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Linux/security/apparmor/lsm.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * AppArmor security module
  4  *
  5  * This file contains AppArmor LSM hooks.
  6  *
  7  * Copyright (C) 1998-2008 Novell/SUSE
  8  * Copyright 2009-2010 Canonical Ltd.
  9  */
 10 
 11 #include <linux/lsm_hooks.h>
 12 #include <linux/moduleparam.h>
 13 #include <linux/mm.h>
 14 #include <linux/mman.h>
 15 #include <linux/mount.h>
 16 #include <linux/namei.h>
 17 #include <linux/ptrace.h>
 18 #include <linux/ctype.h>
 19 #include <linux/sysctl.h>
 20 #include <linux/audit.h>
 21 #include <linux/user_namespace.h>
 22 #include <linux/netfilter_ipv4.h>
 23 #include <linux/netfilter_ipv6.h>
 24 #include <linux/zlib.h>
 25 #include <net/sock.h>
 26 #include <uapi/linux/mount.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/cred.h"
 33 #include "include/file.h"
 34 #include "include/ipc.h"
 35 #include "include/net.h"
 36 #include "include/path.h"
 37 #include "include/label.h"
 38 #include "include/policy.h"
 39 #include "include/policy_ns.h"
 40 #include "include/procattr.h"
 41 #include "include/mount.h"
 42 #include "include/secid.h"
 43 
 44 /* Flag indicating whether initialization completed */
 45 int apparmor_initialized;
 46 
 47 union aa_buffer {
 48         struct list_head list;
 49         char buffer[1];
 50 };
 51 
 52 #define RESERVE_COUNT 2
 53 static int reserve_count = RESERVE_COUNT;
 54 static int buffer_count;
 55 
 56 static LIST_HEAD(aa_global_buffers);
 57 static DEFINE_SPINLOCK(aa_buffers_lock);
 58 
 59 /*
 60  * LSM hook functions
 61  */
 62 
 63 /*
 64  * put the associated labels
 65  */
 66 static void apparmor_cred_free(struct cred *cred)
 67 {
 68         aa_put_label(cred_label(cred));
 69         set_cred_label(cred, NULL);
 70 }
 71 
 72 /*
 73  * allocate the apparmor part of blank credentials
 74  */
 75 static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
 76 {
 77         set_cred_label(cred, NULL);
 78         return 0;
 79 }
 80 
 81 /*
 82  * prepare new cred label for modification by prepare_cred block
 83  */
 84 static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
 85                                  gfp_t gfp)
 86 {
 87         set_cred_label(new, aa_get_newest_label(cred_label(old)));
 88         return 0;
 89 }
 90 
 91 /*
 92  * transfer the apparmor data to a blank set of creds
 93  */
 94 static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
 95 {
 96         set_cred_label(new, aa_get_newest_label(cred_label(old)));
 97 }
 98 
 99 static void apparmor_task_free(struct task_struct *task)
100 {
101 
102         aa_free_task_ctx(task_ctx(task));
103 }
104 
105 static int apparmor_task_alloc(struct task_struct *task,
106                                unsigned long clone_flags)
107 {
108         struct aa_task_ctx *new = task_ctx(task);
109 
110         aa_dup_task_ctx(new, task_ctx(current));
111 
112         return 0;
113 }
114 
115 static int apparmor_ptrace_access_check(struct task_struct *child,
116                                         unsigned int mode)
117 {
118         struct aa_label *tracer, *tracee;
119         int error;
120 
121         tracer = __begin_current_label_crit_section();
122         tracee = aa_get_task_label(child);
123         error = aa_may_ptrace(tracer, tracee,
124                         (mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
125                                                   : AA_PTRACE_TRACE);
126         aa_put_label(tracee);
127         __end_current_label_crit_section(tracer);
128 
129         return error;
130 }
131 
132 static int apparmor_ptrace_traceme(struct task_struct *parent)
133 {
134         struct aa_label *tracer, *tracee;
135         int error;
136 
137         tracee = __begin_current_label_crit_section();
138         tracer = aa_get_task_label(parent);
139         error = aa_may_ptrace(tracer, tracee, AA_PTRACE_TRACE);
140         aa_put_label(tracer);
141         __end_current_label_crit_section(tracee);
142 
143         return error;
144 }
145 
146 /* Derived from security/commoncap.c:cap_capget */
147 static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
148                            kernel_cap_t *inheritable, kernel_cap_t *permitted)
149 {
150         struct aa_label *label;
151         const struct cred *cred;
152 
153         rcu_read_lock();
154         cred = __task_cred(target);
155         label = aa_get_newest_cred_label(cred);
156 
157         /*
158          * cap_capget is stacked ahead of this and will
159          * initialize effective and permitted.
