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/label.h"
  38 #include "include/policy.h"
  39 #include "include/policy_ns.h"
  40 #include "include/procattr.h"
  41
  42 /* Flag indicating whether initialization completed */
  43 int apparmor_initialized;
  44
  45 DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
  46
  47
  48 /*
  49  * LSM hook functions
  50  */
  51
  52 /*
  53  * free the associated aa_task_ctx and put its labels
  54  */
  55 static void apparmor_cred_free(struct cred *cred)
  56 {
  57         aa_free_task_context(cred_ctx(cred));
  58         cred_ctx(cred) = NULL;
  59 }
  60
  61 /*
  62  * allocate the apparmor part of blank credentials
  63  */
  64 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
  65 {
  66         /* freed by apparmor_cred_free */
  67         struct aa_task_ctx *ctx = aa_alloc_task_context(gfp);
  68
  69         if (!ctx)
  70                 return -ENOMEM;
  71
  72         cred_ctx(cred) = ctx;
  73         return 0;
  74 }
  75
  76 /*
  77  * prepare new aa_task_ctx for modification by prepare_cred block
  78  */
  79 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
  80                                  gfp_t gfp)
  81 {
  82         /* freed by apparmor_cred_free */
  83         struct aa_task_ctx *ctx = aa_alloc_task_context(gfp);
  84
  85         if (!ctx)
  86                 return -ENOMEM;
  87
  88         aa_dup_task_context(ctx, cred_ctx(old));
  89         cred_ctx(new) = ctx;
  90         return 0;
  91 }
  92
  93 /*
  94  * transfer the apparmor data to a blank set of creds
  95  */
  96 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
  97 {
  98         const struct aa_task_ctx *old_ctx = cred_ctx(old);
  99         struct aa_task_ctx *new_ctx = cred_ctx(new);
 100
 101         aa_dup_task_context(new_ctx, old_ctx);
 102 }
 103
 104 static int apparmor_ptrace_access_check(struct task_struct *child,
 105                                         unsigned int mode)
 106 {
 107         struct aa_label *tracer, *tracee;
 108         int error;
 109
 110         tracer = begin_current_label_crit_section();
 111         tracee = aa_get_task_label(child);
 112         error = aa_may_ptrace(tracer, tracee,
 113                   mode == PTRACE_MODE_READ ? AA_PTRACE_READ : AA_PTRACE_TRACE);
 114         aa_put_label(tracee);
 115         end_current_label_crit_section(tracer);
 116
 117         return error;
 118 }
 119
 120 static int apparmor_ptrace_traceme(struct task_struct *parent)
 121 {
 122         struct aa_label *tracer, *tracee;
 123         int error;
 124
 125         tracee = begin_current_label_crit_section();
 126         tracer = aa_get_task_label(parent);
 127         error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE);
 128         aa_put_label(tracer);
 129         end_current_label_crit_section(tracee);
 130
 131         return error;
 132 }
 133
 134 /* Derived from security/commoncap.c:cap_capget */
 135 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
 136                            kernel_cap_t *inheritable, kernel_cap_t *permitted)
 137 {
 138         struct aa_label *label;
 139         const struct cred *cred;
 140
 141         rcu_read_lock();
 142         cred = __task_cred(target);
 143         label = aa_get_newest_cred_label(cred);
 144
 145         /*
 146          * cap_capget is stacked ahead of this and will
 147          * initialize effective and permitted.
