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, loff_t length,
 282                                   unsigned int time_attrs)
 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(unsigned int resource,
 612                                    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, 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, struct kernel_param *kp);
 672 static int param_get_aabool(char *buffer, struct kernel_param *kp);
 673 #define param_check_aabool(name, p) __param_check(name, p, int)
 674
 675 static int param_set_aauint(const char *val, struct kernel_param *kp);
 676 static int param_get_aauint(char *buffer, struct kernel_param *kp);
 677 #define param_check_aauint(name, p) __param_check(name, p, int)
 678
 679 static int param_set_aalockpolicy(const char *val, struct kernel_param *kp);
 680 static int param_get_aalockpolicy(char *buffer, struct kernel_param *kp);
 681 #define param_check_aalockpolicy(name, p) __param_check(name, p, int)
 682
 683 static int param_set_audit(const char *val, struct kernel_param *kp);
 684 static int param_get_audit(char *buffer, struct kernel_param *kp);
 685 #define param_check_audit(name, p) __param_check(name, p, int)
 686
 687 static int param_set_mode(const char *val, struct kernel_param *kp);
 688 static int param_get_mode(char *buffer, struct kernel_param *kp);
 689 #define param_check_mode(name, p) __param_check(name, p, int)
 690
 691 /* Flag values, also controllable via /sys/module/apparmor/parameters
 692  * We define special types as we want to do additional mediation.
 693  */
 694
 695 /* AppArmor global enforcement switch - complain, enforce, kill */
 696 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
 697 module_param_call(mode, param_set_mode, param_get_mode,
 698                   &aa_g_profile_mode, S_IRUSR | S_IWUSR);
 699
 700 /* Debug mode */
 701 int aa_g_debug;
 702 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
 703
 704 /* Audit mode */
 705 enum audit_mode aa_g_audit;
 706 module_param_call(audit, param_set_audit, param_get_audit,
 707                   &aa_g_audit, S_IRUSR | S_IWUSR);
 708
 709 /* Determines if audit header is included in audited messages.  This
 710  * provides more context if the audit daemon is not running
 711  */
 712 int aa_g_audit_header = 1;
 713 module_param_named(audit_header, aa_g_audit_header, aabool,
 714                    S_IRUSR | S_IWUSR);
 715
 716 /* lock out loading/removal of policy
 717  * TODO: add in at boot loading of policy, which is the only way to
 718  *       load policy, if lock_policy is set
 719  */
 720 int aa_g_lock_policy;
 721 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
 722                    S_IRUSR | S_IWUSR);
 723
 724 /* Syscall logging mode */
 725 int aa_g_logsyscall;
 726 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
 727
 728 /* Maximum pathname length before accesses will start getting rejected */
 729 unsigned int aa_g_path_max = 2 * PATH_MAX;
 730 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
 731
 732 /* Determines how paranoid loading of policy is and how much verification
 733  * on the loaded policy is done.
 734  */
 735 int aa_g_paranoid_load = 1;
 736 module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
 737                    S_IRUSR | S_IWUSR);
 738
 739 /* Boot time disable flag */
 740 static unsigned int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
 741 module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);
 742
 743 static int __init apparmor_enabled_setup(char *str)
 744 {
 745         unsigned long enabled;
 746         int error = strict_strtoul(str, 0, &enabled);
 747         if (!error)
 748                 apparmor_enabled = enabled ? 1 : 0;
 749         return 1;
 750 }
 751
 752 __setup("apparmor=", apparmor_enabled_setup);
 753
 754 /* set global flag turning off the ability to load policy */
 755 static int param_set_aalockpolicy(const char *val, struct kernel_param *kp)
 756 {
 757         if (!capable(CAP_MAC_ADMIN))
 758                 return -EPERM;
 759         if (aa_g_lock_policy)
 760                 return -EACCES;
 761         return param_set_bool(val, kp);
 762 }
 763
 764 static int param_get_aalockpolicy(char *buffer, struct kernel_param *kp)
 765 {
 766         if (!capable(CAP_MAC_ADMIN))
 767                 return -EPERM;
 768         return param_get_bool(buffer, kp);
 769 }
 770
 771 static int param_set_aabool(const char *val, struct kernel_param *kp)
 772 {
 773         if (!capable(CAP_MAC_ADMIN))
 774                 return -EPERM;
 775         return param_set_bool(val, kp);
 776 }
 777
 778 static int param_get_aabool(char *buffer, struct kernel_param *kp)
 779 {
 780         if (!capable(CAP_MAC_ADMIN))
