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/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 <net/sock.h>
  26
  27 #include "include/apparmor.h"
  28 #include "include/apparmorfs.h"
  29 #include "include/audit.h"
  30 #include "include/capability.h"
  31 #include "include/context.h"
  32 #include "include/file.h"
  33 #include "include/ipc.h"
  34 #include "include/path.h"
  35 #include "include/policy.h"
  36 #include "include/procattr.h"
  37
  38 /* Flag indicating whether initialization completed */
  39 int apparmor_initialized __initdata;
  40
  41 /*
  42  * LSM hook functions
  43  */
  44
  45 /*
  46  * free the associated aa_task_cxt and put its profiles
  47  */
  48 static void apparmor_cred_free(struct cred *cred)
  49 {
  50         aa_free_task_context(cred->security);
  51         cred->security = NULL;
  52 }
  53
  54 /*
  55  * allocate the apparmor part of blank credentials
  56  */
  57 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
  58 {
  59         /* freed by apparmor_cred_free */
  60         struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
  61         if (!cxt)
  62                 return -ENOMEM;
  63
  64         cred->security = cxt;
  65         return 0;
  66 }
  67
  68 /*
  69  * prepare new aa_task_cxt for modification by prepare_cred block
  70  */
  71 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
  72                                  gfp_t gfp)
  73 {
  74         /* freed by apparmor_cred_free */
  75         struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
  76         if (!cxt)
  77                 return -ENOMEM;
  78
  79         aa_dup_task_context(cxt, old->security);
  80         new->security = cxt;
  81         return 0;
  82 }
  83
  84 /*
  85  * transfer the apparmor data to a blank set of creds
  86  */
  87 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
  88 {
  89         const struct aa_task_cxt *old_cxt = old->security;
  90         struct aa_task_cxt *new_cxt = new->security;
  91
  92         aa_dup_task_context(new_cxt, old_cxt);
  93 }
  94
  95 static int apparmor_ptrace_access_check(struct task_struct *child,
  96                                         unsigned int mode)
  97 {
  98         int error = cap_ptrace_access_check(child, mode);
  99         if (error)
 100                 return error;
 101
 102         return aa_ptrace(current, child, mode);
 103 }
 104
 105 static int apparmor_ptrace_traceme(struct task_struct *parent)
 106 {
 107         int error = cap_ptrace_traceme(parent);
 108         if (error)
 109                 return error;
 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         *effective = cred->cap_effective;
 126         *inheritable = cred->cap_inheritable;
 127         *permitted = cred->cap_permitted;
 128
 129         if (!unconfined(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(struct task_struct *task, const struct cred *cred,
 139                             int cap, int audit)
 140 {
 141         struct aa_profile *profile;
 142         /* cap_capable returns 0 on success, else -EPERM */
 143         int error = cap_capable(task, cred, cap, audit);
 144         if (!error) {
 145                 profile = aa_cred_profile(cred);
 146                 if (!unconfined(profile))
 147                         error = aa_capable(task, profile, cap, audit);
 148         }
 149         return error;
 150 }
 151
 152 /**
 153  * common_perm - basic common permission check wrapper fn for paths
 154  * @op: operation being checked
 155  * @path: path to check permission of  (NOT NULL)
 156  * @mask: requested permissions mask
 157  * @cond: conditional info for the permission request  (NOT NULL)
 158  *
 159  * Returns: %0 else error code if error or permission denied
 160  */
 161 static int common_perm(int op, struct path *path, u32 mask,
 162                        struct path_cond *cond)
 163 {
 164         struct aa_profile *profile;
 165         int error = 0;
 166
 167         profile = __aa_current_profile();
 168         if (!unconfined(profile))
 169                 error = aa_path_perm(op, profile, path, 0, mask, cond);
 170
 171         return error;
 172 }
 173
 174 /**
 175  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
 176  * @op: operation being checked
 177  * @dir: directory of the dentry  (NOT NULL)
 178  * @dentry: dentry to check  (NOT NULL)
 179  * @mask: requested permissions mask
 180  * @cond: conditional info for the permission request  (NOT NULL)
 181  *
 182  * Returns: %0 else error code if error or permission denied
 183  */
 184 static int common_perm_dir_dentry(int op, struct path *dir,
 185                                   struct dentry *dentry, u32 mask,
 186                                   struct path_cond *cond)
 187 {
 188         struct path path = { dir->mnt, dentry };
 189
 190         return common_perm(op, &path, mask, cond);
 191 }
 192
 193 /**
 194  * common_perm_mnt_dentry - common permission wrapper when mnt, dentry
 195  * @op: operation being checked
 196  * @mnt: mount point of dentry (NOT NULL)
 197  * @dentry: dentry to check  (NOT NULL)
 198  * @mask: requested permissions mask
 199  *