 148          */
 149         if (!unconfined(label)) {
 150                 struct aa_profile *profile;
 151                 struct label_it i;
 152
 153                 label_for_each_confined(i, label, profile) {
 154                         if (COMPLAIN_MODE(profile))
 155                                 continue;
 156                         *effective = cap_intersect(*effective,
 157                                                    profile->caps.allow);
 158                         *permitted = cap_intersect(*permitted,
 159                                                    profile->caps.allow);
 160                 }
 161         }
 162         rcu_read_unlock();
 163         aa_put_label(label);
 164
 165         return 0;
 166 }
 167
 168 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
 169                             int cap, int audit)
 170 {
 171         struct aa_label *label;
 172         int error = 0;
 173
 174         label = aa_get_newest_cred_label(cred);
 175         if (!unconfined(label))
 176                 error = aa_capable(label, cap, audit);
 177         aa_put_label(label);
 178
 179         return error;
 180 }
 181
 182 /**
 183  * common_perm - basic common permission check wrapper fn for paths
 184  * @op: operation being checked
 185  * @path: path to check permission of  (NOT NULL)
 186  * @mask: requested permissions mask
 187  * @cond: conditional info for the permission request  (NOT NULL)
 188  *
 189  * Returns: %0 else error code if error or permission denied
 190  */
 191 static int common_perm(const char *op, const struct path *path, u32 mask,
 192                        struct path_cond *cond)
 193 {
 194         struct aa_label *label;
 195         int error = 0;
 196
 197         label = __begin_current_label_crit_section();
 198         if (!unconfined(label))
 199                 error = aa_path_perm(op, label, path, 0, mask, cond);
 200         __end_current_label_crit_section(label);
 201
 202         return error;
 203 }
 204
 205 /**
 206  * common_perm_cond - common permission wrapper around inode cond
 207  * @op: operation being checked
 208  * @path: location to check (NOT NULL)
 209  * @mask: requested permissions mask
 210  *
 211  * Returns: %0 else error code if error or permission denied
 212  */
 213 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
 214 {
 215         struct path_cond cond = { d_backing_inode(path->dentry)->i_uid,
 216                                   d_backing_inode(path->dentry)->i_mode
 217         };
 218
 219         if (!path_mediated_fs(path->dentry))
 220                 return 0;
 221
 222         return common_perm(op, path, mask, &cond);
 223 }
 224
 225 /**
 226  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
 227  * @op: operation being checked
 228  * @dir: directory of the dentry  (NOT NULL)
 229  * @dentry: dentry to check  (NOT NULL)
 230  * @mask: requested permissions mask
 231  * @cond: conditional info for the permission request  (NOT NULL)
 232  *
 233  * Returns: %0 else error code if error or permission denied
 234  */
 235 static int common_perm_dir_dentry(const char *op, const struct path *dir,
 236                                   struct dentry *dentry, u32 mask,
 237                                   struct path_cond *cond)
 238 {
 239         struct path path = { .mnt = dir->mnt, .dentry = dentry };
 240
 241         return common_perm(op, &path, mask, cond);
 242 }
 243
 244 /**
 245  * common_perm_rm - common permission wrapper for operations doing rm
 246  * @op: operation being checked
 247  * @dir: directory that the dentry is in  (NOT NULL)
 248  * @dentry: dentry being rm'd  (NOT NULL)
 249  * @mask: requested permission mask
 250  *
 251  * Returns: %0 else error code if error or permission denied
 252  */
 253 static int common_perm_rm(const char *op, const struct path *dir,
 254                           struct dentry *dentry, u32 mask)
 255 {
 256         struct inode *inode = d_backing_inode(dentry);
 257         struct path_cond cond = { };
 258
 259         if (!inode || !path_mediated_fs(dentry))
 260                 return 0;
 261
 262         cond.uid = inode->i_uid;
 263         cond.mode = inode->i_mode;
 264
 265         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 266 }
 267
 268 /**
 269  * common_perm_create - common permission wrapper for operations doing create
 270  * @op: operation being checked
 271  * @dir: directory that dentry will be created in  (NOT NULL)
 272  * @dentry: dentry to create   (NOT NULL)
 273  * @mask: request permission mask
 274  * @mode: created file mode
 275  *
 276  * Returns: %0 else error code if error or permission denied
 277  */
 278 static int common_perm_create(const char *op, const struct path *dir,
 279                               struct dentry *dentry, u32 mask, umode_t mode)
 280 {
 281         struct path_cond cond = { current_fsuid(), mode };
 282
 283         if (!path_mediated_fs(dir->dentry))
 284                 return 0;
 285
 286         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 287 }
 288
 289 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
 290 {
 291         return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
 292 }
 293
 294 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
 295                                umode_t mode)
 296 {
 297         return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
 298                                   S_IFDIR);
 299 }
 300
 301 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
 302 {
 303         return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
 304 }
 305
 306 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
