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->security);
  52         cred->security = 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->security = 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, old->security);
  81         new->security = 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 = old->security;
  91         struct aa_task_cxt *new_cxt = new->security;
  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)) {
 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(struct task_struct *task, const struct cred *cred,
 140                             struct user_namespace *ns, int cap, int audit)
 141 {
 142         struct aa_profile *profile;
 143         /* cap_capable returns 0 on success, else -EPERM */
 144         int error = cap_capable(task, cred, ns, cap, audit);
 145         if (!error) {
 146                 profile = aa_cred_profile(cred);
 147                 if (!unconfined(profile))
 148                         error = aa_capable(task, 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(inode))
 230                 return 0;
 231
 232         cond.uid = inode->i_uid;
 233         cond.mode = inode->i_mode;
 234
 235         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
 236 }
 237
 238 /**
 239  * common_perm_create - common permission wrapper for operations doing create
 240  * @op: operation being checked
 241  * @dir: directory that dentry will be created in  (NOT NULL)
 242  * @dentry: dentry to create   (NOT NULL)
 243  * @mask: request permission mask
 244  * @mode: created file mode
 245  *
 246  * Returns: %0 else error code if error or permission denied
 247  */
 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->d_inode))
 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                                int 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                                int 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->d_inode))
 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->d_inode))
 309                 return 0;
 310
 311         profile = aa_current_profile();
 312         if (!unconfined(profile))
 313                 error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
 314         return error;
 315 }
 316
 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->d_inode))
 324                 return 0;
 325
 326         profile = aa_current_profile();
 327         if (!unconfined(profile)) {
 328                 struct path old_path = { old_dir->mnt, old_dentry };
 329                 struct path new_path = { new_dir->mnt, new_dentry };
 330                 struct path_cond cond = { old_dentry->d_inode->i_uid,
 331                                           old_dentry->d_inode->i_mode
 332                 };
 333
 334                 error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
 335                                      MAY_READ | AA_MAY_META_READ | MAY_WRITE |
 336                                      AA_MAY_META_WRITE | AA_MAY_DELETE,
 337                                      &cond);
 338                 if (!error)
 339                         error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
 340                                              0, MAY_WRITE | AA_MAY_META_WRITE |
 341                                              AA_MAY_CREATE, &cond);
 342
 343         }
 344         return error;
 345 }
 346
 347 static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
 348                                mode_t mode)
 349 {
 350         if (!mediated_filesystem(dentry->d_inode))
 351                 return 0;
 352
 353         return common_perm_mnt_dentry(OP_CHMOD, mnt, dentry, AA_MAY_CHMOD);
 354 }
 355
 356 static int apparmor_path_chown(struct path *path, uid_t uid, gid_t gid)
 357 {
 358         struct path_cond cond =  { path->dentry->d_inode->i_uid,
 359                                    path->dentry->d_inode->i_mode
 360         };
 361
 362         if (!mediated_filesystem(path->dentry->d_inode))
 363                 return 0;
 364
 365         return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
 366 }
 367
 368 static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 369 {
 370         if (!mediated_filesystem(dentry->d_inode))
 371                 return 0;
 372
 373         return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry,
 374                                       AA_MAY_META_READ);
 375 }
 376
 377 static int apparmor_dentry_open(struct file *file, const struct cred *cred)
 378 {
 379         struct aa_file_cxt *fcxt = file->f_security;
 380         struct aa_profile *profile;
 381         int error = 0;
 382
 383         if (!mediated_filesystem(file->f_path.dentry->d_inode))
 384                 return 0;
 385
 386         /* If in exec, permission is handled by bprm hooks.
 387          * Cache permissions granted by the previous exec check, with
 388          * implicit read and executable mmap which are required to
 389          * actually execute the image.
