name)
 297{
 298        return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
 299                                  S_IFLNK);
 300}
 301
 302static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
 303                              struct dentry *new_dentry)
 304{
 305        struct aa_profile *profile;
 306        int error = 0;
 307
 308        if (!mediated_filesystem(old_dentry->d_inode))
 309                return 0;
 310
 311        profile = aa_current_profile();
 312        if (!unconfined(profile))
 313                error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
 314        return error;
 315}
 316
 317static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
 318                                struct path *new_dir, struct dentry *new_dentry)
 319{
 320        struct aa_profile *profile;
 321        int error = 0;
 322
 323        if (!mediated_filesystem(old_dentry->d_inode))
 324                return 0;
 325
 326        profile = aa_current_profile();
 327        if (!unconfined(profile)) {
 328                struct path old_path = { old_dir->mnt, old_dentry };
 329                struct path new_path = { new_dir->mnt, new_dentry };
 330                struct path_cond cond = { old_dentry->d_inode->i_uid,
 331                                          old_dentry->d_inode->i_mode
 332                };
 333
 334                error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
 335                                     MAY_READ | AA_MAY_META_READ | MAY_WRITE |
 336                                     AA_MAY_META_WRITE | AA_MAY_DELETE,
 337                                     &cond);
 338                if (!error)
 339                        error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
 340                                             0, MAY_WRITE | AA_MAY_META_WRITE |
 341                                             AA_MAY_CREATE, &cond);
 342
 343        }
 344        return error;
 345}
 346
 347static int apparmor_path_chmod(struct path *path, umode_t mode)
 348{
 349        if (!mediated_filesystem(path->dentry->d_inode))
 350                return 0;
 351
 352        return common_perm_mnt_dentry(OP_CHMOD, path->mnt, path->dentry, AA_MAY_CHMOD);
 353}
 354
 355static int apparmor_path_chown(struct path *path, uid_t uid, gid_t gid)
 356{
 357        struct path_cond cond =  { path->dentry->d_inode->i_uid,
 358                                   path->dentry->d_inode->i_mode
 359        };
 360
 361        if (!mediated_filesystem(path->dentry->d_inode))
 362                return 0;
 363
 364        return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
 365}
 366
 367static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 368{
 369        if (!mediated_filesystem(dentry->d_inode))
 370                return 0;
 371
 372        return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry,
 373                                      AA_MAY_META_READ);
 374}
 375
 376static int apparmor_file_open(struct file *file, const struct cred *cred)
 377{
 378        struct aa_file_cxt *fcxt = file->f_security;
 379        struct aa_profile *profile;
 380        int error = 0;
 381
 382        if (!mediated_filesystem(file->f_path.dentry->d_inode))
 383                return 0;
 384
 385        /* If in exec, permission is handled by bprm hooks.
 386         * Cache permissions granted by the previous exec check, with
 387         * implicit read and executable mmap which are required to
 388         * actually execute the image.
 389         */
 390        if (current->in_execve) {
 391                fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
 392                return 0;
 393        }
 394
 395        profile = aa_cred_profile(cred);
 396        if (!unconfined(profile)) {
 397                struct inode *inode = file->f_path.dentry->d_inode;
 398                struct path_cond cond = { inode->i_uid, inode->i_mode };
 399
 400                error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
 401                                     aa_map_file_to_perms(file), &cond);
 402                /* todo cache full allowed permissions set and state */
 403                fcxt->allow = aa_map_file_to_perms(file);
 404        }
 405
 406        return error;
 407}
 408
 409static int apparmor_file_alloc_security(struct file *file)
 410{
 411        /* freed by apparmor_file_free_security */
 412        file->f_security = aa_alloc_file_context(GFP_KERNEL);
 413        if (!file->f_security)
 414                return -ENOMEM;
 415        return 0;
 416
 417}
 418
 419static void apparmor_file_free_security(struct file *file)
 420{
 421        struct aa_file_cxt *cxt = file->f_security;
 422
 423        aa_free_file_context(cxt);
 424}
 425
 426static int common_file_perm(int op, struct file *file, u32 mask)
 427{
 428        struct aa_file_cxt *fcxt = file->f_security;
 429        struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
 430        int error = 0;
 431
 432        BUG_ON(!fprofile);
 433
 434        if (!file->f_path.mnt ||
 435            !mediated_filesystem(file->f_path.dentry->d_inode))
 436                return 0;
 437
 438        profile = __aa_current_profile();
 439
 440        /* revalidate access, if task is unconfined, or the cached cred
 441         * doesn't match or if the request is for more permissions than
 442         * was granted.