 307                                umode_t mode, unsigned int dev)
 308 {
 309         return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
 310 }
 311
 312 static int apparmor_path_truncate(const struct path *path)
 313 {
 314         return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
 315 }
 316
 317 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
 318                                  const char *old_name)
 319 {
 320         return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
 321                                   S_IFLNK);
 322 }
 323
 324 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
 325                               struct dentry *new_dentry)
 326 {
 327         struct aa_label *label;
 328         int error = 0;
 329
 330         if (!path_mediated_fs(old_dentry))
 331                 return 0;
 332
 333         label = begin_current_label_crit_section();
 334         if (!unconfined(label))
 335                 error = aa_path_link(label, old_dentry, new_dir, new_dentry);
 336         end_current_label_crit_section(label);
 337
 338         return error;
 339 }
 340
 341 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
 342                                 const struct path *new_dir, struct dentry *new_dentry)
 343 {
 344         struct aa_label *label;
 345         int error = 0;
 346
 347         if (!path_mediated_fs(old_dentry))
 348                 return 0;
 349
 350         label = begin_current_label_crit_section();
 351         if (!unconfined(label)) {
 352                 struct path old_path = { .mnt = old_dir->mnt,
 353                                          .dentry = old_dentry };
 354                 struct path new_path = { .mnt = new_dir->mnt,
 355                                          .dentry = new_dentry };
 356                 struct path_cond cond = { d_backing_inode(old_dentry)->i_uid,
 357                                           d_backing_inode(old_dentry)->i_mode
 358                 };
 359
 360                 error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0,
 361                                      MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
 362                                      AA_MAY_SETATTR | AA_MAY_DELETE,
 363                                      &cond);
 364                 if (!error)
 365                         error = aa_path_perm(OP_RENAME_DEST, label, &new_path,
 366                                              0, MAY_WRITE | AA_MAY_SETATTR |
 367                                              AA_MAY_CREATE, &cond);
 368
 369         }
 370         end_current_label_crit_section(label);
 371
 372         return error;
 373 }
 374
 375 static int apparmor_path_chmod(const struct path *path, umode_t mode)
 376 {
 377         return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
 378 }
 379
 380 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
 381 {
 382         return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
 383 }
 384
 385 static int apparmor_inode_getattr(const struct path *path)
 386 {
 387         return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
 388 }
 389
 390 static int apparmor_file_open(struct file *file, const struct cred *cred)
 391 {
 392         struct aa_file_ctx *fctx = file_ctx(file);
 393         struct aa_label *label;
 394         int error = 0;
 395
 396         if (!path_mediated_fs(file->f_path.dentry))
 397                 return 0;
 398
 399         /* If in exec, permission is handled by bprm hooks.
 400          * Cache permissions granted by the previous exec check, with
 401          * implicit read and executable mmap which are required to
 402          * actually execute the image.
 403          */
 404         if (current->in_execve) {
 405                 fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
 406                 return 0;
 407         }
 408
 409         label = aa_get_newest_cred_label(cred);
 410         if (!unconfined(label)) {
 411                 struct inode *inode = file_inode(file);
 412                 struct path_cond cond = { inode->i_uid, inode->i_mode };
 413
 414                 error = aa_path_perm(OP_OPEN, label, &file->f_path, 0,
 415                                      aa_map_file_to_perms(file), &cond);
 416                 /* todo cache full allowed permissions set and state */
 417                 fctx->allow = aa_map_file_to_perms(file);
 418         }
 419         aa_put_label(label);
 420
 421         return error;
 422 }
 423
 424 static int apparmor_file_alloc_security(struct file *file)
 425 {
 426         int error = 0;
 427
 428         /* freed by apparmor_file_free_security */
 429         struct aa_label *label = begin_current_label_crit_section();
 430         file->f_security = aa_alloc_file_ctx(label, GFP_KERNEL);
 431         if (!file_ctx(file))
 432                 error = -ENOMEM;
 433         end_current_label_crit_section(label);
 434
 435         return error;
 436 }
 437
 438 static void apparmor_file_free_security(struct file *file)
 439 {
 440         aa_free_file_ctx(file_ctx(file));
 441 }
 442
 443 static int common_file_perm(const char *op, struct file *file, u32 mask)
 444 {
 445         struct aa_label *label;
 446         int error = 0;
 447
 448         /* don't reaudit files closed during inheritance */
 449         if (file->f_path.dentry == aa_null.dentry)
 450                 return -EACCES;
 451
 452         label = __begin_current_label_crit_section();
 453         error = aa_file_perm(op, label, file, mask);
 454         __end_current_label_crit_section(label);
 455
 456         return error;
 457 }
 458
 459 static int apparmor_file_receive(struct file *file)
 460 {