 390          */
 391         if (current->in_execve) {
 392                 fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
 393                 return 0;
 394         }
 395
 396         profile = aa_cred_profile(cred);
 397         if (!unconfined(profile)) {
 398                 struct inode *inode = file->f_path.dentry->d_inode;
 399                 struct path_cond cond = { inode->i_uid, inode->i_mode };
 400
 401                 error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
 402                                      aa_map_file_to_perms(file), &cond);
 403                 /* todo cache full allowed permissions set and state */
 404                 fcxt->allow = aa_map_file_to_perms(file);
 405         }
 406
 407         return error;
 408 }
 409
 410 static int apparmor_file_alloc_security(struct file *file)
 411 {
 412         /* freed by apparmor_file_free_security */
 413         file->f_security = aa_alloc_file_context(GFP_KERNEL);
 414         if (!file->f_security)
 415                 return -ENOMEM;
 416         return 0;
 417
 418 }
 419
 420 static void apparmor_file_free_security(struct file *file)
 421 {
 422         struct aa_file_cxt *cxt = file->f_security;
 423
 424         aa_free_file_context(cxt);
 425 }
 426
 427 static int common_file_perm(int op, struct file *file, u32 mask)
 428 {
 429         struct aa_file_cxt *fcxt = file->f_security;
 430         struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
 431         int error = 0;
 432
 433         BUG_ON(!fprofile);
 434
 435         if (!file->f_path.mnt ||
 436             !mediated_filesystem(file->f_path.dentry->d_inode))
 437                 return 0;
 438
 439         profile = __aa_current_profile();
 440
 441         /* revalidate access, if task is unconfined, or the cached cred
 442          * doesn't match or if the request is for more permissions than
 443          * was granted.
 444          *
 445          * Note: the test for !unconfined(fprofile) is to handle file
 446          *       delegation from unconfined tasks
 447          */
 448         if (!unconfined(profile) && !unconfined(fprofile) &&
 449             ((fprofile != profile) || (mask & ~fcxt->allow)))
 450                 error = aa_file_perm(op, profile, file, mask);
 451
 452         return error;
 453 }
 454
 455 static int apparmor_file_permission(struct file *file, int mask)
 456 {
 457         return common_file_perm(OP_FPERM, file, mask);
 458 }
 459
 460 static int apparmor_file_lock(struct file *file, unsigned int cmd)
 461 {
 462         u32 mask = AA_MAY_LOCK;
 463
 464         if (cmd == F_WRLCK)
 465                 mask |= MAY_WRITE;
 466
 467         return common_file_perm(OP_FLOCK, file, mask);
 468 }
 469
 470 static int common_mmap(int op, struct file *file, unsigned long prot,
 471                        unsigned long flags)
 472 {
 473         struct dentry *dentry;
 474         int mask = 0;
 475
 476         if (!file || !file->f_security)
 477                 return 0;
 478
 479         if (prot & PROT_READ)
 480                 mask |= MAY_READ;
 481         /*
 482          * Private mappings don't require write perms since they don't
 483          * write back to the files
 484          */
 485         if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
 486                 mask |= MAY_WRITE;
 487         if (prot & PROT_EXEC)
 488                 mask |= AA_EXEC_MMAP;
 489
 490         dentry = file->f_path.dentry;
 491         return common_file_perm(op, file, mask);
 492 }
 493
 494 static int apparmor_file_mmap(struct file *file, unsigned long reqprot,
 495                               unsigned long prot, unsigned long flags,
 496                               unsigned long addr, unsigned long addr_only)
 497 {
 498         int rc = 0;
 499
 500         /* do DAC check */
 501         rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
 502         if (rc || addr_only)
 503                 return rc;
 504
 505         return common_mmap(OP_FMMAP, file, prot, flags);
 506 }
 507
 508 static int apparmor_file_mprotect(struct vm_area_struct *vma,
 509                                   unsigned long reqprot, unsigned long prot)
 510 {
 511         return common_mmap(OP_FMPROT, vma->vm_file, prot,
 512                            !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
 513 }
 514
 515 static int apparmor_getprocattr(struct task_struct *task, char *name,
 516                                 char **value)
 517 {
 518         int error = -ENOENT;
 519         struct aa_profile *profile;
 520         /* released below */
 521         const struct cred *cred = get_task_cred(task);
 522         struct aa_task_cxt *cxt = cred->security;
 523         profile = aa_cred_profile(cred);
 524
 525         if (strcmp(name, "current") == 0)
 526                 error = aa_getprocattr(aa_newest_version(cxt->profile),
 527                                        value);
 528         else if (strcmp(name, "prev") == 0  && cxt->previous)
 529                 error = aa_getprocattr(aa_newest_version(cxt->previous),
 530                                        value);
 531         else if (strcmp(name, "exec") == 0 && cxt->onexec)
