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 <linux/user_namespace.h>
  26 #include <net/sock.h>
  27
  28 #include "include/apparmor.h"
  29 #include "include/apparmorfs.h"
  30 #include "include/audit.h"
  31 #include "include/capability.h"
  32 #include "include/context.h"
  33 #include "include/file.h"
  34 #include "include/ipc.h"
  35 #include "include/path.h"
  36 #include "include/policy.h"
  37 #include "include/procattr.h"
  38
  39 /* Flag indicating whether initialization completed */
  40 int apparmor_initialized __initdata;
  41
  42 /*
  43  * LSM hook functions
  44  */
  45
  46 /*
  47  * free the associated aa_task_cxt and put its profiles
  48  */
  49 static void apparmor_cred_free(struct cred *cred)
  50 {
  51         aa_free_task_context(cred_cxt(cred));
  52         cred_cxt(cred) = NULL;
  53 }
  54
  55 /*
  56  * allocate the apparmor part of blank credentials
  57  */
  58 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
  59 {
  60         /* freed by apparmor_cred_free */
  61         struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
  62         if (!cxt)
  63                 return -ENOMEM;
  64
  65         cred_cxt(cred) = cxt;
  66         return 0;
  67 }
  68
  69 /*
  70  * prepare new aa_task_cxt for modification by prepare_cred block
  71  */
  72 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
  73                                  gfp_t gfp)
  74 {
  75         /* freed by apparmor_cred_free */
  76         struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
  77         if (!cxt)
  78                 return -ENOMEM;
  79
  80         aa_dup_task_context(cxt, cred_cxt(old));
  81         cred_cxt(new) = cxt;
  82         return 0;
  83 }
  84
  85 /*
  86  * transfer the apparmor data to a blank set of creds
  87  */
  88 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
  89 {
  90         const struct aa_task_cxt *old_cxt = cred_cxt(old);
  91         struct aa_task_cxt *new_cxt = cred_cxt(new);
  92
  93         aa_dup_task_context(new_cxt, old_cxt);
  94 }
  95
  96 static int apparmor_ptrace_access_check(struct task_struct *child,
  97                                         unsigned int mode)
  98 {
  99         int error = cap_ptrace_access_check(child, mode);
 100         if (error)
 101                 return error;
 102
 103         return aa_ptrace(current, child, mode);
 104 }
 105
 106 static int apparmor_ptrace_traceme(struct task_struct *parent)
 107 {
 108         int error = cap_ptrace_traceme(parent);
 109         if (error)
 110                 return error;
 111
 112         return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
 113 }
 114
 115 /* Derived from security/commoncap.c:cap_capget */
 116 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
 117                            kernel_cap_t *inheritable, kernel_cap_t *permitted)
 118 {
 119         struct aa_profile *profile;
 120         const struct cred *cred;
 121
 122         rcu_read_lock();
 123         cred = __task_cred(target);
 124         profile = aa_cred_profile(cred);
 125
 126         *effective = cred->cap_effective;
 127         *inheritable = cred->cap_inheritable;
 128         *permitted = cred->cap_permitted;
 129
 130         if (!unconfined(profile) && !COMPLAIN_MODE(profile)) {
 131                 *effective = cap_intersect(*effective, profile->caps.allow);
 132                 *permitted = cap_intersect(*permitted, profile->caps.allow);
 133         }
 134         rcu_read_unlock();
 135
 136         return 0;
 137 }
 138
 139 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
 140                             int cap, int audit)
 141 {
 142         struct aa_profile *profile;
 143         /* cap_capable returns 0 on success, else -EPERM */
 144         int error = cap_capable(cred, ns, cap, audit);
 145         if (!error) {
 146                 profile = aa_cred_profile(cred);
 147                 if (!unconfined(profile))
 148                         error = aa_capable(profile, cap, audit);
 149         }
 150         return error;
 151 }
 152
 153 /**
 154  * common_perm - basic common permission check wrapper fn for paths
 155  * @op: operation being checked
 156  * @path: path to check permission of  (NOT NULL)
 157  * @mask: requested permissions mask
 158  * @cond: conditional info for the permission request  (NOT NULL)
 159  *
 160  * Returns: %0 else error code if error or permission denied
 161  */
 162 static int common_perm(int op, struct path *path, u32 mask,
