security/apparmor/lsm.c

   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/lsm_hooks.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 <linux/kmemleak.h>
  27 #include <net/sock.h>
  28
  29 #include "include/apparmor.h"
  30 #include "include/apparmorfs.h"
  31 #include "include/audit.h"
  32 #include "include/capability.h"
  33 #include "include/context.h"
  34 #include "include/file.h"
  35 #include "include/ipc.h"
  36 #include "include/path.h"
  37 #include "include/policy.h"
  38 #include "include/policy_ns.h"
  39 #include "include/procattr.h"
  40
  41 /* Flag indicating whether initialization completed */
  42 int apparmor_initialized __initdata;
  43
  44 DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
  45
  46
  47 /*
  48  * LSM hook functions
  49  */
  50
  51 /*
  52  * free the associated aa_task_ctx and put its profiles
  53  */
  54 static void apparmor_cred_free(struct cred *cred)
  55 {
  56         aa_free_task_context(cred_ctx(cred));
  57         cred_ctx(cred) = NULL;
  58 }
  59
  60 /*
  61  * allocate the apparmor part of blank credentials
  62  */
  63 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
  64 {
  65         /* freed by apparmor_cred_free */
  66         struct aa_task_ctx *ctx = aa_alloc_task_context(gfp);
  67
  68         if (!ctx)
  69                 return -ENOMEM;
  70
  71         cred_ctx(cred) = ctx;
  72         return 0;
  73 }
  74
  75 /*
  76  * prepare new aa_task_ctx for modification by prepare_cred block
  77  */
  78 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
  79                                  gfp_t gfp)
  80 {
  81         /* freed by apparmor_cred_free */
  82         struct aa_task_ctx *ctx = aa_alloc_task_context(gfp);
  83
  84         if (!ctx)
  85                 return -ENOMEM;
  86
  87         aa_dup_task_context(ctx, cred_ctx(old));
  88         cred_ctx(new) = ctx;
  89         return 0;
  90 }
  91
  92 /*
  93  * transfer the apparmor data to a blank set of creds
  94  */
  95 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
  96 {
  97         const struct aa_task_ctx *old_ctx = cred_ctx(old);
  98         struct aa_task_ctx *new_ctx = cred_ctx(new);
  99
 100         aa_dup_task_context(new_ctx, old_ctx);
 101 }
 102
 103 static int apparmor_ptrace_access_check(struct task_struct *child,
 104                                         unsigned int mode)
 105 {
 106         return aa_ptrace(current, child, mode);
 107 }
 108
 109 static int apparmor_ptrace_traceme(struct task_struct *parent)
 110 {
 111         return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
 112 }
 113
 114 /* Derived from security/commoncap.c:cap_capget */
 115 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
 116                            kernel_cap_t *inheritable, kernel_cap_t *permitted)
 117 {
 118         struct aa_profile *profile;
 119         const struct cred *cred;
 120
 121         rcu_read_lock();
 122         cred = __task_cred(target);
 123         profile = aa_cred_profile(cred);
 124
 125         /*
 126          * cap_capget is stacked ahead of this and will
 127          * initialize effective and permitted.