160          */
161         if (!unconfined(label)) {
162                 struct aa_profile *profile;
163                 struct label_it i;
164 
165                 label_for_each_confined(i, label, profile) {
166                         if (COMPLAIN_MODE(profile))
167                                 continue;
168                         *effective = cap_intersect(*effective,
169                                                    profile->caps.allow);
170                         *permitted = cap_intersect(*permitted,
171                                                    profile->caps.allow);
172                 }
173         }
174         rcu_read_unlock();
175         aa_put_label(label);
176 
177         return 0;
178 }
179 
180 static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
181                             int cap, unsigned int opts)
182 {
183         struct aa_label *label;
184         int error = 0;
185 
186         label = aa_get_newest_cred_label(cred);
187         if (!unconfined(label))
188                 error = aa_capable(label, cap, opts);
189         aa_put_label(label);
190 
191         return error;
192 }
193 
194 /**
195  * common_perm - basic common permission check wrapper fn for paths
196  * @op: operation being checked
197  * @path: path to check permission of  (NOT NULL)
198  * @mask: requested permissions mask
199  * @cond: conditional info for the permission request  (NOT NULL)
200  *
201  * Returns: %0 else error code if error or permission denied
202  */
203 static int common_perm(const char *op, const struct path *path, u32 mask,
204                        struct path_cond *cond)
205 {
206         struct aa_label *label;
207         int error = 0;
208 
209         label = __begin_current_label_crit_section();
210         if (!unconfined(label))
211                 error = aa_path_perm(op, label, path, 0, mask, cond);
212         __end_current_label_crit_section(label);
213 
214         return error;
215 }
216 
217 /**
218  * common_perm_cond - common permission wrapper around inode cond
219  * @op: operation being checked
220  * @path: location to check (NOT NULL)
221  * @mask: requested permissions mask
222  *
223  * Returns: %0 else error code if error or permission denied
224  */
225 static int common_perm_cond(const char *op, const struct path *path, u32 mask)
226 {
227         struct path_cond cond = { d_backing_inode(path->dentry)->i_uid,
228                                   d_backing_inode(path->dentry)->i_mode
229         };
230 
231         if (!path_mediated_fs(path->dentry))
232                 return 0;
233 
234         return common_perm(op, path, mask, &cond);
235 }
236 
237 /**
238  * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
239  * @op: operation being checked
240  * @dir: directory of the dentry  (NOT NULL)
241  * @dentry: dentry to check  (NOT NULL)
242  * @mask: requested permissions mask
243  * @cond: conditional info for the permission request  (NOT NULL)
244  *
245  * Returns: %0 else error code if error or permission denied
246  */
247 static int common_perm_dir_dentry(const char *op, const struct path *dir,
248                                   struct dentry *dentry, u32 mask,
249                                   struct path_cond *cond)
250 {
251         struct path path = { .mnt = dir->mnt, .dentry = dentry };
252 
253         return common_perm(op, &path, mask, cond);
254 }
255 
256 /**
257  * common_perm_rm - common permission wrapper for operations doing rm
258  * @op: operation being checked
259  * @dir: directory that the dentry is in  (NOT NULL)
260  * @dentry: dentry being rm'd  (NOT NULL)
261  * @mask: requested permission mask
262  *
263  * Returns: %0 else error code if error or permission denied
264  */
265 static int common_perm_rm(const char *op, const struct path *dir,
266                           struct dentry *dentry, u32 mask)
267 {
268         struct inode *inode = d_backing_inode(dentry);
269         struct path_cond cond = { };
270 
271         if (!inode || !path_mediated_fs(dentry))
272                 return 0;
273 
274         cond.uid = inode->i_uid;
275         cond.mode = inode->i_mode;
276 
277         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
278 }
279 
280 /**
281  * common_perm_create - common permission wrapper for operations doing create
282  * @op: operation being checked
283  * @dir: directory that dentry will be created in  (NOT NULL)
284  * @dentry: dentry to create   (NOT NULL)
285  * @mask: request permission mask
286  * @mode: created file mode
287  *
288  * Returns: %0 else error code if error or permission denied
289  */