 461         return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file));
 462 }
 463
 464 static int apparmor_file_permission(struct file *file, int mask)
 465 {
 466         return common_file_perm(OP_FPERM, file, mask);
 467 }
 468
 469 static int apparmor_file_lock(struct file *file, unsigned int cmd)
 470 {
 471         u32 mask = AA_MAY_LOCK;
 472
 473         if (cmd == F_WRLCK)
 474                 mask |= MAY_WRITE;
 475
 476         return common_file_perm(OP_FLOCK, file, mask);
 477 }
 478
 479 static int common_mmap(const char *op, struct file *file, unsigned long prot,
 480                        unsigned long flags)
 481 {
 482         int mask = 0;
 483
 484         if (!file || !file_ctx(file))
 485                 return 0;
 486
 487         if (prot & PROT_READ)
 488                 mask |= MAY_READ;
 489         /*
 490          * Private mappings don't require write perms since they don't
 491          * write back to the files
 492          */
 493         if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
 494                 mask |= MAY_WRITE;
 495         if (prot & PROT_EXEC)
 496                 mask |= AA_EXEC_MMAP;
 497
 498         return common_file_perm(op, file, mask);
 499 }
 500
 501 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
 502                               unsigned long prot, unsigned long flags)
 503 {
 504         return common_mmap(OP_FMMAP, file, prot, flags);
 505 }
 506
 507 static int apparmor_file_mprotect(struct vm_area_struct *vma,
 508                                   unsigned long reqprot, unsigned long prot)
 509 {
 510         return common_mmap(OP_FMPROT, vma->vm_file, prot,
 511                            !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
 512 }
 513
 514 static int apparmor_getprocattr(struct task_struct *task, char *name,
 515                                 char **value)
 516 {
 517         int error = -ENOENT;
 518         /* released below */
 519         const struct cred *cred = get_task_cred(task);
 520         struct aa_task_ctx *ctx = cred_ctx(cred);
 521         struct aa_label *label = NULL;
 522
 523         if (strcmp(name, "current") == 0)
 524                 label = aa_get_newest_label(ctx->label);
 525         else if (strcmp(name, "prev") == 0  && ctx->previous)
 526                 label = aa_get_newest_label(ctx->previous);
 527         else if (strcmp(name, "exec") == 0 && ctx->onexec)
 528                 label = aa_get_newest_label(ctx->onexec);
 529         else
 530                 error = -EINVAL;
 531
 532         if (label)
 533                 error = aa_getprocattr(label, value);
 534
 535         aa_put_label(label);
 536         put_cred(cred);
 537
 538         return error;
 539 }
 540
 541 static int apparmor_setprocattr(const char *name, void *value,
 542                                 size_t size)
 543 {
 544         char *command, *largs = NULL, *args = value;
 545         size_t arg_size;
 546         int error;
 547         DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR);
 548
 549         if (size == 0)
 550                 return -EINVAL;
 551
 552         /* AppArmor requires that the buffer must be null terminated atm */
 553         if (args[size - 1] != '\0') {
 554                 /* null terminate */
 555                 largs = args = kmalloc(size + 1, GFP_KERNEL);
 556                 if (!args)
 557                         return -ENOMEM;
 558                 memcpy(args, value, size);
 559                 args[size] = '\0';
 560         }
 561
 562         error = -EINVAL;
 563         args = strim(args);
 564         command = strsep(&args, " ");
 565         if (!args)
 566                 goto out;
 567         args = skip_spaces(args);
 568         if (!*args)
 569                 goto out;
 570
 571         arg_size = size - (args - (largs ? largs : (char *) value));
 572         if (strcmp(name, "current") == 0) {
 573                 if (strcmp(command, "changehat") == 0) {
 574                         error = aa_setprocattr_changehat(args, arg_size,
 575                                                          AA_CHANGE_NOFLAGS);
 576                 } else if (strcmp(command, "permhat") == 0) {
 577                         error = aa_setprocattr_changehat(args, arg_size,
 578                                                          AA_CHANGE_TEST);
 579                 } else if (strcmp(command, "changeprofile") == 0) {
 580                         error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
 581                 } else if (strcmp(command, "permprofile") == 0) {
 582                         error = aa_change_profile(args, AA_CHANGE_TEST);
 583                 } else if (strcmp(command, "stack") == 0) {
 584                         error = aa_change_profile(args, AA_CHANGE_STACK);
 585                 } else
 586                         goto fail;
 587         } else if (strcmp(name, "exec") == 0) {
 588                 if (strcmp(command, "exec") == 0)
 589                         error = aa_change_profile(args, AA_CHANGE_ONEXEC);
 590                 else if (strcmp(command, "stack") == 0)
 591                         error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
 592                                                          AA_CHANGE_STACK));
 593                 else
 594                         goto fail;
 595         } else
 596                 /* only support the "current" and "exec" process attributes */
 597                 goto fail;
 598
 599         if (!error)
 600                 error = size;
 601 out:
 602         kfree(largs);
 603         return error;
 604
 605 fail:
 606         aad(&sa)->label = begin_current_label_crit_section();