 128          */
 129         if (!unconfined(profile) && !COMPLAIN_MODE(profile)) {
 130                 *effective = cap_intersect(*effective, profile->caps.allow);
 131                 *permitted = cap_intersect(*permitted, profile->caps.allow);
 132         }
 133         rcu_read_unlock();
 134
 135         return 0;
 136 }
 137
 138 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
 139                             int cap, int audit)
 140 {
 141         struct aa_profile *profile;
 142         int error = 0;
 143
 144         profile = aa_cred_profile(cred);
 145         if (!unconfined(profile))
 146                 error = aa_capable(profile, cap, audit);
 147         return error;
 148 }
 149
 150 /**
 151  * common_perm - basic common permission check wrapper fn for paths
 152  * @op: operation being checked
 153  * @path: path to check permission of  (NOT NULL)
 154  * @mask: requested permissions mask
 155  * @cond: conditional info for the permission request  (NOT NULL)
 156  *
 157  * Returns: %0 else error code if error or permission denied
 158  */
 159 static int common_perm(const char *op, const struct path *path, u32 mask,
 160                        struct path_cond *cond)
 161 {
 162         struct aa_profile *profile;
 163         int error = 0;
 164
 165         profile = __aa_current_profile();
 166         if (!unconfined(profile))
 167                 error = aa_path_perm(op, profile, path, 0, mask, cond);
 168
 169         return error;
 170 }
 171
 172 /**
 173  * common_perm_cond - common permission wrapper around inode cond
 174  * @op: operation being checked
 175  * @path: location to check (NOT NULL)
 176  * @mask: requested permissions mask
 177  *
 178  * Returns: %0 else error code if error or permission denied
 179  */
 180 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
 181 {
 182         struct path_cond cond = { d_backing_inode(path->dentry)->i_uid,
 183                                   d_backing_inode(path->dentry)->i_mode
 184         };
 185
 186         if (!path_mediated_fs(path->dentry))
 187                 return 0;
 188
 189         return common_perm(op, path, mask, &cond);
 190 }
 191
 192 /**
 193  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
 194  * @op: operation being checked
 195  * @dir: directory of the dentry  (NOT NULL)
 196  * @dentry: dentry to check  (NOT NULL)
 197  * @mask: requested permissions mask
 198  * @cond: conditional info for the permission request  (NOT NULL)
 199  *
 200  * Returns: %0 else error code if error or permission denied
 201  */
 202 static int common_perm_dir_dentry(const char *op, const struct path *dir,
 203                                   struct dentry *dentry, u32 mask,
 204                                   struct path_cond *cond)
 205 {
 206         struct path path = { .mnt = dir->mnt, .dentry = dentry };
 207
 208         return common_perm(op, &path, mask, cond);
 209 }
 210
 211 /**
 212  * common_perm_rm - common permission wrapper for operations doing rm
 213  * @op: operation being checked
 214  * @dir: directory that the dentry is in  (NOT NULL)
 215  * @dentry: dentry being rm'd  (NOT NULL)
 216  * @mask: requested permission mask
 217  *
 218  * Returns: %0 else error code if error or permission denied
 219  */
 220 static int common_perm_rm(const char *op, const struct path *dir,
 221                           struct dentry *dentry, u32 mask)
 222 {
 223         struct inode *inode = d_backing_inode(dentry);
 224         struct path_cond cond = { };
 225
 226         if (!inode || !path_mediated_fs(dentry))
 227                 return 0;
 228
 229         cond.uid = inode->i_uid;
 230         cond.mode = inode->i_mode;
 231
 232         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 233 }
 234
 235 /**
 236  * common_perm_create - common permission wrapper for operations doing create
 237  * @op: operation being checked
 238  * @dir: directory that dentry will be created in  (NOT NULL)
 239  * @dentry: dentry to create   (NOT NULL)
 240  * @mask: request permission mask
 241  * @mode: created file mode
 242  *
 243  * Returns: %0 else error code if error or permission denied
 244  */
 245 static int common_perm_create(const char *op, const struct path *dir,
 246                               struct dentry *dentry, u32 mask, umode_t mode)
 247 {
 248         struct path_cond cond = { current_fsuid(), mode };
 249
 250         if (!path_mediated_fs(dir->dentry))
 251                 return 0;
 252
 253         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 254 }
 255
 256 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
 257 {
 258         return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
 259 }
 260
 261 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
 262                                umode_t mode)
 263 {
 264         return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
 265                                   S_IFDIR);
 266 }
 267
 268 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
 269 {
 270         return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
 271 }
 272
 273 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
 274                                umode_t mode, unsigned int dev)
 275 {
 276         return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
 277 }
 278