 163                        struct path_cond *cond)
 164 {
 165         struct aa_profile *profile;
 166         int error = 0;
 167
 168         profile = __aa_current_profile();
 169         if (!unconfined(profile))
 170                 error = aa_path_perm(op, profile, path, 0, mask, cond);
 171
 172         return error;
 173 }
 174
 175 /**
 176  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
 177  * @op: operation being checked
 178  * @dir: directory of the dentry  (NOT NULL)
 179  * @dentry: dentry to check  (NOT NULL)
 180  * @mask: requested permissions mask
 181  * @cond: conditional info for the permission request  (NOT NULL)
 182  *
 183  * Returns: %0 else error code if error or permission denied
 184  */
 185 static int common_perm_dir_dentry(int op, struct path *dir,
 186                                   struct dentry *dentry, u32 mask,
 187                                   struct path_cond *cond)
 188 {
 189         struct path path = { dir->mnt, dentry };
 190
 191         return common_perm(op, &path, mask, cond);
 192 }
 193
 194 /**
 195  * common_perm_mnt_dentry - common permission wrapper when mnt, dentry
 196  * @op: operation being checked
 197  * @mnt: mount point of dentry (NOT NULL)
 198  * @dentry: dentry to check  (NOT NULL)
 199  * @mask: requested permissions mask
 200  *
 201  * Returns: %0 else error code if error or permission denied
 202  */
 203 static int common_perm_mnt_dentry(int op, struct vfsmount *mnt,
 204                                   struct dentry *dentry, u32 mask)
 205 {
 206         struct path path = { mnt, dentry };
 207         struct path_cond cond = { dentry->d_inode->i_uid,
 208                                   dentry->d_inode->i_mode
 209         };
 210
 211         return common_perm(op, &path, mask, &cond);
 212 }
 213
 214 /**
 215  * common_perm_rm - common permission wrapper for operations doing rm
 216  * @op: operation being checked
 217  * @dir: directory that the dentry is in  (NOT NULL)
 218  * @dentry: dentry being rm'd  (NOT NULL)
 219  * @mask: requested permission mask
 220  *
 221  * Returns: %0 else error code if error or permission denied
 222  */
 223 static int common_perm_rm(int op, struct path *dir,
 224                           struct dentry *dentry, u32 mask)
 225 {
 226         struct inode *inode = dentry->d_inode;
 227         struct path_cond cond = { };
 228
 229         if (!inode || !dir->mnt || !mediated_filesystem(dentry))
 230                 return 0;
 231
 232         cond.uid = inode->i_uid;
 233         cond.mode = inode->i_mode;
 234
 235         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 236 }
 237
 238 /**
 239  * common_perm_create - common permission wrapper for operations doing create
 240  * @op: operation being checked
 241  * @dir: directory that dentry will be created in  (NOT NULL)
 242  * @dentry: dentry to create   (NOT NULL)
 243  * @mask: request permission mask
 244  * @mode: created file mode
 245  *
 246  * Returns: %0 else error code if error or permission denied
 247  */
 248 static int common_perm_create(int op, struct path *dir, struct dentry *dentry,
 249                               u32 mask, umode_t mode)
 250 {
 251         struct path_cond cond = { current_fsuid(), mode };
 252
 253         if (!dir->mnt || !mediated_filesystem(dir->dentry))
 254                 return 0;
 255
 256         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 257 }
 258
 259 static int apparmor_path_unlink(struct path *dir, struct dentry *dentry)
 260 {
 261         return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
 262 }
 263
 264 static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
 265                                umode_t mode)
 266 {
 267         return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
 268                                   S_IFDIR);
 269 }
 270
 271 static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry)
 272 {
 273         return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
 274 }
 275
 276 static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
 277                                umode_t mode, unsigned int dev)
 278 {
 279         return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
 280 }
 281
 282 static int apparmor_path_truncate(struct path *path)
 283 {
 284         struct path_cond cond = { path->dentry->d_inode->i_uid,
 285                                   path->dentry->d_inode->i_mode