 443         *
 444         * Note: the test for !unconfined(fprofile) is to handle file
 445         *       delegation from unconfined tasks
 446         */
 447        if (!unconfined(profile) && !unconfined(fprofile) &&
 448            ((fprofile != profile) || (mask & ~fcxt->allow)))
 449                error = aa_file_perm(op, profile, file, mask);
 450
 451        return error;
 452}
 453
 454static int apparmor_file_permission(struct file *file, int mask)
 455{
 456        return common_file_perm(OP_FPERM, file, mask);
 457}
 458
 459static int apparmor_file_lock(struct file *file, unsigned int cmd)
 460{
 461        u32 mask = AA_MAY_LOCK;
 462
 463        if (cmd == F_WRLCK)
 464                mask |= MAY_WRITE;
 465
 466        return common_file_perm(OP_FLOCK, file, mask);
 467}
 468
 469static int common_mmap(int op, struct file *file, unsigned long prot,
 470                       unsigned long flags)
 471{
 472        struct dentry *dentry;
 473        int mask = 0;
 474
 475        if (!file || !file->f_security)
 476                return 0;
 477
 478        if (prot & PROT_READ)
 479                mask |= MAY_READ;
 480        /*
 481         * Private mappings don't require write perms since they don't
 482         * write back to the files
 483         */
 484        if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
 485                mask |= MAY_WRITE;
 486        if (prot & PROT_EXEC)
 487                mask |= AA_EXEC_MMAP;
 488
 489        dentry = file->f_path.dentry;
 490        return common_file_perm(op, file, mask);
 491}
 492
 493static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
 494                              unsigned long prot, unsigned long flags)
 495{
 496        return common_mmap(OP_FMMAP, file, prot, flags);
 497}
 498
 499static int apparmor_file_mprotect(struct vm_area_struct *vma,
 500                                  unsigned long reqprot, unsigned long prot)
 501{
 502        return common_mmap(OP_FMPROT, vma->vm_file, prot,
 503                           !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
 504}
 505
 506static int apparmor_getprocattr(struct task_struct *task, char *name,
 507                                char **value)
 508{
 509        int error = -ENOENT;
 510        struct aa_profile *profile;
 511        /* released below */
 512        const struct cred *cred = get_task_cred(task);
 513        struct aa_task_cxt *cxt = cred->security;
 514        profile = aa_cred_profile(cred);
 515
 516        if (strcmp(name, "current") == 0)
 517                error = aa_getprocattr(aa_newest_version(cxt->profile),
 518                                       value);
 519        else if (strcmp(name, "prev") == 0  && cxt->previous)
 520                error = aa_getprocattr(aa_newest_version(cxt->previous),
 521                                       value);
 522        else if (strcmp(name, "exec") == 0 && cxt->onexec)
 523                error = aa_getprocattr(aa_newest_version(cxt->onexec),
 524                                       value);
 525        else
 526                error = -EINVAL;
 527
 528        put_cred(cred);
 529
 530        return error;
 531}
 532
 533static int apparmor_setprocattr(struct task_struct *task, char *name,
 534                                void *value, size_t size)
 535{
 536        char *command, *args = value;
 537        size_t arg_size;
 538        int error;
 539
 540        if (size == 0)
 541                return -EINVAL;
 542        /* args points to a PAGE_SIZE buffer, AppArmor requires that
 543         * the buffer must be null terminated or have size <= PAGE_SIZE -1
 544         * so that AppArmor can null terminate them
 545         */
 546        if (args[size - 1] != '\0') {
 547                if (size == PAGE_SIZE)
 548                        return -EINVAL;
 549                args[size] = '\0';
 550        }
 551
 552        /* task can only write its own attributes */
 553        if (current != task)
 554                return -EACCES;
 555
 556        args = value;
 557        args = strim(args);
 558        command = strsep(&args, " ");
 559        if (!args)
 560                return -EINVAL;
 561        args = skip_spaces(args);
 562        if (!*args)
 563                return -EINVAL;
 564
 565        arg_size = size - (args - (char *) value);
 566        if (strcmp(name, "current") == 0) {
 567                if (strcmp(command, "changehat") == 0) {
 568                        error = aa_setprocattr_changehat(args, arg_size,
 569                                                         !AA_DO_TEST);
 570                } else if (strcmp(command, "permhat") == 0) {
 571                        error = aa_setprocattr_changehat(args, arg_size,
 572                                                         AA_DO_TEST);
 573                } else if (strcmp(command, "changeprofile") == 0) {
 574                        error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
 575                                                             !AA_DO_TEST);
 576                } else if (strcmp(command, "permprofile") == 0) {
 577                        error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
 578                                                             AA_DO_TEST);
 579                } else if (strcmp(command, "permipc") == 0) {
 580                        error = aa_setprocattr_permipc(args);