290 static int common_perm_create(const char *op, const struct path *dir,
291                               struct dentry *dentry, u32 mask, umode_t mode)
292 {
293         struct path_cond cond = { current_fsuid(), mode };
294 
295         if (!path_mediated_fs(dir->dentry))
296                 return 0;
297 
298         return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
299 }
300 
301 static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
302 {
303         return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
304 }
305 
306 static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
307                                umode_t mode)
308 {
309         return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
310                                   S_IFDIR);
311 }
312 
313 static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
314 {
315         return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
316 }
317 
318 static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
319                                umode_t mode, unsigned int dev)
320 {
321         return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
322 }
323 
324 static int apparmor_path_truncate(const struct path *path)
325 {
326         return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
327 }
328 
329 static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
330                                  const char *old_name)
331 {
332         return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
333                                   S_IFLNK);
334 }
335 
336 static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
337                               struct dentry *new_dentry)
338 {
339         struct aa_label *label;
340         int error = 0;
341 
342         if (!path_mediated_fs(old_dentry))
343                 return 0;
344 
345         label = begin_current_label_crit_section();
346         if (!unconfined(label))
347                 error = aa_path_link(label, old_dentry, new_dir, new_dentry);
348         end_current_label_crit_section(label);
349 
350         return error;
351 }
352 
353 static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
354                                 const struct path *new_dir, struct dentry *new_dentry)
355 {
356         struct aa_label *label;
357         int error = 0;
358 
359         if (!path_mediated_fs(old_dentry))
360                 return 0;
361 
362         label = begin_current_label_crit_section();
363         if (!unconfined(label)) {
364                 struct path old_path = { .mnt = old_dir->mnt,
365                                          .dentry = old_dentry };
366                 struct path new_path = { .mnt = new_dir->mnt,
367                                          .dentry = new_dentry };
368                 struct path_cond cond = { d_backing_inode(old_dentry)->i_uid,
369                                           d_backing_inode(old_dentry)->i_mode
370                 };
371 
372                 error = aa_path_perm(OP_RENAME_SRC, label, &old_path, 0,
373                                      MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
374                                      AA_MAY_SETATTR | AA_MAY_DELETE,
375                                      &cond);
376                 if (!error)
377                         error = aa_path_perm(OP_RENAME_DEST, label, &new_path,
378                                              0, MAY_WRITE | AA_MAY_SETATTR |
379                                              AA_MAY_CREATE, &cond);
380 
381         }
382         end_current_label_crit_section(label);
383 
384         return error;
385 }
386 
387 static int apparmor_path_chmod(const struct path *path, umode_t mode)
388 {
389         return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
390 }
391 
392 static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
393 {
394         return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
395 }
396 
397 static int apparmor_inode_getattr(const struct path *path)
398 {
399         return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
400 }
401 
402 static int apparmor_file_open(struct file *file)
403 {
404         struct aa_file_ctx *fctx = file_ctx(file);
405         struct aa_label *label;
406         int error = 0;
407 
408         if (!path_mediated_fs(file->f_path.dentry))
409                 return 0;
410 
411         /* If in exec, permission is handled by bprm hooks.
412          * Cache permissions granted by the previous exec check, with
413          * implicit read and executable mmap which are required to
414          * actually execute the image.