 286         };
 287
 288         if (!path->mnt || !mediated_filesystem(path->dentry))
 289                 return 0;
 290
 291         return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
 292                            &cond);
 293 }
 294
 295 static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
 296                                  const char *old_name)
 297 {
 298         return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
 299                                   S_IFLNK);
 300 }
 301
 302 static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
 303                               struct dentry *new_dentry)
 304 {
 305         struct aa_profile *profile;
 306         int error = 0;
 307
 308         if (!mediated_filesystem(old_dentry))
 309                 return 0;
 310
 311         profile = aa_current_profile();
 312         if (!unconfined(profile))
 313                 error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
 314         return error;
 315 }
 316
 317 static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
 318                                 struct path *new_dir, struct dentry *new_dentry)
 319 {
 320         struct aa_profile *profile;
 321         int error = 0;
 322
 323         if (!mediated_filesystem(old_dentry))
 324                 return 0;
 325
 326         profile = aa_current_profile();
 327         if (!unconfined(profile)) {
 328                 struct path old_path = { old_dir->mnt, old_dentry };
 329                 struct path new_path = { new_dir->mnt, new_dentry };
 330                 struct path_cond cond = { old_dentry->d_inode->i_uid,
 331                                           old_dentry->d_inode->i_mode
 332                 };
 333
 334                 error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
 335                                      MAY_READ | AA_MAY_META_READ | MAY_WRITE |
 336                                      AA_MAY_META_WRITE | AA_MAY_DELETE,
 337                                      &cond);
 338                 if (!error)
 339                         error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
 340                                              0, MAY_WRITE | AA_MAY_META_WRITE |
 341                                              AA_MAY_CREATE, &cond);
 342
 343         }
 344         return error;
 345 }
 346
 347 static int apparmor_path_chmod(struct path *path, umode_t mode)
 348 {
 349         if (!mediated_filesystem(path->dentry))
 350                 return 0;
 351
 352         return common_perm_mnt_dentry(OP_CHMOD, path->mnt, path->dentry, AA_MAY_CHMOD);
 353 }
 354
 355 static int apparmor_path_chown(struct path *path, kuid_t uid, kgid_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))
 362                 return 0;
 363
 364         return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
 365 }
 366
 367 static int apparmor_inode_getattr(const struct path *path)
 368 {
 369         if (!mediated_filesystem(path->dentry))
 370                 return 0;
 371
 372         return common_perm_mnt_dentry(OP_GETATTR, path->mnt, path->dentry,
 373                                       AA_MAY_META_READ);
 374 }
 375
 376 static int apparmor_file_open(struct file *file, const struct cred *cred)
 377 {
 378         struct aa_file_cxt *fcxt = file->f_security;
 379         struct aa_profile *profile;
 380         int error = 0;
 381
 382         if (!mediated_filesystem(file->f_path.dentry))
 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_inode(file);
 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))
 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         int mask = 0;
 473
 474         if (!file || !file->f_security)
 475                 return 0;
 476
 477         if (prot & PROT_READ)
 478                 mask |= MAY_READ;
 479         /*
 480          * Private mappings don't require write perms since they don't
 481          * write back to the files
 482          */
 483         if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
 484                 mask |= MAY_WRITE;
 485         if (prot & PROT_EXEC)
 486                 mask |= AA_EXEC_MMAP;
 487
 488         return common_file_perm(op, file, mask);
 489 }
 490
 491 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
 492                               unsigned long prot, unsigned long flags)
 493 {
 494         return common_mmap(OP_FMMAP, file, prot, flags);
 495 }
 496
 497 static int apparmor_file_mprotect(struct vm_area_struct *vma,