 200  * Returns: %0 else error code if error or permission denied
 201  */
 202 static int common_perm_mnt_dentry(int op, struct vfsmount *mnt,
 203                                   struct dentry *dentry, u32 mask)
 204 {
 205         struct path path = { mnt, dentry };
 206         struct path_cond cond = { dentry->d_inode->i_uid,
 207                                   dentry->d_inode->i_mode
 208         };
 209
 210         return common_perm(op, &path, mask, &cond);
 211 }
 212
 213 /**
 214  * common_perm_rm - common permission wrapper for operations doing rm
 215  * @op: operation being checked
 216  * @dir: directory that the dentry is in  (NOT NULL)
 217  * @dentry: dentry being rm'd  (NOT NULL)
 218  * @mask: requested permission mask
 219  *
 220  * Returns: %0 else error code if error or permission denied
 221  */
 222 static int common_perm_rm(int op, struct path *dir,
 223                           struct dentry *dentry, u32 mask)
 224 {
 225         struct inode *inode = dentry->d_inode;
 226         struct path_cond cond = { };
 227
 228         if (!inode || !dir->mnt || !mediated_filesystem(inode))
 229                 return 0;
 230
 231         cond.uid = inode->i_uid;
 232         cond.mode = inode->i_mode;
 233
 234         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 235 }
 236
 237 /**
 238  * common_perm_create - common permission wrapper for operations doing create
 239  * @op: operation being checked
 240  * @dir: directory that dentry will be created in  (NOT NULL)
 241  * @dentry: dentry to create   (NOT NULL)
 242  * @mask: request permission mask
 243  * @mode: created file mode
 244  *
 245  * Returns: %0 else error code if error or permission denied
 246  */
 247 static int common_perm_create(int op, struct path *dir, struct dentry *dentry,
 248                               u32 mask, umode_t mode)
 249 {
 250         struct path_cond cond = { current_fsuid(), mode };
 251
 252         if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode))
 253                 return 0;
 254
 255         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 256 }
 257
 258 static int apparmor_path_unlink(struct path *dir, struct dentry *dentry)
 259 {
 260         return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
 261 }
 262
 263 static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
 264                                int mode)
 265 {
 266         return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
 267                                   S_IFDIR);
 268 }
 269
 270 static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry)
 271 {
 272         return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
 273 }
 274
 275 static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
 276                                int mode, unsigned int dev)
 277 {
 278         return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
 279 }
 280
 281 static int apparmor_path_truncate(struct path *path)
 282 {
 283         struct path_cond cond = { path->dentry->d_inode->i_uid,
 284                                   path->dentry->d_inode->i_mode
 285         };
 286
 287         if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
 288                 return 0;
 289
 290         return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
 291                            &cond);
 292 }
 293
 294 static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
 295                                  const char *old_name)
 296 {
 297         return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
 298                                   S_IFLNK);
 299 }
 300
 301 static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
 302                               struct dentry *new_dentry)
 303 {
 304         struct aa_profile *profile;
 305         int error = 0;
 306
 307         if (!mediated_filesystem(old_dentry->d_inode))
 308                 return 0;
 309
 310         profile = aa_current_profile();
 311         if (!unconfined(profile))
 312                 error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
 313         return error;
 314 }
 315
 316 static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
 317                                 struct path *new_dir, struct dentry *new_dentry)
 318 {
 319         struct aa_profile *profile;
 320         int error = 0;
 321
 322         if (!mediated_filesystem(old_dentry->d_inode))
 323                 return 0;
 324
 325         profile = aa_current_profile();
 326         if (!unconfined(profile)) {
 327                 struct path old_path = { old_dir->mnt, old_dentry };
 328                 struct path new_path = { new_dir->mnt, new_dentry };
 329                 struct path_cond cond = { old_dentry->d_inode->i_uid,
 330                                           old_dentry->d_inode->i_mode
 331                 };
 332
 333                 error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
 334                                      MAY_READ | AA_MAY_META_READ | MAY_WRITE |
 335                                      AA_MAY_META_WRITE | AA_MAY_DELETE,
 336                                      &cond);
 337                 if (!error)