 279 static int apparmor_path_truncate(const struct path *path)
 280 {
 281         return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE);
 282 }
 283
 284 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
 285                                  const char *old_name)
 286 {
 287         return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
 288                                   S_IFLNK);
 289 }
 290
 291 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
 292                               struct dentry *new_dentry)
 293 {
 294         struct aa_profile *profile;
 295         int error = 0;
 296
 297         if (!path_mediated_fs(old_dentry))
 298                 return 0;
 299
 300         profile = aa_current_profile();
 301         if (!unconfined(profile))
 302                 error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
 303         return error;
 304 }
 305
 306 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
 307                                 const struct path *new_dir, struct dentry *new_dentry)
 308 {
 309         struct aa_profile *profile;
 310         int error = 0;
 311
 312         if (!path_mediated_fs(old_dentry))
 313                 return 0;
 314
 315         profile = aa_current_profile();
 316         if (!unconfined(profile)) {
 317                 struct path old_path = { .mnt = old_dir->mnt,
 318                                          .dentry = old_dentry };
 319                 struct path new_path = { .mnt = new_dir->mnt,
 320                                          .dentry = new_dentry };
 321                 struct path_cond cond = { d_backing_inode(old_dentry)->i_uid,
 322                                           d_backing_inode(old_dentry)->i_mode
 323                 };
 324
 325                 error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
 326                                      MAY_READ | AA_MAY_META_READ | MAY_WRITE |
 327                                      AA_MAY_META_WRITE | AA_MAY_DELETE,
 328                                      &cond);
 329                 if (!error)
 330                         error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
 331                                              0, MAY_WRITE | AA_MAY_META_WRITE |
 332                                              AA_MAY_CREATE, &cond);
 333
 334         }
 335         return error;
 336 }
 337
 338 static int apparmor_path_chmod(const struct path *path, umode_t mode)
 339 {
 340         return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
 341 }
 342
 343 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
 344 {
 345         return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
 346 }
 347
 348 static int apparmor_inode_getattr(const struct path *path)
 349 {
 350         return common_perm_cond(OP_GETATTR, path, AA_MAY_META_READ);
 351 }
 352
 353 static int apparmor_file_open(struct file *file, const struct cred *cred)
 354 {
 355         struct aa_file_ctx *fctx = file->f_security;
 356         struct aa_profile *profile;
 357         int error = 0;
 358
 359         if (!path_mediated_fs(file->f_path.dentry))
 360                 return 0;
 361
 362         /* If in exec, permission is handled by bprm hooks.
 363          * Cache permissions granted by the previous exec check, with
 364          * implicit read and executable mmap which are required to
 365          * actually execute the image.
 366          */
 367         if (current->in_execve) {
 368                 fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
 369                 return 0;
 370         }
 371
 372         profile = aa_cred_profile(cred);
 373         if (!unconfined(profile)) {
 374                 struct inode *inode = file_inode(file);
 375                 struct path_cond cond = { inode->i_uid, inode->i_mode };
 376
 377                 error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
 378                                      aa_map_file_to_perms(file), &cond);
 379                 /* todo cache full allowed permissions set and state */
 380                 fctx->allow = aa_map_file_to_perms(file);
 381         }
 382
 383         return error;
 384 }
 385
 386 static int apparmor_file_alloc_security(struct file *file)
 387 {
 388         /* freed by apparmor_file_free_security */
 389         file->f_security = aa_alloc_file_context(GFP_KERNEL);
 390         if (!file->f_security)
 391                 return -ENOMEM;
 392         return 0;
 393
 394 }
 395
 396 static void apparmor_file_free_security(struct file *file)
 397 {
 398         struct aa_file_ctx *ctx = file->f_security;
 399
 400         aa_free_file_context(ctx);
 401 }
 402
 403 static int common_file_perm(const char *op, struct file *file, u32 mask)
 404 {
 405         struct aa_file_ctx *fctx = file->f_security;
 406         struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
 407         int error = 0;
 408
 409         AA_BUG(!fprofile);
 410
 411         if (!file->f_path.mnt ||
 412             !path_mediated_fs(file->f_path.dentry))
 413                 return 0;
 414
 415         profile = __aa_current_profile();
 416
 417         /* revalidate access, if task is unconfined, or the cached cred
 418          * doesn't match or if the request is for more permissions than
 419          * was granted.