 498                                   unsigned long reqprot, unsigned long prot)
 499 {
 500         return common_mmap(OP_FMPROT, vma->vm_file, prot,
 501                            !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
 502 }
 503
 504 static int apparmor_getprocattr(struct task_struct *task, char *name,
 505                                 char **value)
 506 {
 507         int error = -ENOENT;
 508         /* released below */
 509         const struct cred *cred = get_task_cred(task);
 510         struct aa_task_cxt *cxt = cred_cxt(cred);
 511         struct aa_profile *profile = NULL;
 512
 513         if (strcmp(name, "current") == 0)
 514                 profile = aa_get_newest_profile(cxt->profile);
 515         else if (strcmp(name, "prev") == 0  && cxt->previous)
 516                 profile = aa_get_newest_profile(cxt->previous);
 517         else if (strcmp(name, "exec") == 0 && cxt->onexec)
 518                 profile = aa_get_newest_profile(cxt->onexec);
 519         else
 520                 error = -EINVAL;
 521
 522         if (profile)
 523                 error = aa_getprocattr(profile, value);
 524
 525         aa_put_profile(profile);
 526         put_cred(cred);
 527
 528         return error;
 529 }
 530
 531 static int apparmor_setprocattr(struct task_struct *task, char *name,
 532                                 void *value, size_t size)
 533 {
 534         struct common_audit_data sa;
 535         struct apparmor_audit_data aad = {0,};
 536         char *command, *args = value;
 537         size_t arg_size;
 538         int error;
 539
 540         if (size == 0)
 541                 return -EINVAL;
 542         /* args points to a PAGE_SIZE buffer, AppArmor requires that
 543          * the buffer must be null terminated or have size <= PAGE_SIZE -1
 544          * so that AppArmor can null terminate them
 545          */
 546         if (args[size - 1] != '\0') {
 547                 if (size == PAGE_SIZE)
 548                         return -EINVAL;
 549                 args[size] = '\0';
 550         }
 551
 552         /* task can only write its own attributes */
 553         if (current != task)
 554                 return -EACCES;
 555
 556         args = value;
 557         args = strim(args);
 558         command = strsep(&args, " ");
 559         if (!args)
 560                 return -EINVAL;
 561         args = skip_spaces(args);
 562         if (!*args)
 563                 return -EINVAL;
 564
 565         arg_size = size - (args - (char *) value);
 566         if (strcmp(name, "current") == 0) {
 567                 if (strcmp(command, "changehat") == 0) {
 568                         error = aa_setprocattr_changehat(args, arg_size,
 569                                                          !AA_DO_TEST);
 570                 } else if (strcmp(command, "permhat") == 0) {
 571                         error = aa_setprocattr_changehat(args, arg_size,
 572                                                          AA_DO_TEST);
 573                 } else if (strcmp(command, "changeprofile") == 0) {
 574                         error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
 575                                                              !AA_DO_TEST);
 576                 } else if (strcmp(command, "permprofile") == 0) {
 577                         error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
 578                                                              AA_DO_TEST);
 579                 } else
 580                         goto fail;
 581         } else if (strcmp(name, "exec") == 0) {
 582                 if (strcmp(command, "exec") == 0)
 583                         error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
 584                                                              !AA_DO_TEST);
 585                 else
 586                         goto fail;
 587         } else
 588                 /* only support the "current" and "exec" process attributes */
 589                 return -EINVAL;
 590
 591         if (!error)
 592                 error = size;
 593         return error;
 594
 595 fail:
 596         sa.type = LSM_AUDIT_DATA_NONE;
 597         sa.aad = &aad;
 598         aad.profile = aa_current_profile();
 599         aad.op = OP_SETPROCATTR;
 600         aad.info = name;
 601         aad.error = -EINVAL;
 602         aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
 603         return -EINVAL;