 781                 return -EPERM;
 782         return param_get_bool(buffer, kp);
 783 }
 784
 785 static int param_set_aauint(const char *val, struct kernel_param *kp)
 786 {
 787         if (!capable(CAP_MAC_ADMIN))
 788                 return -EPERM;
 789         return param_set_uint(val, kp);
 790 }
 791
 792 static int param_get_aauint(char *buffer, struct kernel_param *kp)
 793 {
 794         if (!capable(CAP_MAC_ADMIN))
 795                 return -EPERM;
 796         return param_get_uint(buffer, kp);
 797 }
 798
 799 static int param_get_audit(char *buffer, struct kernel_param *kp)
 800 {
 801         if (!capable(CAP_MAC_ADMIN))
 802                 return -EPERM;
 803
 804         if (!apparmor_enabled)
 805                 return -EINVAL;
 806
 807         return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
 808 }
 809
 810 static int param_set_audit(const char *val, struct kernel_param *kp)
 811 {
 812         int i;
 813         if (!capable(CAP_MAC_ADMIN))
 814                 return -EPERM;
 815
 816         if (!apparmor_enabled)
 817                 return -EINVAL;
 818
 819         if (!val)
 820                 return -EINVAL;
 821
 822         for (i = 0; i < AUDIT_MAX_INDEX; i++) {
 823                 if (strcmp(val, audit_mode_names[i]) == 0) {
 824                         aa_g_audit = i;
 825                         return 0;
 826                 }
 827         }
 828
 829         return -EINVAL;
 830 }
 831
 832 static int param_get_mode(char *buffer, struct kernel_param *kp)
 833 {
 834         if (!capable(CAP_MAC_ADMIN))
 835                 return -EPERM;
 836
 837         if (!apparmor_enabled)
 838                 return -EINVAL;
 839
 840         return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
 841 }
 842
 843 static int param_set_mode(const char *val, struct kernel_param *kp)
 844 {
 845         int i;
 846         if (!capable(CAP_MAC_ADMIN))
 847                 return -EPERM;
 848
 849         if (!apparmor_enabled)
 850                 return -EINVAL;
 851
 852         if (!val)
 853                 return -EINVAL;
 854
 855         for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
 856                 if (strcmp(val, profile_mode_names[i]) == 0) {
 857                         aa_g_profile_mode = i;
 858                         return 0;
 859                 }
 860         }
 861
 862         return -EINVAL;
 863 }
 864
 865 /*
 866  * AppArmor init functions
 867  */
 868
 869 /**
 870  * set_init_cxt - set a task context and profile on the first task.
 871  *
 872  * TODO: allow setting an alternate profile than unconfined
 873  */
 874 static int __init set_init_cxt(void)
 875 {
 876         struct cred *cred = (struct cred *)current->real_cred;
 877         struct aa_task_cxt *cxt;
 878
 879         cxt = aa_alloc_task_context(GFP_KERNEL);
 880         if (!cxt)
 881                 return -ENOMEM;
 882
 883         cxt->profile = aa_get_profile(root_ns->unconfined);
 884         cred->security = cxt;
 885
 886         return 0;
 887 }
 888
 889 static int __init apparmor_init(void)
 890 {
 891         int error;
 892
 893         if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
 894                 aa_info_message("AppArmor disabled by boot time parameter");
 895                 apparmor_enabled = 0;
 896                 return 0;
 897         }
 898
 899         error = aa_alloc_root_ns();
 900         if (error) {
 901                 AA_ERROR("Unable to allocate default profile namespace\n");
 902                 goto alloc_out;
 903         }
 904
 905         error = set_init_cxt();
 906         if (error) {
 907                 AA_ERROR("Failed to set context on init task\n");
 908                 goto register_security_out;
 909         }
 910
 911         error = register_security(&apparmor_ops);
 912         if (error) {
 913                 AA_ERROR("Unable to register AppArmor\n");
 914                 goto register_security_out;
 915         }
 916
 917         /* Report that AppArmor successfully initialized */
 918         apparmor_initialized = 1;
 919         if (aa_g_profile_mode == APPARMOR_COMPLAIN)
 920                 aa_info_message("AppArmor initialized: complain mode enabled");
 921         else if (aa_g_profile_mode == APPARMOR_KILL)
 922                 aa_info_message("AppArmor initialized: kill mode enabled");
 923         else
 924                 aa_info_message("AppArmor initialized");
 925
 926         return error;
 927
 928 register_security_out:
 929         aa_free_root_ns();
 930
 931 alloc_out:
 932         aa_destroy_aafs();
 933
 934         apparmor_enabled = 0;
 935         return error;
 936
 937 }
 938
 939 security_initcall(apparmor_init);