 581                } else {
 582                        struct common_audit_data sa;
 583                        struct apparmor_audit_data aad = {0,};
 584                        sa.type = LSM_AUDIT_DATA_NONE;
 585                        sa.aad = &aad;
 586                        aad.op = OP_SETPROCATTR;
 587                        aad.info = name;
 588                        aad.error = -EINVAL;
 589                        return aa_audit(AUDIT_APPARMOR_DENIED,
 590                                        __aa_current_profile(), GFP_KERNEL,
 591                                        &sa, NULL);
 592                }
 593        } else if (strcmp(name, "exec") == 0) {
 594                error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
 595                                                     !AA_DO_TEST);
 596        } else {
 597                /* only support the "current" and "exec" process attributes */
 598                return -EINVAL;
 599        }
 600        if (!error)
 601                error = size;
 602        return error;
 603}
 604
 605static int apparmor_task_setrlimit(struct task_struct *task,
 606                unsigned int resource, struct rlimit *new_rlim)
 607{
 608        struct aa_profile *profile = __aa_current_profile();
 609        int error = 0;
 610
 611        if (!unconfined(profile))
 612                error = aa_task_setrlimit(profile, task, resource, new_rlim);
 613
 614        return error;
 615}
 616
 617static struct security_operations apparmor_ops = {
 618        .name =                         "apparmor",
 619
 620        .ptrace_access_check =          apparmor_ptrace_access_check,
 621        .ptrace_traceme =               apparmor_ptrace_traceme,
 622        .capget =                       apparmor_capget,
 623        .capable =                      apparmor_capable,
 624
 625        .path_link =                    apparmor_path_link,
 626        .path_unlink =                  apparmor_path_unlink,
 627        .path_symlink =                 apparmor_path_symlink,
 628        .path_mkdir =                   apparmor_path_mkdir,
 629        .path_rmdir =                   apparmor_path_rmdir,
 630        .path_mknod =                   apparmor_path_mknod,
 631        .path_rename =                  apparmor_path_rename,
 632        .path_chmod =                   apparmor_path_chmod,
 633        .path_chown =                   apparmor_path_chown,
 634        .path_truncate =                apparmor_path_truncate,
 635        .inode_getattr =                apparmor_inode_getattr,
 636
 637        .file_open =                    apparmor_file_open,
 638        .file_permission =              apparmor_file_permission,
 639        .file_alloc_security =          apparmor_file_alloc_security,
 640        .file_free_security =           apparmor_file_free_security,
 641        .mmap_file =                    apparmor_mmap_file,
 642        .mmap_addr =                    cap_mmap_addr,
 643        .file_mprotect =                apparmor_file_mprotect,
 644        .file_lock =                    apparmor_file_lock,
 645
 646        .getprocattr =                  apparmor_getprocattr,
 647        .setprocattr =                  apparmor_setprocattr,
 648
 649        .cred_alloc_blank =             apparmor_cred_alloc_blank,
 650        .cred_free =                    apparmor_cred_free,
 651        .cred_prepare =                 apparmor_cred_prepare,
 652        .cred_transfer =                apparmor_cred_transfer,
 653
 654        .bprm_set_creds =               apparmor_bprm_set_creds,
 655        .bprm_committing_creds =        apparmor_bprm_committing_creds,
 656        .bprm_committed_creds =         apparmor_bprm_committed_creds,
 657        .bprm_secureexec =              apparmor_bprm_secureexec,
 658
 659        .task_setrlimit =               apparmor_task_setrlimit,
 660};
 661
 662/*
 663 * AppArmor sysfs module parameters
 664 */
 665
 666static int param_set_aabool(const char *val, const struct kernel_param *kp);
 667static int param_get_aabool(char *buffer, const struct kernel_param *kp);
 668#define param_check_aabool param_check_bool
 669static struct kernel_param_ops param_ops_aabool = {
 670        .set = param_set_aabool,
 671        .get = param_get_aabool
 672};
 673
 674static int param_set_aauint(const char *val, const struct kernel_param *kp);
 675static int param_get_aauint(char *buffer, const struct kernel_param *kp);
 676#define param_check_aauint param_check_uint
 677static struct kernel_param_ops param_ops_aauint = {
 678        .set = param_set_aauint,
 679        .get = param_get_aauint
 680};
 681
 682static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
 683static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
 684#define param_check_aalockpolicy param_check_bool
 685static struct kernel_param_ops param_ops_aalockpolicy = {
 686        .set = param_set_aalockpolicy,
 687        .get = param_get_aalockpolicy
 688};
 689
 690static int param_set_audit(const char *val, struct kernel_param *kp);
 691static int param_get_audit(char *buffer, struct kernel_param *kp);
 692
 693static int param_set_mode(const char *val, struct kernel_param *kp);
 694static int param_get_mode(char *buffer, struct kernel_param *kp);
 695
 696/* Flag values, also controllable via /sys/module/apparmor/parameters
 697 * We define special types as we want to do additional mediation.