 338                         error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
 339                                              0, MAY_WRITE | AA_MAY_META_WRITE |
 340                                              AA_MAY_CREATE, &cond);
 341
 342         }
 343         return error;
 344 }
 345
 346 static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
 347                                mode_t mode)
 348 {
 349         if (!mediated_filesystem(dentry->d_inode))
 350                 return 0;
 351
 352         return common_perm_mnt_dentry(OP_CHMOD, mnt, dentry, AA_MAY_CHMOD);
 353 }
 354
 355 static 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
 367 static 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
 376 static int apparmor_dentry_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
 409 static 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
 419 static 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
 426 static 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
 454 static int apparmor_file_permission(struct file *file, int mask)
 455 {
 456         return common_file_perm(OP_FPERM, file, mask);
 457 }
 458
 459 static 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
 469 static 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
 493 static int apparmor_file_mmap(struct file *file, unsigned long reqprot,
 494                               unsigned long prot, unsigned long flags,
 495                               unsigned long addr, unsigned long addr_only)
 496 {
 497         int rc = 0;
 498
 499         /* do DAC check */
 500         rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
 501         if (rc || addr_only)
 502                 return rc;
 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         struct aa_profile *profile;
 519         /* released below */
 520         const struct cred *cred = get_task_cred(task);
 521         struct aa_task_cxt *cxt = cred->security;
 522         profile = aa_cred_profile(cred);
 523
 524         if (strcmp(name, "current") == 0)
 525                 error = aa_getprocattr(aa_newest_version(cxt->profile),
 526                                        value);
 527         else if (strcmp(name, "prev") == 0  && cxt->previous)
 528                 error = aa_getprocattr(aa_newest_version(cxt->previous),
 529                                        value);
 530         else if (strcmp(name, "exec") == 0 && cxt->onexec)
 531                 error = aa_getprocattr(aa_newest_version(cxt->onexec),
 532                                        value);
 533         else
 534                 error = -EINVAL;
 535
 536         put_cred(cred);
 537
 538         return error;
 539 }
 540
 541 static int apparmor_setprocattr(struct task_struct *task, char *name,
 542                                 void *value, size_t size)
 543 {
 544         char *command, *args = value;
 545         size_t arg_size;
 546         int error;
 547
 548         if (size == 0)
 549                 return -EINVAL;
 550         /* args points to a PAGE_SIZE buffer, AppArmor requires that
 551          * the buffer must be null terminated or have size <= PAGE_SIZE -1
 552          * so that AppArmor can null terminate them
 553          */
 554         if (args[size - 1] != '\0') {
 555                 if (size == PAGE_SIZE)
 556                         return -EINVAL;
 557                 args[size] = '\0';
 558         }
 559
 560         /* task can only write its own attributes */
 561         if (current != task)
 562                 return -EACCES;
 563
 564         args = value;
 565         args = strim(args);
 566         command = strsep(&args, " ");
 567         if (!args)
 568                 return -EINVAL;
 569         args = skip_spaces(args);
 570         if (!*args)
 571                 return -EINVAL;
 572
 573         arg_size = size - (args - (char *) value);
 574         if (strcmp(name, "current") == 0) {
 575                 if (strcmp(command, "changehat") == 0) {
 576                         error = aa_setprocattr_changehat(args, arg_size,
 577                                                          !AA_DO_TEST);
 578                 } else if (strcmp(command, "permhat") == 0) {
 579                         error = aa_setprocattr_changehat(args, arg_size,
 580                                                          AA_DO_TEST);
 581                 } else if (strcmp(command, "changeprofile") == 0) {
 582                         error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
 583                                                              !AA_DO_TEST);
 584                 } else if (strcmp(command, "permprofile") == 0) {
 585                         error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
 586                                                              AA_DO_TEST);
 587                 } else if (strcmp(command, "permipc") == 0) {
 588                         error = aa_setprocattr_permipc(args);
 589                 } else {
 590                         struct common_audit_data sa;
 591                         COMMON_AUDIT_DATA_INIT(&sa, NONE);
 592                         sa.aad.op = OP_SETPROCATTR;
 593                         sa.aad.info = name;