 607         aad(&sa)->info = name;
 608         aad(&sa)->error = error = -EINVAL;
 609         aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
 610         end_current_label_crit_section(aad(&sa)->label);
 611         goto out;
 612 }
 613
 614 /**
 615  * apparmor_bprm_committing_creds - do task cleanup on committing new creds
 616  * @bprm: binprm for the exec  (NOT NULL)
 617  */
 618 static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
 619 {
 620         struct aa_label *label = aa_current_raw_label();
 621         struct aa_task_ctx *new_ctx = cred_ctx(bprm->cred);
 622
 623         /* bail out if unconfined or not changing profile */
 624         if ((new_ctx->label->proxy == label->proxy) ||
 625             (unconfined(new_ctx->label)))
 626                 return;
 627
 628         aa_inherit_files(bprm->cred, current->files);
 629
 630         current->pdeath_signal = 0;
 631
 632         /* reset soft limits and set hard limits for the new label */
 633         __aa_transition_rlimits(label, new_ctx->label);
 634 }
 635
 636 /**
 637  * apparmor_bprm_committed_cred - do cleanup after new creds committed
 638  * @bprm: binprm for the exec  (NOT NULL)
 639  */
 640 static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
 641 {
 642         /* TODO: cleanup signals - ipc mediation */
 643         return;
 644 }
 645
 646 static int apparmor_task_setrlimit(struct task_struct *task,
 647                 unsigned int resource, struct rlimit *new_rlim)
 648 {
 649         struct aa_label *label = __begin_current_label_crit_section();
 650         int error = 0;
 651
 652         if (!unconfined(label))
 653                 error = aa_task_setrlimit(label, task, resource, new_rlim);
 654         __end_current_label_crit_section(label);
 655
 656         return error;
 657 }
 658
 659 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
 660         LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
 661         LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
 662         LSM_HOOK_INIT(capget, apparmor_capget),
 663         LSM_HOOK_INIT(capable, apparmor_capable),
 664
 665         LSM_HOOK_INIT(path_link, apparmor_path_link),
 666         LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
 667         LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
 668         LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
 669         LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
 670         LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
 671         LSM_HOOK_INIT(path_rename, apparmor_path_rename),
 672         LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
 673         LSM_HOOK_INIT(path_chown, apparmor_path_chown),
 674         LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
 675         LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
 676
 677         LSM_HOOK_INIT(file_open, apparmor_file_open),
 678         LSM_HOOK_INIT(file_receive, apparmor_file_receive),
 679         LSM_HOOK_INIT(file_permission, apparmor_file_permission),
 680         LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
 681         LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
 682         LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
 683         LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
 684         LSM_HOOK_INIT(file_lock, apparmor_file_lock),
 685
 686         LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
 687         LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
 688
 689         LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
 690         LSM_HOOK_INIT(cred_free, apparmor_cred_free),
 691         LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
 692         LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
 693
 694         LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds),
 695         LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
 696         LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
 697
 698         LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
 699 };
 700
 701 /*
 702  * AppArmor sysfs module parameters
 703  */
 704
 705 static int param_set_aabool(const char *val, const struct kernel_param *kp);
 706 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
 707 #define param_check_aabool param_check_bool
 708 static const struct kernel_param_ops param_ops_aabool = {
 709         .flags = KERNEL_PARAM_OPS_FL_NOARG,
 710         .set = param_set_aabool,
 711         .get = param_get_aabool
 712 };
 713
 714 static int param_set_aauint(const char *val, const struct kernel_param *kp);
 715 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
 716 #define param_check_aauint param_check_uint
 717 static const struct kernel_param_ops param_ops_aauint = {
 718         .set = param_set_aauint,
 719         .get = param_get_aauint
 720 };
 721
 722 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
 723 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
 724 #define param_check_aalockpolicy param_check_bool
 725 static const struct kernel_param_ops param_ops_aalockpolicy = {
 726         .flags = KERNEL_PARAM_OPS_FL_NOARG,
 727         .set = param_set_aalockpolicy,
 728         .get = param_get_aalockpolicy
 729 };
 730
 731 static int param_set_audit(const char *val, struct kernel_param *kp);
 732 static int param_get_audit(char *buffer, struct kernel_param *kp);
 733
 734 static int param_set_mode(const char *val, struct kernel_param *kp);
 735 static int param_get_mode(char *buffer, struct kernel_param *kp);
 736
 737 /* Flag values, also controllable via /sys/module/apparmor/parameters
 738  * We define special types as we want to do additional mediation.