 604 }
 605
 606 static int apparmor_task_setrlimit(struct task_struct *task,
 607                 unsigned int resource, struct rlimit *new_rlim)
 608 {
 609         struct aa_profile *profile = __aa_current_profile();
 610         int error = 0;
 611
 612         if (!unconfined(profile))
 613                 error = aa_task_setrlimit(profile, task, resource, new_rlim);
 614
 615         return error;
 616 }
 617
 618 static struct security_operations apparmor_ops = {
 619         .name =                         "apparmor",
 620
 621         .ptrace_access_check =          apparmor_ptrace_access_check,
 622         .ptrace_traceme =               apparmor_ptrace_traceme,
 623         .capget =                       apparmor_capget,
 624         .capable =                      apparmor_capable,
 625
 626         .path_link =                    apparmor_path_link,
 627         .path_unlink =                  apparmor_path_unlink,
 628         .path_symlink =                 apparmor_path_symlink,
 629         .path_mkdir =                   apparmor_path_mkdir,
 630         .path_rmdir =                   apparmor_path_rmdir,
 631         .path_mknod =                   apparmor_path_mknod,
 632         .path_rename =                  apparmor_path_rename,
 633         .path_chmod =                   apparmor_path_chmod,
 634         .path_chown =                   apparmor_path_chown,
 635         .path_truncate =                apparmor_path_truncate,
 636         .inode_getattr =                apparmor_inode_getattr,
 637
 638         .file_open =                    apparmor_file_open,
 639         .file_permission =              apparmor_file_permission,
 640         .file_alloc_security =          apparmor_file_alloc_security,
 641         .file_free_security =           apparmor_file_free_security,
 642         .mmap_file =                    apparmor_mmap_file,
 643         .mmap_addr =                    cap_mmap_addr,
 644         .file_mprotect =                apparmor_file_mprotect,
 645         .file_lock =                    apparmor_file_lock,
 646
 647         .getprocattr =                  apparmor_getprocattr,
 648         .setprocattr =                  apparmor_setprocattr,
 649
 650         .cred_alloc_blank =             apparmor_cred_alloc_blank,
 651         .cred_free =                    apparmor_cred_free,
 652         .cred_prepare =                 apparmor_cred_prepare,
 653         .cred_transfer =                apparmor_cred_transfer,
 654
 655         .bprm_set_creds =               apparmor_bprm_set_creds,
 656         .bprm_committing_creds =        apparmor_bprm_committing_creds,
 657         .bprm_committed_creds =         apparmor_bprm_committed_creds,
 658         .bprm_secureexec =              apparmor_bprm_secureexec,
 659
 660         .task_setrlimit =               apparmor_task_setrlimit,
 661 };
 662
 663 /*
 664  * AppArmor sysfs module parameters
 665  */
 666
 667 static int param_set_aabool(const char *val, const struct kernel_param *kp);
 668 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
 669 #define param_check_aabool param_check_bool
 670 static struct kernel_param_ops param_ops_aabool = {
 671         .flags = KERNEL_PARAM_OPS_FL_NOARG,
 672         .set = param_set_aabool,
 673         .get = param_get_aabool
 674 };
 675
 676 static int param_set_aauint(const char *val, const struct kernel_param *kp);
 677 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
 678 #define param_check_aauint param_check_uint
 679 static struct kernel_param_ops param_ops_aauint = {
 680         .set = param_set_aauint,
 681         .get = param_get_aauint
 682 };
 683
 684 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
 685 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
 686 #define param_check_aalockpolicy param_check_bool
 687 static struct kernel_param_ops param_ops_aalockpolicy = {
 688         .flags = KERNEL_PARAM_OPS_FL_NOARG,
 689         .set = param_set_aalockpolicy,
 690         .get = param_get_aalockpolicy
 691 };
 692
 693 static int param_set_audit(const char *val, struct kernel_param *kp);
 694 static int param_get_audit(char *buffer, struct kernel_param *kp);
 695
 696 static int param_set_mode(const char *val, struct kernel_param *kp);
 697 static int param_get_mode(char *buffer, struct kernel_param *kp);
 698
 699 /* Flag values, also controllable via /sys/module/apparmor/parameters
 700  * We define special types as we want to do additional mediation.