 594                         sa.aad.error = -EINVAL;
 595                         return aa_audit(AUDIT_APPARMOR_DENIED, NULL, GFP_KERNEL,
 596                                         &sa, NULL);
 597                 }
 598         } else if (strcmp(name, "exec") == 0) {
 599                 error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
 600                                                      !AA_DO_TEST);
 601         } else {
 602                 /* only support the "current" and "exec" process attributes */
 603                 return -EINVAL;
 604         }
 605         if (!error)
 606                 error = size;
 607         return error;
 608 }
 609
 610 static int apparmor_task_setrlimit(struct task_struct *task,
 611                 unsigned int resource, struct rlimit *new_rlim)
 612 {
 613         struct aa_profile *profile = aa_current_profile();
 614         int error = 0;
 615
 616         if (!unconfined(profile))
 617                 error = aa_task_setrlimit(profile, task, resource, new_rlim);
 618
 619         return error;
 620 }
 621
 622 static struct security_operations apparmor_ops = {
 623         .name =                         "apparmor",
 624
 625         .ptrace_access_check =          apparmor_ptrace_access_check,
 626         .ptrace_traceme =               apparmor_ptrace_traceme,
 627         .capget =                       apparmor_capget,
 628         .capable =                      apparmor_capable,
 629
 630         .path_link =                    apparmor_path_link,
 631         .path_unlink =                  apparmor_path_unlink,
 632         .path_symlink =                 apparmor_path_symlink,
 633         .path_mkdir =                   apparmor_path_mkdir,
 634         .path_rmdir =                   apparmor_path_rmdir,
 635         .path_mknod =                   apparmor_path_mknod,
 636         .path_rename =                  apparmor_path_rename,
 637         .path_chmod =                   apparmor_path_chmod,
 638         .path_chown =                   apparmor_path_chown,
 639         .path_truncate =                apparmor_path_truncate,
 640         .dentry_open =                  apparmor_dentry_open,
 641         .inode_getattr =                apparmor_inode_getattr,
 642
 643         .file_permission =              apparmor_file_permission,
 644         .file_alloc_security =          apparmor_file_alloc_security,
 645         .file_free_security =           apparmor_file_free_security,
 646         .file_mmap =                    apparmor_file_mmap,
 647         .file_mprotect =                apparmor_file_mprotect,
 648         .file_lock =                    apparmor_file_lock,
 649
 650         .getprocattr =                  apparmor_getprocattr,
 651         .setprocattr =                  apparmor_setprocattr,
 652
 653         .cred_alloc_blank =             apparmor_cred_alloc_blank,
 654         .cred_free =                    apparmor_cred_free,
 655         .cred_prepare =                 apparmor_cred_prepare,
 656         .cred_transfer =                apparmor_cred_transfer,
 657
 658         .bprm_set_creds =               apparmor_bprm_set_creds,
 659         .bprm_committing_creds =        apparmor_bprm_committing_creds,
 660         .bprm_committed_creds =         apparmor_bprm_committed_creds,
 661         .bprm_secureexec =              apparmor_bprm_secureexec,
 662
 663         .task_setrlimit =               apparmor_task_setrlimit,
 664 };
 665
 666 /*
 667  * AppArmor sysfs module parameters
 668  */
 669
 670 static int param_set_aabool(const char *val, const struct kernel_param *kp);
 671 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
 672 #define param_check_aabool(name, p) __param_check(name, p, int)
 673 static struct kernel_param_ops param_ops_aabool = {
 674         .set = param_set_aabool,
 675         .get = param_get_aabool
 676 };
 677
 678 static int param_set_aauint(const char *val, const struct kernel_param *kp);
 679 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
 680 #define param_check_aauint(name, p) __param_check(name, p, int)
 681 static struct kernel_param_ops param_ops_aauint = {
 682         .set = param_set_aauint,
 683         .get = param_get_aauint
 684 };
 685
 686 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
 687 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
 688 #define param_check_aalockpolicy(name, p) __param_check(name, p, int)
 689 static struct kernel_param_ops param_ops_aalockpolicy = {
 690         .set = param_set_aalockpolicy,
 691         .get = param_get_aalockpolicy
 692 };
 693
 694 static int param_set_audit(const char *val, struct kernel_param *kp);
 695 static int param_get_audit(char *buffer, struct kernel_param *kp);
 696 #define param_check_audit(name, p) __param_check(name, p, int)
 697
 698 static int param_set_mode(const char *val, struct kernel_param *kp);
 699 static int param_get_mode(char *buffer, struct kernel_param *kp);
 700 #define param_check_mode(name, p) __param_check(name, p, int)
 701
 702 /* Flag values, also controllable via /sys/module/apparmor/parameters
 703  * We define special types as we want to do additional mediation.