415          */
416         if (current->in_execve) {
417                 fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
418                 return 0;
419         }
420 
421         label = aa_get_newest_cred_label(file->f_cred);
422         if (!unconfined(label)) {
423                 struct inode *inode = file_inode(file);
424                 struct path_cond cond = { inode->i_uid, inode->i_mode };
425 
426                 error = aa_path_perm(OP_OPEN, label, &file->f_path, 0,
427                                      aa_map_file_to_perms(file), &cond);
428                 /* todo cache full allowed permissions set and state */
429                 fctx->allow = aa_map_file_to_perms(file);
430         }
431         aa_put_label(label);
432 
433         return error;
434 }
435 
436 static int apparmor_file_alloc_security(struct file *file)
437 {
438         struct aa_file_ctx *ctx = file_ctx(file);
439         struct aa_label *label = begin_current_label_crit_section();
440 
441         spin_lock_init(&ctx->lock);
442         rcu_assign_pointer(ctx->label, aa_get_label(label));
443         end_current_label_crit_section(label);
444         return 0;
445 }
446 
447 static void apparmor_file_free_security(struct file *file)
448 {
449         struct aa_file_ctx *ctx = file_ctx(file);
450 
451         if (ctx)
452                 aa_put_label(rcu_access_pointer(ctx->label));
453 }
454 
455 static int common_file_perm(const char *op, struct file *file, u32 mask,
456                             bool in_atomic)
457 {
458         struct aa_label *label;
459         int error = 0;
460 
461         /* don't reaudit files closed during inheritance */
462         if (file->f_path.dentry == aa_null.dentry)
463                 return -EACCES;
464 
465         label = __begin_current_label_crit_section();
466         error = aa_file_perm(op, label, file, mask, in_atomic);
467         __end_current_label_crit_section(label);
468 
469         return error;
470 }
471 
472 static int apparmor_file_receive(struct file *file)
473 {
474         return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file),
475                                 false);
476 }
477 
478 static int apparmor_file_permission(struct file *file, int mask)
479 {
480         return common_file_perm(OP_FPERM, file, mask, false);
481 }
482 
483 static int apparmor_file_lock(struct file *file, unsigned int cmd)
484 {
485         u32 mask = AA_MAY_LOCK;
486 
487         if (cmd == F_WRLCK)
488                 mask |= MAY_WRITE;
489 
490         return common_file_perm(OP_FLOCK, file, mask, false);
491 }
492 
493 static int common_mmap(const char *op, struct file *file, unsigned long prot,
494                        unsigned long flags, bool in_atomic)
495 {
496         int mask = 0;
497 
498         if (!file || !file_ctx(file))
499                 return 0;
500 
501         if (prot & PROT_READ)
502                 mask |= MAY_READ;
503         /*
504          * Private mappings don't require write perms since they don't
505          * write back to the files
506          */
507         if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
508                 mask |= MAY_WRITE;
509         if (prot & PROT_EXEC)
510                 mask |= AA_EXEC_MMAP;
511 
512         return common_file_perm(op, file, mask, in_atomic);
513 }
514 
515 static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
516                               unsigned long prot, unsigned long flags)
517 {
518         return common_mmap(OP_FMMAP, file, prot, flags, GFP_ATOMIC);
519 }
520 
521 static int apparmor_file_mprotect(struct vm_area_struct *vma,
522                                   unsigned long reqprot, unsigned long prot)
523 {
524         return common_mmap(OP_FMPROT, vma->vm_file, prot,
525                            !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0,
526                            false);
527 }
528 
529 static int apparmor_sb_mount(const char *dev_name, const struct path *path,
530                              const char *type, unsigned long flags, void *data)
531 {
532         struct aa_label *label;
533         int error = 0;
534 
535         /* Discard magic */
536         if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
537                 flags &= ~MS_MGC_MSK;
538 
539         flags &= ~AA_MS_IGNORE_MASK;
540 
541         label = __begin_current_label_crit_section();
542         if (!unconfined(label)) {
543                 if (flags & MS_REMOUNT)
544                         error = aa_remount(label, path, flags, data);
545                 else if (flags & MS_BIND)
546                         error = aa_bind_mount(label, path, dev_name, flags);
547                 else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
548                                   MS_UNBINDABLE))
549                         error = aa_mount_change_type(label, path, flags);
550                 else if (flags & MS_MOVE)
551                         error = aa_move_mount(label, path, dev_name);
552                 else
553                         error = aa_new_mount(label, dev_name, path, type,