 701  */
 702
 703 /* AppArmor global enforcement switch - complain, enforce, kill */
 704 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
 705 module_param_call(mode, param_set_mode, param_get_mode,
 706                   &aa_g_profile_mode, S_IRUSR | S_IWUSR);
 707
 708 /* Debug mode */
 709 bool aa_g_debug;
 710 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
 711
 712 /* Audit mode */
 713 enum audit_mode aa_g_audit;
 714 module_param_call(audit, param_set_audit, param_get_audit,
 715                   &aa_g_audit, S_IRUSR | S_IWUSR);
 716
 717 /* Determines if audit header is included in audited messages.  This
 718  * provides more context if the audit daemon is not running
 719  */
 720 bool aa_g_audit_header = 1;
 721 module_param_named(audit_header, aa_g_audit_header, aabool,
 722                    S_IRUSR | S_IWUSR);
 723
 724 /* lock out loading/removal of policy
 725  * TODO: add in at boot loading of policy, which is the only way to
 726  *       load policy, if lock_policy is set
 727  */
 728 bool aa_g_lock_policy;
 729 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
 730                    S_IRUSR | S_IWUSR);
 731
 732 /* Syscall logging mode */
 733 bool aa_g_logsyscall;
 734 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
 735
 736 /* Maximum pathname length before accesses will start getting rejected */
 737 unsigned int aa_g_path_max = 2 * PATH_MAX;
 738 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
 739
 740 /* Determines how paranoid loading of policy is and how much verification
 741  * on the loaded policy is done.
 742  */
 743 bool aa_g_paranoid_load = 1;
 744 module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
 745                    S_IRUSR | S_IWUSR);
 746
 747 /* Boot time disable flag */
 748 static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
 749 module_param_named(enabled, apparmor_enabled, bool, S_IRUGO);
 750
 751 static int __init apparmor_enabled_setup(char *str)
 752 {
 753         unsigned long enabled;
 754         int error = kstrtoul(str, 0, &enabled);
 755         if (!error)
 756                 apparmor_enabled = enabled ? 1 : 0;
 757         return 1;
 758 }
 759
 760 __setup("apparmor=", apparmor_enabled_setup);
 761
 762 /* set global flag turning off the ability to load policy */
 763 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
 764 {
 765         if (!capable(CAP_MAC_ADMIN))
 766                 return -EPERM;
 767         if (aa_g_lock_policy)
 768                 return -EACCES;
 769         return param_set_bool(val, kp);
 770 }
 771
 772 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
 773 {
 774         if (!capable(CAP_MAC_ADMIN))
 775                 return -EPERM;
 776         return param_get_bool(buffer, kp);
 777 }
 778
 779 static int param_set_aabool(const char *val, const struct kernel_param *kp)
 780 {
 781         if (!capable(CAP_MAC_ADMIN))
 782                 return -EPERM;
 783         return param_set_bool(val, kp);
 784 }
 785
 786 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
 787 {
 788         if (!capable(CAP_MAC_ADMIN))
 789                 return -EPERM;
 790         return param_get_bool(buffer, kp);
 791 }
 792
 793 static int param_set_aauint(const char *val, const struct kernel_param *kp)
 794 {
 795         if (!capable(CAP_MAC_ADMIN))
 796                 return -EPERM;
 797         return param_set_uint(val, kp);
 798 }
 799
 800 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
 801 {
 802         if (!capable(CAP_MAC_ADMIN))
 803                 return -EPERM;
 804         return param_get_uint(buffer, kp);
 805 }
 806
 807 static int param_get_audit(char *buffer, struct kernel_param *kp)
 808 {
 809         if (!capable(CAP_MAC_ADMIN))