 420          *
 421          * Note: the test for !unconfined(fprofile) is to handle file
 422          *       delegation from unconfined tasks
 423          */
 424         if (!unconfined(profile) && !unconfined(fprofile) &&
 425             ((fprofile != profile) || (mask & ~fctx->allow)))
 426                 error = aa_file_perm(op, profile, file, mask);
 427
 428         return error;
 429 }
 430
 431 static int apparmor_file_permission(struct file *file, int mask)
 432 {
 433         return common_file_perm(OP_FPERM, file, mask);
 434 }
 435
 436 static int apparmor_file_lock(struct file *file, unsigned int cmd)
 437 {
 438         u32 mask = AA_MAY_LOCK;
 439
 440         if (cmd == F_WRLCK)
 441                 mask |= MAY_WRITE;
 442
 443         return common_file_perm(OP_FLOCK, file, mask);
 444 }
 445
 446 static int common_mmap(const char *op, struct file *file, unsigned long prot,
 447                        unsigned long flags)
 448 {
 449         int mask = 0;
 450
 451         if (!file || !file->f_security)
 452                 return 0;
 453
 454         if (prot & PROT_READ)
 455                 mask |= MAY_READ;
 456         /*
 457          * Private mappings don't require write perms since they don't
 458          * write back to the files
 459          */
 460         if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
 461                 mask |= MAY_WRITE;
 462         if (prot & PROT_EXEC)
 463                 mask |= AA_EXEC_MMAP;
 464
 465         return common_file_perm(op, file, mask);
 466 }
 467
 468 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
 469                               unsigned long prot, unsigned long flags)
 470 {
 471         return common_mmap(OP_FMMAP, file, prot, flags);
 472 }
 473
 474 static int apparmor_file_mprotect(struct vm_area_struct *vma,
 475                                   unsigned long reqprot, unsigned long prot)
 476 {
 477         return common_mmap(OP_FMPROT, vma->vm_file, prot,
 478                            !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
 479 }
 480
 481 static int apparmor_getprocattr(struct task_struct *task, char *name,
 482                                 char **value)
 483 {
 484         int error = -ENOENT;
 485         /* released below */
 486         const struct cred *cred = get_task_cred(task);
 487         struct aa_task_ctx *ctx = cred_ctx(cred);
 488         struct aa_profile *profile = NULL;
 489
 490         if (strcmp(name, "current") == 0)
 491                 profile = aa_get_newest_profile(ctx->profile);
 492         else if (strcmp(name, "prev") == 0  && ctx->previous)
 493                 profile = aa_get_newest_profile(ctx->previous);
 494         else if (strcmp(name, "exec") == 0 && ctx->onexec)
 495                 profile = aa_get_newest_profile(ctx->onexec);
 496         else
 497                 error = -EINVAL;
 498
 499         if (profile)
 500                 error = aa_getprocattr(profile, value);
 501
 502         aa_put_profile(profile);
 503         put_cred(cred);
 504
 505         return error;
 506 }
 507
 508 static int apparmor_setprocattr(const char *name, void *value,
 509                                 size_t size)
 510 {
 511         char *command, *largs = NULL, *args = value;
 512         size_t arg_size;
 513         int error;
 514         DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR);
 515
 516         if (size == 0)
 517                 return -EINVAL;
 518
 519         /* AppArmor requires that the buffer must be null terminated atm */
 520         if (args[size - 1] != '\0') {
 521                 /* null terminate */
 522                 largs = args = kmalloc(size + 1, GFP_KERNEL);
 523                 if (!args)
 524                         return -ENOMEM;
 525                 memcpy(args, value, size);
 526                 args[size] = '\0';
 527         }
 528
 529         error = -EINVAL;
 530         args = strim(args);
 531         command = strsep(&args, " ");
 532         if (!args)
 533                 goto out;
 534         args = skip_spaces(args);
 535         if (!*args)
 536                 goto out;
 537
 538         arg_size = size - (args - (largs ? largs : (char *) value));
 539         if (strcmp(name, "current") == 0) {
 540                 if (strcmp(command, "changehat") == 0) {
 541                         error = aa_setprocattr_changehat(args, arg_size,
 542                                                          !AA_DO_TEST);
 543                 } else if (strcmp(command, "permhat") == 0) {
 544                         error = aa_setprocattr_changehat(args, arg_size,
 545                                                          AA_DO_TEST);
 546                 } else if (strcmp(command, "changeprofile") == 0) {
 547                         error = aa_change_profile(args, !AA_ONEXEC,
 548                                                   !AA_DO_TEST, false);
 549                 } else if (strcmp(command, "permprofile") == 0) {
 550                         error = aa_change_profile(args, !AA_ONEXEC, AA_DO_TEST,
 551                                                   false);
 552                 } else