 704  */
 705
 706 /* AppArmor global enforcement switch - complain, enforce, kill */
 707 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
 708 module_param_call(mode, param_set_mode, param_get_mode,
 709                   &aa_g_profile_mode, S_IRUSR | S_IWUSR);
 710
 711 /* Debug mode */
 712 int aa_g_debug;
 713 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
 714
 715 /* Audit mode */
 716 enum audit_mode aa_g_audit;
 717 module_param_call(audit, param_set_audit, param_get_audit,
 718                   &aa_g_audit, S_IRUSR | S_IWUSR);
 719
 720 /* Determines if audit header is included in audited messages.  This
 721  * provides more context if the audit daemon is not running
 722  */
 723 int aa_g_audit_header = 1;
 724 module_param_named(audit_header, aa_g_audit_header, aabool,
 725                    S_IRUSR | S_IWUSR);
 726
 727 /* lock out loading/removal of policy
 728  * TODO: add in at boot loading of policy, which is the only way to
 729  *       load policy, if lock_policy is set
 730  */
 731 int aa_g_lock_policy;
 732 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
 733                    S_IRUSR | S_IWUSR);
 734
 735 /* Syscall logging mode */
 736 int aa_g_logsyscall;
 737 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
 738
 739 /* Maximum pathname length before accesses will start getting rejected */
 740 unsigned int aa_g_path_max = 2 * PATH_MAX;
 741 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
 742
 743 /* Determines how paranoid loading of policy is and how much verification
 744  * on the loaded policy is done.
 745  */
 746 int aa_g_paranoid_load = 1;
 747 module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
 748                    S_IRUSR | S_IWUSR);
 749
 750 /* Boot time disable flag */
 751 static unsigned int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
 752 module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);
 753
 754 static int __init apparmor_enabled_setup(char *str)
 755 {
 756         unsigned long enabled;
 757         int error = strict_strtoul(str, 0, &enabled);
 758         if (!error)
 759                 apparmor_enabled = enabled ? 1 : 0;
 760         return 1;
 761 }
 762
 763 __setup("apparmor=", apparmor_enabled_setup);
 764
 765 /* set global flag turning off the ability to load policy */
 766 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
 767 {
 768         if (!capable(CAP_MAC_ADMIN))
 769                 return -EPERM;
 770         if (aa_g_lock_policy)
 771                 return -EACCES;
 772         return param_set_bool(val, kp);
 773 }
 774
 775 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
 776 {
 777         if (!capable(CAP_MAC_ADMIN))
 778                 return -EPERM;
 779         return param_get_bool(buffer, kp);
 780 }
 781
 782 static int param_set_aabool(const char *val, const struct kernel_param *kp)
 783 {
 784         if (!capable(CAP_MAC_ADMIN))
 785                 return -EPERM;
 786         return param_set_bool(val, kp);
 787 }
 788
 789 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
 790 {
 791         if (!capable(CAP_MAC_ADMIN))
 792                 return -EPERM;
 793         return param_get_bool(buffer, kp);
 794 }
 795
 796 static int param_set_aauint(const char *val, const struct kernel_param *kp)
 797 {
 798         if (!capable(CAP_MAC_ADMIN))
 799                 return -EPERM;
 800         return param_set_uint(val, kp);
 801 }
 802
 803 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
 804 {
 805         if (!capable(CAP_MAC_ADMIN))
 806                 return -EPERM;
 807         return param_get_uint(buffer, kp);
 808 }
 809
 810 static int param_get_audit(char *buffer, struct kernel_param *kp)
 811 {
 812         if (!capable(CAP_MAC_ADMIN))
 813                 return -EPERM;
 814
 815         if (!apparmor_enabled)
 816                 return -EINVAL;
 817
 818         return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
 819 }