 739  */
 740
 741 /* AppArmor global enforcement switch - complain, enforce, kill */
 742 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
 743 module_param_call(mode, param_set_mode, param_get_mode,
 744                   &aa_g_profile_mode, S_IRUSR | S_IWUSR);
 745
 746 /* whether policy verification hashing is enabled */
 747 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
 748 #ifdef CONFIG_SECURITY_APPARMOR_HASH
 749 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
 750 #endif
 751
 752 /* Debug mode */
 753 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
 754 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
 755
 756 /* Audit mode */
 757 enum audit_mode aa_g_audit;
 758 module_param_call(audit, param_set_audit, param_get_audit,
 759                   &aa_g_audit, S_IRUSR | S_IWUSR);
 760
 761 /* Determines if audit header is included in audited messages.  This
 762  * provides more context if the audit daemon is not running
 763  */
 764 bool aa_g_audit_header = 1;
 765 module_param_named(audit_header, aa_g_audit_header, aabool,
 766                    S_IRUSR | S_IWUSR);
 767
 768 /* lock out loading/removal of policy
 769  * TODO: add in at boot loading of policy, which is the only way to
 770  *       load policy, if lock_policy is set
 771  */
 772 bool aa_g_lock_policy;
 773 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
 774                    S_IRUSR | S_IWUSR);
 775
 776 /* Syscall logging mode */
 777 bool aa_g_logsyscall;
 778 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
 779
 780 /* Maximum pathname length before accesses will start getting rejected */
 781 unsigned int aa_g_path_max = 2 * PATH_MAX;
 782 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR);
 783
 784 /* Determines how paranoid loading of policy is and how much verification
 785  * on the loaded policy is done.
 786  * DEPRECATED: read only as strict checking of load is always done now
 787  * that none root users (user namespaces) can load policy.