 553                         goto fail;
 554         } else if (strcmp(name, "exec") == 0) {
 555                 if (strcmp(command, "exec") == 0)
 556                         error = aa_change_profile(args, AA_ONEXEC, !AA_DO_TEST,
 557                                                   false);
 558                 else
 559                         goto fail;
 560         } else
 561                 /* only support the "current" and "exec" process attributes */
 562                 goto fail;
 563
 564         if (!error)
 565                 error = size;
 566 out:
 567         kfree(largs);
 568         return error;
 569
 570 fail:
 571         aad(&sa)->profile = aa_current_profile();
 572         aad(&sa)->info = name;
 573         aad(&sa)->error = error = -EINVAL;
 574         aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
 575         goto out;
 576 }
 577
 578 static int apparmor_task_setrlimit(struct task_struct *task,
 579                 unsigned int resource, struct rlimit *new_rlim)
 580 {
 581         struct aa_profile *profile = __aa_current_profile();
 582         int error = 0;
 583
 584         if (!unconfined(profile))
 585                 error = aa_task_setrlimit(profile, task, resource, new_rlim);
 586
 587         return error;
 588 }
 589
 590 static struct security_hook_list apparmor_hooks[] = {
 591         LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
 592         LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
 593         LSM_HOOK_INIT(capget, apparmor_capget),
 594         LSM_HOOK_INIT(capable, apparmor_capable),
 595
 596         LSM_HOOK_INIT(path_link, apparmor_path_link),
 597         LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
 598         LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
 599         LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
 600         LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
 601         LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
 602         LSM_HOOK_INIT(path_rename, apparmor_path_rename),
 603         LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
 604         LSM_HOOK_INIT(path_chown, apparmor_path_chown),
 605         LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
 606         LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
 607
 608         LSM_HOOK_INIT(file_open, apparmor_file_open),
 609         LSM_HOOK_INIT(file_permission, apparmor_file_permission),
 610         LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
 611         LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
 612         LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
 613         LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
 614         LSM_HOOK_INIT(file_lock, apparmor_file_lock),
 615
 616         LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
 617         LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
 618
 619         LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
 620         LSM_HOOK_INIT(cred_free, apparmor_cred_free),
 621         LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
 622         LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
 623
 624         LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds),
 625         LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
 626         LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
 627         LSM_HOOK_INIT(bprm_secureexec, apparmor_bprm_secureexec),
 628
 629         LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
 630 };
 631
 632 /*
 633  * AppArmor sysfs module parameters
 634  */
 635
 636 static int param_set_aabool(const char *val, const struct kernel_param *kp);
 637 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
 638 #define param_check_aabool param_check_bool
 639 static const struct kernel_param_ops param_ops_aabool = {
 640         .flags = KERNEL_PARAM_OPS_FL_NOARG,
 641         .set = param_set_aabool,
 642         .get = param_get_aabool
 643 };
 644
 645 static int param_set_aauint(const char *val, const struct kernel_param *kp);
 646 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
 647 #define param_check_aauint param_check_uint
 648 static const struct kernel_param_ops param_ops_aauint = {
 649         .set = param_set_aauint,
 650         .get = param_get_aauint
 651 };
 652
 653 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
 654 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
 655 #define param_check_aalockpolicy param_check_bool
 656 static const struct kernel_param_ops param_ops_aalockpolicy = {
 657         .flags = KERNEL_PARAM_OPS_FL_NOARG,
 658         .set = param_set_aalockpolicy,
 659         .get = param_get_aalockpolicy
 660 };
 661
 662 static int param_set_audit(const char *val, struct kernel_param *kp);
 663 static int param_get_audit(char *buffer, struct kernel_param *kp);
 664
 665 static int param_set_mode(const char *val, struct kernel_param *kp);
 666 static int param_get_mode(char *buffer, struct kernel_param *kp);
 667
 668 /* Flag values, also controllable via /sys/module/apparmor/parameters
 669  * We define special types as we want to do additional mediation.