 820
 821 static int param_set_audit(const char *val, struct kernel_param *kp)
 822 {
 823         int i;
 824         if (!capable(CAP_MAC_ADMIN))
 825                 return -EPERM;
 826
 827         if (!apparmor_enabled)
 828                 return -EINVAL;
 829
 830         if (!val)
 831                 return -EINVAL;
 832
 833         for (i = 0; i < AUDIT_MAX_INDEX; i++) {
 834                 if (strcmp(val, audit_mode_names[i]) == 0) {
 835                         aa_g_audit = i;
 836                         return 0;
 837                 }
 838         }
 839
 840         return -EINVAL;
 841 }
 842
 843 static int param_get_mode(char *buffer, struct kernel_param *kp)
 844 {
 845         if (!capable(CAP_MAC_ADMIN))
 846                 return -EPERM;
 847
 848         if (!apparmor_enabled)
 849                 return -EINVAL;
 850
 851         return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
 852 }
 853
 854 static int param_set_mode(const char *val, struct kernel_param *kp)
 855 {
 856         int i;
 857         if (!capable(CAP_MAC_ADMIN))
 858                 return -EPERM;
 859
 860         if (!apparmor_enabled)
 861                 return -EINVAL;
 862
 863         if (!val)
 864                 return -EINVAL;
 865
 866         for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
 867                 if (strcmp(val, profile_mode_names[i]) == 0) {
 868                         aa_g_profile_mode = i;
 869                         return 0;
 870                 }
 871         }
 872
 873         return -EINVAL;
 874 }
 875
 876 /*
 877  * AppArmor init functions
 878  */
 879
 880 /**
 881  * set_init_cxt - set a task context and profile on the first task.
 882  *
 883  * TODO: allow setting an alternate profile than unconfined
 884  */
 885 static int __init set_init_cxt(void)
 886 {
 887         struct cred *cred = (struct cred *)current->real_cred;
 888         struct aa_task_cxt *cxt;
 889
 890         cxt = aa_alloc_task_context(GFP_KERNEL);
 891         if (!cxt)
 892                 return -ENOMEM;
 893
 894         cxt->profile = aa_get_profile(root_ns->unconfined);
 895         cred->security = cxt;
 896
 897         return 0;
 898 }
 899
 900 static int __init apparmor_init(void)
 901 {
 902         int error;
 903
 904         if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
 905                 aa_info_message("AppArmor disabled by boot time parameter");
 906                 apparmor_enabled = 0;
 907                 return 0;
 908         }
 909
 910         error = aa_alloc_root_ns();
 911         if (error) {
 912                 AA_ERROR("Unable to allocate default profile namespace\n");
 913                 goto alloc_out;
 914         }
 915
 916         error = set_init_cxt();
 917         if (error) {
 918                 AA_ERROR("Failed to set context on init task\n");
 919                 goto register_security_out;
 920         }
 921
 922         error = register_security(&apparmor_ops);
 923         if (error) {
 924                 AA_ERROR("Unable to register AppArmor\n");
 925                 goto set_init_cxt_out;
 926         }
 927
 928         /* Report that AppArmor successfully initialized */
 929         apparmor_initialized = 1;
 930         if (aa_g_profile_mode == APPARMOR_COMPLAIN)
 931                 aa_info_message("AppArmor initialized: complain mode enabled");
 932         else if (aa_g_profile_mode == APPARMOR_KILL)
 933                 aa_info_message("AppArmor initialized: kill mode enabled");
 934         else
 935                 aa_info_message("AppArmor initialized");
 936
 937         return error;
 938
 939 set_init_cxt_out:
 940         aa_free_task_context(current->real_cred->security);
 941
 942 register_security_out:
 943         aa_free_root_ns();
 944
 945 alloc_out:
 946         aa_destroy_aafs();
 947
 948         apparmor_enabled = 0;
 949         return error;
 950 }
 951
 952 security_initcall(apparmor_init);