 810                 return -EPERM;
 811
 812         if (!apparmor_enabled)
 813                 return -EINVAL;
 814
 815         return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
 816 }
 817
 818 static int param_set_audit(const char *val, struct kernel_param *kp)
 819 {
 820         int i;
 821         if (!capable(CAP_MAC_ADMIN))
 822                 return -EPERM;
 823
 824         if (!apparmor_enabled)
 825                 return -EINVAL;
 826
 827         if (!val)
 828                 return -EINVAL;
 829
 830         for (i = 0; i < AUDIT_MAX_INDEX; i++) {
 831                 if (strcmp(val, audit_mode_names[i]) == 0) {
 832                         aa_g_audit = i;
 833                         return 0;
 834                 }
 835         }
 836
 837         return -EINVAL;
 838 }
 839
 840 static int param_get_mode(char *buffer, struct kernel_param *kp)
 841 {
 842         if (!capable(CAP_MAC_ADMIN))
 843                 return -EPERM;
 844
 845         if (!apparmor_enabled)
 846                 return -EINVAL;
 847
 848         return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
 849 }
 850
 851 static int param_set_mode(const char *val, struct kernel_param *kp)
 852 {
 853         int i;
 854         if (!capable(CAP_MAC_ADMIN))
 855                 return -EPERM;
 856
 857         if (!apparmor_enabled)
 858                 return -EINVAL;
 859
 860         if (!val)
 861                 return -EINVAL;
 862
 863         for (i = 0; i < APPARMOR_MODE_NAMES_MAX_INDEX; i++) {
 864                 if (strcmp(val, aa_profile_mode_names[i]) == 0) {
 865                         aa_g_profile_mode = i;
 866                         return 0;
 867                 }
 868         }
 869
 870         return -EINVAL;
 871 }
 872
 873 /*
 874  * AppArmor init functions
 875  */
 876
 877 /**
 878  * set_init_cxt - set a task context and profile on the first task.
 879  *
 880  * TODO: allow setting an alternate profile than unconfined
 881  */
 882 static int __init set_init_cxt(void)
 883 {
 884         struct cred *cred = (struct cred *)current->real_cred;
 885         struct aa_task_cxt *cxt;
 886
 887         cxt = aa_alloc_task_context(GFP_KERNEL);
 888         if (!cxt)
 889                 return -ENOMEM;
 890
 891         cxt->profile = aa_get_profile(root_ns->unconfined);
 892         cred_cxt(cred) = cxt;
 893
 894         return 0;
 895 }
 896
 897 static int __init apparmor_init(void)
 898 {
 899         int error;
 900
 901         if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
 902                 aa_info_message("AppArmor disabled by boot time parameter");
 903                 apparmor_enabled = 0;
 904                 return 0;
 905         }
 906
 907         error = aa_alloc_root_ns();
 908         if (error) {
 909                 AA_ERROR("Unable to allocate default profile namespace\n");
 910                 goto alloc_out;
 911         }
 912
 913         error = set_init_cxt();
 914         if (error) {
 915                 AA_ERROR("Failed to set context on init task\n");
 916                 goto register_security_out;
 917         }
 918
 919         error = register_security(&apparmor_ops);
 920         if (error) {
 921                 struct cred *cred = (struct cred *)current->real_cred;
 922                 aa_free_task_context(cred_cxt(cred));
 923                 cred_cxt(cred) = NULL;
 924                 AA_ERROR("Unable to register AppArmor\n");
 925                 goto register_security_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 register_security_out:
 940         aa_free_root_ns();
 941
 942 alloc_out:
 943         aa_destroy_aafs();
 944
 945         apparmor_enabled = 0;
 946         return error;
 947 }
 948
 949 security_initcall(apparmor_init);