 788  */
 789 bool aa_g_paranoid_load = 1;
 790 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
 791
 792 /* Boot time disable flag */
 793 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
 794 module_param_named(enabled, apparmor_enabled, bool, S_IRUGO);
 795
 796 static int __init apparmor_enabled_setup(char *str)
 797 {
 798         unsigned long enabled;
 799         int error = kstrtoul(str, 0, &enabled);
 800         if (!error)
 801                 apparmor_enabled = enabled ? 1 : 0;
 802         return 1;
 803 }
 804
 805 __setup("apparmor=", apparmor_enabled_setup);
 806
 807 /* set global flag turning off the ability to load policy */
 808 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
 809 {
 810         if (!apparmor_enabled)
 811                 return -EINVAL;
 812         if (apparmor_initialized && !policy_admin_capable(NULL))
 813                 return -EPERM;
 814         return param_set_bool(val, kp);
 815 }
 816
 817 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
 818 {
 819         if (!apparmor_enabled)
 820                 return -EINVAL;
 821         if (apparmor_initialized && !policy_view_capable(NULL))
 822                 return -EPERM;
 823         return param_get_bool(buffer, kp);
 824 }
 825
 826 static int param_set_aabool(const char *val, const struct kernel_param *kp)
 827 {
 828         if (!apparmor_enabled)
 829                 return -EINVAL;
 830         if (apparmor_initialized && !policy_admin_capable(NULL))
 831                 return -EPERM;
 832         return param_set_bool(val, kp);
 833 }
 834
 835 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
 836 {
 837         if (!apparmor_enabled)
 838                 return -EINVAL;
 839         if (apparmor_initialized && !policy_view_capable(NULL))
 840                 return -EPERM;
 841         return param_get_bool(buffer, kp);
 842 }
 843
 844 static int param_set_aauint(const char *val, const struct kernel_param *kp)
 845 {
 846         int error;
 847
 848         if (!apparmor_enabled)
 849                 return -EINVAL;
 850         /* file is ro but enforce 2nd line check */
 851         if (apparmor_initialized)
 852                 return -EPERM;
 853
 854         error = param_set_uint(val, kp);
 855         pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
 856
 857         return error;
 858 }
 859
 860 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
 861 {
 862         if (!apparmor_enabled)
 863                 return -EINVAL;
 864         if (apparmor_initialized && !policy_view_capable(NULL))
 865                 return -EPERM;
 866         return param_get_uint(buffer, kp);
 867 }
 868
 869 static int param_get_audit(char *buffer, struct kernel_param *kp)
 870 {
 871         if (!apparmor_enabled)
 872                 return -EINVAL;
 873         if (apparmor_initialized && !policy_view_capable(NULL))
 874                 return -EPERM;
 875         return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
 876 }
 877
 878 static int param_set_audit(const char *val, struct kernel_param *kp)
 879 {
 880         int i;
 881
 882         if (!apparmor_enabled)
 883                 return -EINVAL;
 884         if (!val)
 885                 return -EINVAL;
 886         if (apparmor_initialized && !policy_admin_capable(NULL))
 887                 return -EPERM;
 888
 889         for (i = 0; i < AUDIT_MAX_INDEX; i++) {
 890                 if (strcmp(val, audit_mode_names[i]) == 0) {
 891                         aa_g_audit = i;
 892                         return 0;
 893                 }
 894         }
 895
 896         return -EINVAL;
 897 }
 898
 899 static int param_get_mode(char *buffer, struct kernel_param *kp)
 900 {
 901         if (!apparmor_enabled)
 902                 return -EINVAL;
 903         if (apparmor_initialized && !policy_view_capable(NULL))
 904                 return -EPERM;
 905
 906         return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
 907 }
 908
 909 static int param_set_mode(const char *val, struct kernel_param *kp)
 910 {
 911         int i;
 912
 913         if (!apparmor_enabled)
 914                 return -EINVAL;
 915         if (!val)
 916                 return -EINVAL;
 917         if (apparmor_initialized && !policy_admin_capable(NULL))
 918                 return -EPERM;
 919
 920         for (i = 0; i < APPARMOR_MODE_NAMES_MAX_INDEX; i++) {
 921                 if (strcmp(val, aa_profile_mode_names[i]) == 0) {
 922                         aa_g_profile_mode = i;
 923                         return 0;
 924                 }
 925         }
 926
 927         return -EINVAL;
 928 }
 929
 930 /*
 931  * AppArmor init functions
 932  */
 933
 934 /**
 935  * set_init_ctx - set a task context and profile on the first task.