 670  */
 671
 672 /* AppArmor global enforcement switch - complain, enforce, kill */
 673 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
 674 module_param_call(mode, param_set_mode, param_get_mode,
 675                   &aa_g_profile_mode, S_IRUSR | S_IWUSR);
 676
 677 /* whether policy verification hashing is enabled */
 678 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
 679 #ifdef CONFIG_SECURITY_APPARMOR_HASH
 680 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
 681 #endif
 682
 683 /* Debug mode */
 684 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_DEBUG_MESSAGES);
 685 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
 686
 687 /* Audit mode */
 688 enum audit_mode aa_g_audit;
 689 module_param_call(audit, param_set_audit, param_get_audit,
 690                   &aa_g_audit, S_IRUSR | S_IWUSR);
 691
 692 /* Determines if audit header is included in audited messages.  This
 693  * provides more context if the audit daemon is not running
 694  */
 695 bool aa_g_audit_header = 1;
 696 module_param_named(audit_header, aa_g_audit_header, aabool,
 697                    S_IRUSR | S_IWUSR);
 698
 699 /* lock out loading/removal of policy
 700  * TODO: add in at boot loading of policy, which is the only way to
 701  *       load policy, if lock_policy is set
 702  */
 703 bool aa_g_lock_policy;
 704 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
 705                    S_IRUSR | S_IWUSR);
 706
 707 /* Syscall logging mode */
 708 bool aa_g_logsyscall;
 709 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
 710
 711 /* Maximum pathname length before accesses will start getting rejected */
 712 unsigned int aa_g_path_max = 2 * PATH_MAX;
 713 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
 714
 715 /* Determines how paranoid loading of policy is and how much verification
 716  * on the loaded policy is done.
 717  * DEPRECATED: read only as strict checking of load is always done now
 718  * that none root users (user namespaces) can load policy.
 719  */
 720 bool aa_g_paranoid_load = 1;
 721 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
 722
 723 /* Boot time disable flag */
 724 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
 725 module_param_named(enabled, apparmor_enabled, bool, S_IRUGO);
 726
 727 static int __init apparmor_enabled_setup(char *str)
 728 {
 729         unsigned long enabled;
 730         int error = kstrtoul(str, 0, &enabled);
 731         if (!error)
 732                 apparmor_enabled = enabled ? 1 : 0;
 733         return 1;
 734 }
 735
 736 __setup("apparmor=", apparmor_enabled_setup);
 737
 738 /* set global flag turning off the ability to load policy */
 739 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
 740 {
 741         if (!policy_admin_capable(NULL))
 742                 return -EPERM;
 743         return param_set_bool(val, kp);
 744 }
 745
 746 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
 747 {
 748         if (!policy_view_capable(NULL))
 749                 return -EPERM;
 750         if (!apparmor_enabled)
 751                 return -EINVAL;
 752         return param_get_bool(buffer, kp);
 753 }
 754
 755 static int param_set_aabool(const char *val, const struct kernel_param *kp)
 756 {
 757         if (!policy_admin_capable(NULL))
 758                 return -EPERM;
 759         if (!apparmor_enabled)
 760                 return -EINVAL;
 761         return param_set_bool(val, kp);
 762 }
 763
 764 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
 765 {
 766         if (!policy_view_capable(NULL))
 767                 return -EPERM;
 768         if (!apparmor_enabled)
 769                 return -EINVAL;
 770         return param_get_bool(buffer, kp);
 771 }
 772
 773 static int param_set_aauint(const char *val, const struct kernel_param *kp)
 774 {
 775         if (!policy_admin_capable(NULL))
 776                 return -EPERM;