554                                              flags, data);
555         }
556         __end_current_label_crit_section(label);
557 
558         return error;
559 }
560 
561 static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
562 {
563         struct aa_label *label;
564         int error = 0;
565 
566         label = __begin_current_label_crit_section();
567         if (!unconfined(label))
568                 error = aa_umount(label, mnt, flags);
569         __end_current_label_crit_section(label);
570 
571         return error;
572 }
573 
574 static int apparmor_sb_pivotroot(const struct path *old_path,
575                                  const struct path *new_path)
576 {
577         struct aa_label *label;
578         int error = 0;
579 
580         label = aa_get_current_label();
581         if (!unconfined(label))
582                 error = aa_pivotroot(label, old_path, new_path);
583         aa_put_label(label);
584 
585         return error;
586 }
587 
588 static int apparmor_getprocattr(struct task_struct *task, char *name,
589                                 char **value)
590 {
591         int error = -ENOENT;
592         /* released below */
593         const struct cred *cred = get_task_cred(task);
594         struct aa_task_ctx *ctx = task_ctx(current);
595         struct aa_label *label = NULL;
596 
597         if (strcmp(name, "current") == 0)
598                 label = aa_get_newest_label(cred_label(cred));
599         else if (strcmp(name, "prev") == 0  && ctx->previous)
600                 label = aa_get_newest_label(ctx->previous);
601         else if (strcmp(name, "exec") == 0 && ctx->onexec)
602                 label = aa_get_newest_label(ctx->onexec);
603         else
604                 error = -EINVAL;
605 
606         if (label)
607                 error = aa_getprocattr(label, value);
608 
609         aa_put_label(label);
610         put_cred(cred);
611 
612         return error;
613 }
614 
615 static int apparmor_setprocattr(const char *name, void *value,
616                                 size_t size)
617 {
618         char *command, *largs = NULL, *args = value;
619         size_t arg_size;
620         int error;
621         DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETPROCATTR);
622 
623         if (size == 0)
624                 return -EINVAL;
625 
626         /* AppArmor requires that the buffer must be null terminated atm */
627         if (args[size - 1] != '\0') {
628                 /* null terminate */
629                 largs = args = kmalloc(size + 1, GFP_KERNEL);
630                 if (!args)
631                         return -ENOMEM;
632                 memcpy(args, value, size);
633                 args[size] = '\0';
634         }
635 
636         error = -EINVAL;
637         args = strim(args);
638         command = strsep(&args, " ");
639         if (!args)
640                 goto out;
641         args = skip_spaces(args);
642         if (!*args)
643                 goto out;
644 
645         arg_size = size - (args - (largs ? largs : (char *) value));
646         if (strcmp(name, "current") == 0) {
647                 if (strcmp(command, "changehat") == 0) {
648                         error = aa_setprocattr_changehat(args, arg_size,
649                                                          AA_CHANGE_NOFLAGS);
650                 } else if (strcmp(command, "permhat") == 0) {
651                         error = aa_setprocattr_changehat(args, arg_size,
652                                                          AA_CHANGE_TEST);
653                 } else if (strcmp(command, "changeprofile") == 0) {
654                         error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
655                 } else if (strcmp(command, "permprofile") == 0) {
656                         error = aa_change_profile(args, AA_CHANGE_TEST);
657                 } else if (strcmp(command, "stack") == 0) {
658                         error = aa_change_profile(args, AA_CHANGE_STACK);
659                 } else
660                         goto fail;
661         } else if (strcmp(name, "exec") == 0) {
662                 if (strcmp(command, "exec") == 0)
663                         error = aa_change_profile(args, AA_CHANGE_ONEXEC);
664                 else if (strcmp(command, "stack") == 0)
665                         error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
666                                                          AA_CHANGE_STACK));
667                 else
668                         goto fail;
669         } else
670                 /* only support the "current" and "exec" process attributes */
671                 goto fail;
672 
673         if (!error)
674                 error = size;
675 out:
676         kfree(largs);
677         return error;
678 
679 fail:
680         aad(&sa)->label = begin_current_label_crit_section();
681         aad(&sa)->info = name;
682         aad(&sa)->error = error = -EINVAL;
683         aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
684         end_current_label_crit_section(aad(&sa)->label);