 936  *
 937  * TODO: allow setting an alternate profile than unconfined
 938  */
 939 static int __init set_init_ctx(void)
 940 {
 941         struct cred *cred = (struct cred *)current->real_cred;
 942         struct aa_task_ctx *ctx;
 943
 944         ctx = aa_alloc_task_context(GFP_KERNEL);
 945         if (!ctx)
 946                 return -ENOMEM;
 947
 948         ctx->label = aa_get_label(ns_unconfined(root_ns));
 949         cred_ctx(cred) = ctx;
 950
 951         return 0;
 952 }
 953
 954 static void destroy_buffers(void)
 955 {
 956         u32 i, j;
 957
 958         for_each_possible_cpu(i) {
 959                 for_each_cpu_buffer(j) {
 960                         kfree(per_cpu(aa_buffers, i).buf[j]);
 961                         per_cpu(aa_buffers, i).buf[j] = NULL;
 962                 }
 963         }
 964 }
 965
 966 static int __init alloc_buffers(void)
 967 {
 968         u32 i, j;
 969
 970         for_each_possible_cpu(i) {
 971                 for_each_cpu_buffer(j) {
 972                         char *buffer;
 973
 974                         if (cpu_to_node(i) > num_online_nodes())
 975                                 /* fallback to kmalloc for offline nodes */
 976                                 buffer = kmalloc(aa_g_path_max, GFP_KERNEL);
 977                         else
 978                                 buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL,
 979                                                       cpu_to_node(i));
 980                         if (!buffer) {
 981                                 destroy_buffers();
 982                                 return -ENOMEM;
 983                         }
 984                         per_cpu(aa_buffers, i).buf[j] = buffer;
 985                 }
 986         }
 987
 988         return 0;
 989 }
 990
 991 #ifdef CONFIG_SYSCTL
 992 static int apparmor_dointvec(struct ctl_table *table, int write,
 993                              void __user *buffer, size_t *lenp, loff_t *ppos)
 994 {
 995         if (!policy_admin_capable(NULL))
 996                 return -EPERM;
 997         if (!apparmor_enabled)
 998                 return -EINVAL;
 999
1000         return proc_dointvec(table, write, buffer, lenp, ppos);
1001 }
1002
1003 static struct ctl_path apparmor_sysctl_path[] = {
1004         { .procname = "kernel", },
1005         { }
1006 };
1007
1008 static struct ctl_table apparmor_sysctl_table[] = {
1009         {
1010                 .procname       = "unprivileged_userns_apparmor_policy",
1011                 .data           = &unprivileged_userns_apparmor_policy,
1012                 .maxlen         = sizeof(int),
1013                 .mode           = 0600,
1014                 .proc_handler   = apparmor_dointvec,
1015         },
1016         { }
1017 };
1018
1019 static int __init apparmor_init_sysctl(void)
1020 {
1021         return register_sysctl_paths(apparmor_sysctl_path,
1022                                      apparmor_sysctl_table) ? 0 : -ENOMEM;
1023 }
1024 #else
1025 static inline int apparmor_init_sysctl(void)
1026 {
1027         return 0;
1028 }
1029 #endif /* CONFIG_SYSCTL */
1030
1031 static int __init apparmor_init(void)
1032 {
1033         int error;
1034
1035         if (!apparmor_enabled || !security_module_enable("apparmor")) {
1036                 aa_info_message("AppArmor disabled by boot time parameter");
1037                 apparmor_enabled = 0;
1038                 return 0;
1039         }
1040
1041         error = aa_setup_dfa_engine();
1042         if (error) {
1043                 AA_ERROR("Unable to setup dfa engine\n");
1044                 goto alloc_out;
1045         }
1046
1047         error = aa_alloc_root_ns();
1048         if (error) {
1049                 AA_ERROR("Unable to allocate default profile namespace\n");
1050                 goto alloc_out;
1051         }
1052
1053         error = apparmor_init_sysctl();
1054         if (error) {
1055                 AA_ERROR("Unable to register sysctls\n");
1056                 goto alloc_out;
1057
1058         }
1059
1060         error = alloc_buffers();
1061         if (error) {
1062                 AA_ERROR("Unable to allocate work buffers\n");
1063                 goto buffers_out;
1064         }
1065
1066         error = set_init_ctx();
1067         if (error) {
1068                 AA_ERROR("Failed to set context on init task\n");
1069                 aa_free_root_ns();
1070                 goto buffers_out;
1071         }
1072         security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
1073                                 "apparmor");
1074
1075         /* Report that AppArmor successfully initialized */
1076         apparmor_initialized = 1;
1077         if (aa_g_profile_mode == APPARMOR_COMPLAIN)
1078                 aa_info_message("AppArmor initialized: complain mode enabled");
1079         else if (aa_g_profile_mode == APPARMOR_KILL)
1080                 aa_info_message("AppArmor initialized: kill mode enabled");
1081         else
1082                 aa_info_message("AppArmor initialized");
1083
1084         return error;
1085
1086 buffers_out:
1087         destroy_buffers();
1088
1089 alloc_out:
1090         aa_destroy_aafs();
1091         aa_teardown_dfa_engine();
1092
1093         apparmor_enabled = 0;
1094         return error;
1095 }
1096
1097 security_initcall(apparmor_init);