 777         if (!apparmor_enabled)
 778                 return -EINVAL;
 779         return param_set_uint(val, kp);
 780 }
 781
 782 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
 783 {
 784         if (!policy_view_capable(NULL))
 785                 return -EPERM;
 786         if (!apparmor_enabled)
 787                 return -EINVAL;
 788         return param_get_uint(buffer, kp);
 789 }
 790
 791 static int param_get_audit(char *buffer, struct kernel_param *kp)
 792 {
 793         if (!policy_view_capable(NULL))
 794                 return -EPERM;
 795
 796         if (!apparmor_enabled)
 797                 return -EINVAL;
 798
 799         return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
 800 }
 801
 802 static int param_set_audit(const char *val, struct kernel_param *kp)
 803 {
 804         int i;
 805         if (!policy_admin_capable(NULL))
 806                 return -EPERM;
 807
 808         if (!apparmor_enabled)
 809                 return -EINVAL;
 810
 811         if (!val)
 812                 return -EINVAL;
 813
 814         for (i = 0; i < AUDIT_MAX_INDEX; i++) {
 815                 if (strcmp(val, audit_mode_names[i]) == 0) {
 816                         aa_g_audit = i;
 817                         return 0;
 818                 }
 819         }
 820
 821         return -EINVAL;
 822 }
 823
 824 static int param_get_mode(char *buffer, struct kernel_param *kp)
 825 {
 826         if (!policy_view_capable(NULL))
 827                 return -EPERM;
 828
 829         if (!apparmor_enabled)
 830                 return -EINVAL;
 831
 832         return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
 833 }
 834
 835 static int param_set_mode(const char *val, struct kernel_param *kp)
 836 {
 837         int i;
 838         if (!policy_admin_capable(NULL))
 839                 return -EPERM;
 840
 841         if (!apparmor_enabled)
 842                 return -EINVAL;
 843
 844         if (!val)
 845                 return -EINVAL;
 846
 847         for (i = 0; i < APPARMOR_MODE_NAMES_MAX_INDEX; i++) {
 848                 if (strcmp(val, aa_profile_mode_names[i]) == 0) {
 849                         aa_g_profile_mode = i;
 850                         return 0;
 851                 }
 852         }
 853
 854         return -EINVAL;
 855 }
 856
 857 /*
 858  * AppArmor init functions
 859  */
 860
 861 /**
 862  * set_init_ctx - set a task context and profile on the first task.
 863  *
 864  * TODO: allow setting an alternate profile than unconfined
 865  */
 866 static int __init set_init_ctx(void)
 867 {
 868         struct cred *cred = (struct cred *)current->real_cred;
 869         struct aa_task_ctx *ctx;
 870
 871         ctx = aa_alloc_task_context(GFP_KERNEL);
 872         if (!ctx)
 873                 return -ENOMEM;
 874
 875         ctx->profile = aa_get_profile(root_ns->unconfined);
 876         cred_ctx(cred) = ctx;
 877
 878         return 0;
 879 }
 880
 881 static void destroy_buffers(void)
 882 {
 883         u32 i, j;
 884
 885         for_each_possible_cpu(i) {
 886                 for_each_cpu_buffer(j) {
 887                         kfree(per_cpu(aa_buffers, i).buf[j]);
 888                         per_cpu(aa_buffers, i).buf[j] = NULL;
 889                 }
 890         }
 891 }
 892
 893 static int __init alloc_buffers(void)
 894 {
 895         u32 i, j;
 896
 897         for_each_possible_cpu(i) {
 898                 for_each_cpu_buffer(j) {
 899                         char *buffer;
 900
 901                         if (cpu_to_node(i) > num_online_nodes())
 902                                 /* fallback to kmalloc for offline nodes */
 903                                 buffer = kmalloc(aa_g_path_max, GFP_KERNEL);
 904                         else
 905                                 buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL,
 906                                                       cpu_to_node(i));