685         goto out;
686 }
687 
688 /**
689  * apparmor_bprm_committing_creds - do task cleanup on committing new creds
690  * @bprm: binprm for the exec  (NOT NULL)
691  */
692 static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
693 {
694         struct aa_label *label = aa_current_raw_label();
695         struct aa_label *new_label = cred_label(bprm->cred);
696 
697         /* bail out if unconfined or not changing profile */
698         if ((new_label->proxy == label->proxy) ||
699             (unconfined(new_label)))
700                 return;
701 
702         aa_inherit_files(bprm->cred, current->files);
703 
704         current->pdeath_signal = 0;
705 
706         /* reset soft limits and set hard limits for the new label */
707         __aa_transition_rlimits(label, new_label);
708 }
709 
710 /**
711  * apparmor_bprm_committed_cred - do cleanup after new creds committed
712  * @bprm: binprm for the exec  (NOT NULL)
713  */
714 static void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
715 {
716         /* clear out temporary/transitional state from the context */
717         aa_clear_task_ctx_trans(task_ctx(current));
718 
719         return;
720 }
721 
722 static void apparmor_task_getsecid(struct task_struct *p, u32 *secid)
723 {
724         struct aa_label *label = aa_get_task_label(p);
725         *secid = label->secid;
726         aa_put_label(label);
727 }
728 
729 static int apparmor_task_setrlimit(struct task_struct *task,
730                 unsigned int resource, struct rlimit *new_rlim)
731 {
732         struct aa_label *label = __begin_current_label_crit_section();
733         int error = 0;
734 
735         if (!unconfined(label))
736                 error = aa_task_setrlimit(label, task, resource, new_rlim);
737         __end_current_label_crit_section(label);
738 
739         return error;
740 }
741 
742 static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo *info,
743                               int sig, const struct cred *cred)
744 {
745         struct aa_label *cl, *tl;
746         int error;
747 
748         if (cred) {
749                 /*
750                  * Dealing with USB IO specific behavior
751                  */
752                 cl = aa_get_newest_cred_label(cred);
753                 tl = aa_get_task_label(target);
754                 error = aa_may_signal(cl, tl, sig);
755                 aa_put_label(cl);
756                 aa_put_label(tl);
757                 return error;
758         }
759 
760         cl = __begin_current_label_crit_section();
761         tl = aa_get_task_label(target);
762         error = aa_may_signal(cl, tl, sig);
763         aa_put_label(tl);
764         __end_current_label_crit_section(cl);
765 
766         return error;
767 }
768 
769 /**
770  * apparmor_sk_alloc_security - allocate and attach the sk_security field
771  */
772 static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
773 {
774         struct aa_sk_ctx *ctx;
775 
776         ctx = kzalloc(sizeof(*ctx), flags);
777         if (!ctx)
778                 return -ENOMEM;
779 
780         SK_CTX(sk) = ctx;
781 
782         return 0;
783 }
784 
785 /**
786  * apparmor_sk_free_security - free the sk_security field
787  */
788 static void apparmor_sk_free_security(struct sock *sk)
789 {
790         struct aa_sk_ctx *ctx = SK_CTX(sk);
791 
792         SK_CTX(sk) = NULL;
793         aa_put_label(ctx->label);
794         aa_put_label(ctx->peer);
795         kfree(ctx);
796 }
797 
798 /**
799  * apparmor_clone_security - clone the sk_security field
800  */
801 static void apparmor_sk_clone_security(const struct sock *sk,
802                                        struct sock *newsk)
803 {
804         struct aa_sk_ctx *ctx = SK_CTX(sk);
805         struct aa_sk_ctx *new = SK_CTX(newsk);
806 
807         new->label = aa_get_label(ctx->label);
808         new->peer = aa_get_label(ctx->peer);
809 }
810 
811 /**
812  * apparmor_socket_create - check perms before creating a new socket
813  */
814 static int apparmor_socket_create(int family, int type, int protocol, int kern)
815 {
816         struct aa_label *label;
817         int error = 0;
818 
819         AA_BUG(in_interrupt());
820 
821         label = begin_current_label_crit_section();
822         if (!(kern || unconfined(label)))
823                 error = af_select(family,
824                                   create_perm(label, family, type, protocol),
825                                   aa_af_perm(label, OP_CREATE, AA_MAY_CREATE,
826                                              family, type, protocol));
827         end_current_label_crit_section(label);
828 
829         return error;
830 }
831 
832 /**
833  * apparmor_socket_post_create - setup the per-socket security struct
834  *
835  * Note:
836  * -   kernel sockets currently labeled unconfined but we may want to
837  *     move to a special kernel label
838  * -   socket may not have sk here if created with sock_create_lite or
839  *     sock_alloc. These should be accept cases which will be handled in
840  *     sock_graft.