 532                 error = aa_getprocattr(aa_newest_version(cxt->onexec),
 533                                        value);
 534         else
 535                 error = -EINVAL;
 536
 537         put_cred(cred);
 538
 539         return error;
 540 }
 541
 542 static int apparmor_setprocattr(struct task_struct *task, char *name,
 543                                 void *value, size_t size)
 544 {
 545         char *command, *args = value;
 546         size_t arg_size;
 547         int error;
 548
 549         if (size == 0)
 550                 return -EINVAL;
 551         /* args points to a PAGE_SIZE buffer, AppArmor requires that
 552          * the buffer must be null terminated or have size <= PAGE_SIZE -1
 553          * so that AppArmor can null terminate them
 554          */
 555         if (args[size - 1] != '\0') {
 556                 if (size == PAGE_SIZE)
 557                         return -EINVAL;
 558                 args[size] = '\0';
 559         }
 560
 561         /* task can only write its own attributes */
 562         if (current != task)
 563                 return -EACCES;
 564
 565         args = value;
 566         args = strim(args);
 567         command = strsep(&args, " ");
 568         if (!args)
 569                 return -EINVAL;
 570         args = skip_spaces(args);
 571         if (!*args)
 572                 return -EINVAL;
 573
 574         arg_size = size - (args - (char *) value);
 575         if (strcmp(name, "current") == 0) {
 576                 if (strcmp(command, "changehat") == 0) {
 577                         error = aa_setprocattr_changehat(args, arg_size,
 578                                                          !AA_DO_TEST);
 579                 } else if (strcmp(command, "permhat") == 0) {
 580                         error = aa_setprocattr_changehat(args, arg_size,
 581                                                          AA_DO_TEST);
 582                 } else if (strcmp(command, "changeprofile") == 0) {
 583                         error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
 584                                                              !AA_DO_TEST);
 585                 } else if (strcmp(command, "permprofile") == 0) {
 586                         error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
 587                                                              AA_DO_TEST);
 588                 } else if (strcmp(command, "permipc") == 0) {
 589                         error = aa_setprocattr_permipc(args);
 590                 } else {
 591                         struct common_audit_data sa;
 592                         COMMON_AUDIT_DATA_INIT(&sa, NONE);
 593                         sa.aad.op = OP_SETPROCATTR;
 594                         sa.aad.info = name;
 595                         sa.aad.error = -EINVAL;
 596                         return aa_audit(AUDIT_APPARMOR_DENIED, NULL, GFP_KERNEL,
 597                                         &sa, NULL);
 598                 }
 599         } else if (strcmp(name, "exec") == 0) {
 600                 error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
 601                                                      !AA_DO_TEST);
 602         } else {
 603                 /* only support the "current" and "exec" process attributes */
 604                 return -EINVAL;
 605         }
 606         if (!error)
 607                 error = size;
 608         return error;
 609 }
 610
 611 static int apparmor_task_setrlimit(struct task_struct *task,
 612                 unsigned int resource, struct rlimit *new_rlim)
 613 {
 614         struct aa_profile *profile = aa_current_profile();
 615         int error = 0;
 616
 617         if (!unconfined(profile))
 618                 error = aa_task_setrlimit(profile, task, resource, new_rlim);
 619
 620         return error;
 621 }
 622
 623 static struct security_operations apparmor_ops = {
 624         .name =                         "apparmor",
 625
 626         .ptrace_access_check =          apparmor_ptrace_access_check,
 627         .ptrace_traceme =               apparmor_ptrace_traceme,
 628         .capget =                       apparmor_capget,
 629         .capable =                      apparmor_capable,
 630
 631         .path_link =                    apparmor_path_link,
 632         .path_unlink =                  apparmor_path_unlink,
 633         .path_symlink =                 apparmor_path_symlink,
 634         .path_mkdir =                   apparmor_path_mkdir,
 635         .path_rmdir =                   apparmor_path_rmdir,
 636         .path_mknod =                   apparmor_path_mknod,
 637         .path_rename =                  apparmor_path_rename,
 638         .path_chmod =                   apparmor_path_chmod,
 639         .path_chown =                   apparmor_path_chown,
 640         .path_truncate =                apparmor_path_truncate,
 641         .dentry_open =                  apparmor_dentry_open,
 642         .inode_getattr =                apparmor_inode_getattr,
 643
 644         .file_permission =              apparmor_file_permission,
 645         .file_alloc_security =          apparmor_file_alloc_security,