 907                         if (!buffer) {
 908                                 destroy_buffers();
 909                                 return -ENOMEM;
 910                         }
 911                         per_cpu(aa_buffers, i).buf[j] = buffer;
 912                 }
 913         }
 914
 915         return 0;
 916 }
 917
 918 #ifdef CONFIG_SYSCTL
 919 static int apparmor_dointvec(struct ctl_table *table, int write,
 920                              void __user *buffer, size_t *lenp, loff_t *ppos)
 921 {
 922         if (!policy_admin_capable(NULL))
 923                 return -EPERM;
 924         if (!apparmor_enabled)
 925                 return -EINVAL;
 926
 927         return proc_dointvec(table, write, buffer, lenp, ppos);
 928 }
 929
 930 static struct ctl_path apparmor_sysctl_path[] = {
 931         { .procname = "kernel", },
 932         { }
 933 };
 934
 935 static struct ctl_table apparmor_sysctl_table[] = {
 936         {
 937                 .procname       = "unprivileged_userns_apparmor_policy",
 938                 .data           = &unprivileged_userns_apparmor_policy,
 939                 .maxlen         = sizeof(int),
 940                 .mode           = 0600,
 941                 .proc_handler   = apparmor_dointvec,
 942         },
 943         { }
 944 };
 945
 946 static int __init apparmor_init_sysctl(void)
 947 {
 948         return register_sysctl_paths(apparmor_sysctl_path,
 949                                      apparmor_sysctl_table) ? 0 : -ENOMEM;
 950 }
 951 #else
 952 static inline int apparmor_init_sysctl(void)
 953 {
 954         return 0;
 955 }
 956 #endif /* CONFIG_SYSCTL */
 957
 958 static int __init apparmor_init(void)
 959 {
 960         int error;
 961
 962         if (!apparmor_enabled || !security_module_enable("apparmor")) {
 963                 aa_info_message("AppArmor disabled by boot time parameter");
 964                 apparmor_enabled = 0;
 965                 return 0;
 966         }
 967
 968         error = aa_setup_dfa_engine();
 969         if (error) {
 970                 AA_ERROR("Unable to setup dfa engine\n");
 971                 goto alloc_out;
 972         }
 973
 974         error = aa_alloc_root_ns();
 975         if (error) {
 976                 AA_ERROR("Unable to allocate default profile namespace\n");
 977                 goto alloc_out;
 978         }
 979
 980         error = apparmor_init_sysctl();
 981         if (error) {
 982                 AA_ERROR("Unable to register sysctls\n");
 983                 goto alloc_out;
 984
 985         }
 986
 987         error = alloc_buffers();
 988         if (error) {
 989                 AA_ERROR("Unable to allocate work buffers\n");
 990                 goto buffers_out;
 991         }
 992
 993         error = set_init_ctx();
 994         if (error) {
 995                 AA_ERROR("Failed to set context on init task\n");
 996                 aa_free_root_ns();
 997                 goto buffers_out;
 998         }
 999         security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
1000                                 "apparmor");
1001
1002         /* Report that AppArmor successfully initialized */
1003         apparmor_initialized = 1;
1004         if (aa_g_profile_mode == APPARMOR_COMPLAIN)
1005                 aa_info_message("AppArmor initialized: complain mode enabled");
1006         else if (aa_g_profile_mode == APPARMOR_KILL)
1007                 aa_info_message("AppArmor initialized: kill mode enabled");
1008         else
1009                 aa_info_message("AppArmor initialized");
1010
1011         return error;
1012
1013 buffers_out:
1014         destroy_buffers();
1015
1016 alloc_out:
1017         aa_destroy_aafs();
1018         aa_teardown_dfa_engine();
1019
1020         apparmor_enabled = 0;
1021         return error;
1022 }
1023
1024 security_initcall(apparmor_init);