 698 */
 699
 700/* AppArmor global enforcement switch - complain, enforce, kill */
 701enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
 702module_param_call(mode, param_set_mode, param_get_mode,
 703                  &aa_g_profile_mode, S_IRUSR | S_IWUSR);
 704
 705/* Debug mode */
 706bool aa_g_debug;
 707module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
 708
 709/* Audit mode */
 710enum audit_mode aa_g_audit;
 711module_param_call(audit, param_set_audit, param_get_audit,
 712                  &aa_g_audit, S_IRUSR | S_IWUSR);
 713
 714/* Determines if audit header is included in audited messages.  This
 715 * provides more context if the audit daemon is not running
 716 */
 717bool aa_g_audit_header = 1;
 718module_param_named(audit_header, aa_g_audit_header, aabool,
 719                   S_IRUSR | S_IWUSR);
 720
 721/* lock out loading/removal of policy
 722 * TODO: add in at boot loading of policy, which is the only way to
 723 *       load policy, if lock_policy is set
 724 */
 725bool aa_g_lock_policy;
 726module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
 727                   S_IRUSR | S_IWUSR);
 728
 729/* Syscall logging mode */
 730bool aa_g_logsyscall;
 731module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
 732
 733/* Maximum pathname length before accesses will start getting rejected */
 734unsigned int aa_g_path_max = 2 * PATH_MAX;
 735module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
 736
 737/* Determines how paranoid loading of policy is and how much verification
 738 * on the loaded policy is done.
 739 */
 740bool aa_g_paranoid_load = 1;
 741module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
 742                   S_IRUSR | S_IWUSR);
 743
 744/* Boot time disable flag */
 745static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
 746module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);
 747
 748static int __init apparmor_enabled_setup(char *str)
 749{
 750        unsigned long enabled;
 751        int error = strict_strtoul(str, 0, &enabled);
 752        if (!error)
 753                apparmor_enabled = enabled ? 1 : 0;
 754        return 1;
 755}
 756
 757__setup("apparmor=", apparmor_enabled_setup);
 758
 759/* set global flag turning off the ability to load policy */
 760static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
 761{
 762        if (!capable(CAP_MAC_ADMIN))
 763                return -EPERM;
 764        if (aa_g_lock_policy)
 765                return -EACCES;
 766        return param_set_bool(val, kp);
 767}
 768
 769static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
 770{
 771        if (!capable(CAP_MAC_ADMIN))
 772                return -EPERM;
 773        return param_get_bool(buffer, kp);
 774}
 775
 776static int param_set_aabool(const char *val, const struct kernel_param *kp)
 777{
 778        if (!capable(CAP_MAC_ADMIN))
 779                return -EPERM;
 780        return param_set_bool(val, kp);
 781}
 782
 783static int param_get_aabool(char *buffer, const struct kernel_param *kp)
 784{
 785        if (!capable(CAP_MAC_ADMIN))
 786                return -EPERM;
 787        return param_get_bool(buffer, kp);
 788}
 789
 790static int param_set_aauint(const char *val, const struct kernel_param *kp)
 791{
 792        if (!capable(CAP_MAC_ADMIN))
 793                return -EPERM;
 794        return param_set_uint(val, kp);
 795}
 796
 797static int param_get_aauint(char *buffer, const struct kernel_param *kp)
 798{
 799        if (!capable(CAP_MAC_ADMIN))
 800                return -EPERM;
 801        return param_get_uint(buffer, kp);
 802}
 803
 804static int param_get_audit(char *buffer, struct kernel_param *kp)
 805{
 806        if (!capable(CAP_MAC_ADMIN))
 807                return -EPERM;
 808
 809        if (!apparmor_enabled)
 810                return -EINVAL;
 811
 812        return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