 646         .file_free_security =           apparmor_file_free_security,
 647         .file_mmap =                    apparmor_file_mmap,
 648         .file_mprotect =                apparmor_file_mprotect,
 649         .file_lock =                    apparmor_file_lock,
 650
 651         .getprocattr =                  apparmor_getprocattr,
 652         .setprocattr =                  apparmor_setprocattr,
 653
 654         .cred_alloc_blank =             apparmor_cred_alloc_blank,
 655         .cred_free =                    apparmor_cred_free,
 656         .cred_prepare =                 apparmor_cred_prepare,
 657         .cred_transfer =                apparmor_cred_transfer,
 658
 659         .bprm_set_creds =               apparmor_bprm_set_creds,
 660         .bprm_committing_creds =        apparmor_bprm_committing_creds,
 661         .bprm_committed_creds =         apparmor_bprm_committed_creds,
 662         .bprm_secureexec =              apparmor_bprm_secureexec,
 663
 664         .task_setrlimit =               apparmor_task_setrlimit,
 665 };
 666
 667 /*
 668  * AppArmor sysfs module parameters
 669  */
 670
 671 static int param_set_aabool(const char *val, const struct kernel_param *kp);
 672 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
 673 #define param_check_aabool(name, p) __param_check(name, p, int)
 674 static struct kernel_param_ops param_ops_aabool = {
 675         .set = param_set_aabool,
 676         .get = param_get_aabool
 677 };
 678
 679 static int param_set_aauint(const char *val, const struct kernel_param *kp);
 680 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
 681 #define param_check_aauint(name, p) __param_check(name, p, int)
 682 static struct kernel_param_ops param_ops_aauint = {
 683         .set = param_set_aauint,
 684         .get = param_get_aauint
 685 };
 686
 687 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
 688 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
 689 #define param_check_aalockpolicy(name, p) __param_check(name, p, int)
 690 static struct kernel_param_ops param_ops_aalockpolicy = {
 691         .set = param_set_aalockpolicy,
 692         .get = param_get_aalockpolicy
 693 };
 694
 695 static int param_set_audit(const char *val, struct kernel_param *kp);
 696 static int param_get_audit(char *buffer, struct kernel_param *kp);
 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
 701 /* Flag values, also controllable via /sys/module/apparmor/parameters
 702  * We define special types as we want to do additional mediation.
 703  */
 704
 705 /* AppArmor global enforcement switch - complain, enforce, kill */
 706 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
 707 module_param_call(mode, param_set_mode, param_get_mode,
 708                   &aa_g_profile_mode, S_IRUSR | S_IWUSR);
 709
 710 /* Debug mode */
 711 int aa_g_debug;
 712 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
 713
 714 /* Audit mode */
 715 enum audit_mode aa_g_audit;
 716 module_param_call(audit, param_set_audit, param_get_audit,
 717                   &aa_g_audit, S_IRUSR | S_IWUSR);
 718
 719 /* Determines if audit header is included in audited messages.  This
 720  * provides more context if the audit daemon is not running
 721  */
 722 int aa_g_audit_header = 1;
 723 module_param_named(audit_header, aa_g_audit_header, aabool,
 724                    S_IRUSR | S_IWUSR);
 725
 726 /* lock out loading/removal of policy
 727  * TODO: add in at boot loading of policy, which is the only way to
 728  *       load policy, if lock_policy is set
 729  */
 730 int aa_g_lock_policy;
 731 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
 732                    S_IRUSR | S_IWUSR);
 733
 734 /* Syscall logging mode */
 735 int aa_g_logsyscall;
 736 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
 737
 738 /* Maximum pathname length before accesses will start getting rejected */
 739 unsigned int aa_g_path_max = 2 * PATH_MAX;
 740 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
 741
 742 /* Determines how paranoid loading of policy is and how much verification
 743  * on the loaded policy is done.
 744  */
 745 int aa_g_paranoid_load = 1;
 746 module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
 747                    S_IRUSR | S_IWUSR);
 748
 749 /* Boot time disable flag */
 750 static unsigned int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
 751 module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);
 752
 753 static int __init apparmor_enabled_setup(char *str)
 754 {
 755         unsigned long enabled;
 756         int error = strict_strtoul(str, 0, &enabled);
 757         if (!error)
 758                 apparmor_enabled = enabled ? 1 : 0;
 759         return 1;
 760 }
 761
 762 __setup("apparmor=", apparmor_enabled_setup);
 763
 764 /* set global flag turning off the ability to load policy */
 765 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
 766 {
 767         if (!capable(CAP_MAC_ADMIN))
 768                 return -EPERM;
 769         if (aa_g_lock_policy)
 770                 return -EACCES;
 771         return param_set_bool(val, kp);
 772 }
 773
 774 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
 775 {
 776         if (!capable(CAP_MAC_ADMIN))