 813}
 814
 815static int param_set_audit(const char *val, struct kernel_param *kp)
 816{
 817        int i;
 818        if (!capable(CAP_MAC_ADMIN))
 819                return -EPERM;
 820
 821        if (!apparmor_enabled)
 822                return -EINVAL;
 823
 824        if (!val)
 825                return -EINVAL;
 826
 827        for (i = 0; i < AUDIT_MAX_INDEX; i++) {
 828                if (strcmp(val, audit_mode_names[i]) == 0) {
 829                        aa_g_audit = i;
 830                        return 0;
 831                }
 832        }
 833
 834        return -EINVAL;
 835}
 836
 837static int param_get_mode(char *buffer, struct kernel_param *kp)
 838{
 839        if (!capable(CAP_MAC_ADMIN))
 840                return -EPERM;
 841
 842        if (!apparmor_enabled)
 843                return -EINVAL;
 844
 845        return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
 846}
 847
 848static int param_set_mode(const char *val, struct kernel_param *kp)
 849{
 850        int i;
 851        if (!capable(CAP_MAC_ADMIN))
 852                return -EPERM;
 853
 854        if (!apparmor_enabled)
 855                return -EINVAL;
 856
 857        if (!val)
 858                return -EINVAL;
 859
 860        for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
 861                if (strcmp(val, profile_mode_names[i]) == 0) {
 862                        aa_g_profile_mode = i;
 863                        return 0;
 864                }
 865        }
 866
 867        return -EINVAL;
 868}
 869
 870/*
 871 * AppArmor init functions
 872 */
 873
 874/**
 875 * set_init_cxt - set a task context and profile on the first task.
 876 *
 877 * TODO: allow setting an alternate profile than unconfined
 878 */
 879static int __init set_init_cxt(void)
 880{
 881        struct cred *cred = (struct cred *)current->real_cred;
 882        struct aa_task_cxt *cxt;
 883
 884        cxt = aa_alloc_task_context(GFP_KERNEL);
 885        if (!cxt)
 886                return -ENOMEM;
 887
 888        cxt->profile = aa_get_profile(root_ns->unconfined);
 889        cred->security = cxt;
 890
 891        return 0;
 892}
 893
 894static int __init apparmor_init(void)
 895{
 896        int error;
 897
 898        if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
 899                aa_info_message("AppArmor disabled by boot time parameter");
 900                apparmor_enabled = 0;
 901                return 0;
 902        }
 903
 904        error = aa_alloc_root_ns();
 905        if (error) {
 906                AA_ERROR("Unable to allocate default profile namespace\n");
 907                goto alloc_out;
 908        }
 909
 910        error = set_init_cxt();
 911        if (error) {
 912                AA_ERROR("Failed to set context on init task\n");
 913                goto register_security_out;
 914        }
 915
 916        error = register_security(&apparmor_ops);
 917        if (error) {
 918                AA_ERROR("Unable to register AppArmor\n");
 919                goto set_init_cxt_out;
 920        }
 921
 922        /* Report that AppArmor successfully initialized */
 923        apparmor_initialized = 1;
 924        if (aa_g_profile_mode == APPARMOR_COMPLAIN)
 925                aa_info_message("AppArmor initialized: complain mode enabled");
 926        else if (aa_g_profile_mode == APPARMOR_KILL)
 927                aa_info_message("AppArmor initialized: kill mode enabled");
 928        else
 929                aa_info_message("AppArmor initialized");
 930
 931        return error;
 932
 933set_init_cxt_out:
 934        aa_free_task_context(current->real_cred->security);
 935
 936register_security_out:
 937        aa_free_root_ns();
 938
 939alloc_out:
 940        aa_destroy_aafs();
 941
 942        apparmor_enabled = 0;
 943        return error;
 944}
 945
 946security_initcall(apparmor_init);
 947
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