 777                 return -EPERM;
 778         return param_get_bool(buffer, kp);
 779 }
 780
 781 static int param_set_aabool(const char *val, const struct kernel_param *kp)
 782 {
 783         if (!capable(CAP_MAC_ADMIN))
 784                 return -EPERM;
 785         return param_set_bool(val, kp);
 786 }
 787
 788 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
 789 {
 790         if (!capable(CAP_MAC_ADMIN))
 791                 return -EPERM;
 792         return param_get_bool(buffer, kp);
 793 }
 794
 795 static int param_set_aauint(const char *val, const struct kernel_param *kp)
 796 {
 797         if (!capable(CAP_MAC_ADMIN))
 798                 return -EPERM;
 799         return param_set_uint(val, kp);
 800 }
 801
 802 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
 803 {
 804         if (!capable(CAP_MAC_ADMIN))
 805                 return -EPERM;
 806         return param_get_uint(buffer, kp);
 807 }
 808
 809 static int param_get_audit(char *buffer, struct kernel_param *kp)
 810 {
 811         if (!capable(CAP_MAC_ADMIN))
 812                 return -EPERM;
 813
 814         if (!apparmor_enabled)
 815                 return -EINVAL;
 816
 817         return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
 818 }
 819
 820 static int param_set_audit(const char *val, struct kernel_param *kp)
 821 {
 822         int i;
 823         if (!capable(CAP_MAC_ADMIN))
 824                 return -EPERM;
 825
 826         if (!apparmor_enabled)
 827                 return -EINVAL;
 828
 829         if (!val)
 830                 return -EINVAL;
 831
 832         for (i = 0; i < AUDIT_MAX_INDEX; i++) {
 833                 if (strcmp(val, audit_mode_names[i]) == 0) {
 834                         aa_g_audit = i;
 835                         return 0;
 836                 }
 837         }
 838
 839         return -EINVAL;
 840 }
 841
 842 static int param_get_mode(char *buffer, struct kernel_param *kp)
 843 {
 844         if (!capable(CAP_MAC_ADMIN))
 845                 return -EPERM;
 846
 847         if (!apparmor_enabled)
 848                 return -EINVAL;
 849
 850         return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
 851 }
 852
 853 static int param_set_mode(const char *val, struct kernel_param *kp)
 854 {
 855         int i;
 856         if (!capable(CAP_MAC_ADMIN))
 857                 return -EPERM;
 858
 859         if (!apparmor_enabled)
 860                 return -EINVAL;
 861
 862         if (!val)
 863                 return -EINVAL;
 864
 865         for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
 866                 if (strcmp(val, profile_mode_names[i]) == 0) {
 867                         aa_g_profile_mode = i;
 868                         return 0;
 869                 }
 870         }
 871
 872         return -EINVAL;
 873 }
 874
 875 /*
 876  * AppArmor init functions
 877  */
 878
 879 /**
 880  * set_init_cxt - set a task context and profile on the first task.
 881  *
 882  * TODO: allow setting an alternate profile than unconfined
 883  */
 884 static int __init set_init_cxt(void)
 885 {
 886         struct cred *cred = (struct cred *)current->real_cred;
 887         struct aa_task_cxt *cxt;
 888
 889         cxt = aa_alloc_task_context(GFP_KERNEL);
 890         if (!cxt)
 891                 return -ENOMEM;
 892
 893         cxt->profile = aa_get_profile(root_ns->unconfined);
 894         cred->security = cxt;
 895
 896         return 0;
 897 }
 898
 899 static int __init apparmor_init(void)
 900 {
 901         int error;
 902
 903         if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
 904                 aa_info_message("AppArmor disabled by boot time parameter");
 905                 apparmor_enabled = 0;
 906                 return 0;
 907         }
 908
 909         error = aa_alloc_root_ns();
 910         if (error) {
 911                 AA_ERROR("Unable to allocate default profile namespace\n");
 912                 goto alloc_out;
 913         }
 914
 915         error = set_init_cxt();
 916         if (error) {
 917                 AA_ERROR("Failed to set context on init task\n");
 918                 goto register_security_out;
 919         }
 920
 921         error = register_security(&apparmor_ops);
 922         if (error) {
 923                 AA_ERROR("Unable to register AppArmor\n");
 924                 goto set_init_cxt_out;
 925         }
 926
 927         /* Report that AppArmor successfully initialized */
 928         apparmor_initialized = 1;
 929         if (aa_g_profile_mode == APPARMOR_COMPLAIN)
 930                 aa_info_message("AppArmor initialized: complain mode enabled");
 931         else if (aa_g_profile_mode == APPARMOR_KILL)
 932                 aa_info_message("AppArmor initialized: kill mode enabled");
 933         else
 934                 aa_info_message("AppArmor initialized");
 935
 936         return error;
 937
 938 set_init_cxt_out:
 939         aa_free_task_context(current->real_cred->security);
 940
 941 register_security_out:
 942         aa_free_root_ns();
 943
 944 alloc_out:
 945         aa_destroy_aafs();
 946
 947         apparmor_enabled = 0;
 948         return error;
 949 }
 950
 951 security_initcall(apparmor_init);