841  */
842 static int apparmor_socket_post_create(struct socket *sock, int family,
843                                        int type, int protocol, int kern)
844 {
845         struct aa_label *label;
846 
847         if (kern) {
848                 struct aa_ns *ns = aa_get_current_ns();
849 
850                 label = aa_get_label(ns_unconfined(ns));
851                 aa_put_ns(ns);
852         } else
853                 label = aa_get_current_label();
854 
855         if (sock->sk) {
856                 struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
857 
858                 aa_put_label(ctx->label);
859                 ctx->label = aa_get_label(label);
860         }
861         aa_put_label(label);
862 
863         return 0;
864 }
865 
866 /**
867  * apparmor_socket_bind - check perms before bind addr to socket
868  */
869 static int apparmor_socket_bind(struct socket *sock,
870                                 struct sockaddr *address, int addrlen)
871 {
872         AA_BUG(!sock);
873         AA_BUG(!sock->sk);
874         AA_BUG(!address);
875         AA_BUG(in_interrupt());
876 
877         return af_select(sock->sk->sk_family,
878                          bind_perm(sock, address, addrlen),
879                          aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk));
880 }
881 
882 /**
883  * apparmor_socket_connect - check perms before connecting @sock to @address
884  */
885 static int apparmor_socket_connect(struct socket *sock,
886                                    struct sockaddr *address, int addrlen)
887 {
888         AA_BUG(!sock);
889         AA_BUG(!sock->sk);
890         AA_BUG(!address);
891         AA_BUG(in_interrupt());
892 
893         return af_select(sock->sk->sk_family,
894                          connect_perm(sock, address, addrlen),
895                          aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk));
896 }
897 
898 /**
899  * apparmor_socket_list - check perms before allowing listen
900  */
901 static int apparmor_socket_listen(struct socket *sock, int backlog)
902 {
903         AA_BUG(!sock);
904         AA_BUG(!sock->sk);
905         AA_BUG(in_interrupt());
906 
907         return af_select(sock->sk->sk_family,
908                          listen_perm(sock, backlog),
909                          aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk));
910 }
911 
912 /**
913  * apparmor_socket_accept - check perms before accepting a new connection.
914  *
915  * Note: while @newsock is created and has some information, the accept
916  *       has not been done.
917  */
918 static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
919 {
920         AA_BUG(!sock);
921         AA_BUG(!sock->sk);
922         AA_BUG(!newsock);
923         AA_BUG(in_interrupt());
924 
925         return af_select(sock->sk->sk_family,
926                          accept_perm(sock, newsock),
927                          aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk));
928 }
929 
930 static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock,
931                             struct msghdr *msg, int size)
932 {
933         AA_BUG(!sock);
934         AA_BUG(!sock->sk);
935         AA_BUG(!msg);
936         AA_BUG(in_interrupt());
937 
938         return af_select(sock->sk->sk_family,
939                          msg_perm(op, request, sock, msg, size),
940                          aa_sk_perm(op, request, sock->sk));
941 }
942 
943 /**
944  * apparmor_socket_sendmsg - check perms before sending msg to another socket
945  */
946 static int apparmor_socket_sendmsg(struct socket *sock,
947                                    struct msghdr *msg, int size)
948 {
949         return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size);
950 }
951 
952 /**
953  * apparmor_socket_recvmsg - check perms before receiving a message
954  */
955 static int apparmor_socket_recvmsg(struct socket *sock,
956                                    struct msghdr *msg, int size, int flags)
957 {
958         return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size);
959 }
960 
961 /* revaliation, get/set attr, shutdown */
962 static int aa_sock_perm(const char *op, u32 request, struct socket *sock)
963 {
964         AA_BUG(!sock);
965         AA_BUG(!sock->sk);
966         AA_BUG(in_interrupt());
967 
968         return af_select(sock->sk->sk_family,
969                          sock_perm(op, request, sock),
970                          aa_sk_perm(op, request, sock->sk));
971 }
972 
973 /**
974  * apparmor_socket_getsockname - check perms before getting the local address
975  */
976 static int apparmor_socket_getsockname(struct socket *sock)
977 {
978         return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock);
979 }
980 
981 /**
982  * apparmor_socket_getpeername - check perms before getting remote address
983  */
984 static int apparmor_socket_getpeername(struct socket *sock)
985 {
986         return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock);
987 }
988 
989 /* revaliation, get/set attr, opt */
990 static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock,
991                             int level, int optname)
992 {
993         AA_BUG(!sock);
994         AA_BUG(!sock->sk);
995         AA_BUG(in_interrupt());
996 
997         return af_select(sock->sk->sk_family,
998                          opt_perm(op, request, sock, level, optname),
999                          aa_sk_perm(op, request, sock->sk));
1000 }
1001 
1002 /**
1003  * apparmor_getsockopt - check perms before getting socket options
1004  */
1005 static int apparmor_socket_getsockopt(struct socket *sock, int level,
1006                                       int optname)
1007 {
1008         return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock,
1009                                 level, optname);
1010 }
1011 
1012 /**
1013  * apparmor_setsockopt - check perms before setting socket options
1014  */
1015 static int apparmor_socket_setsockopt(struct socket *sock, int level,
1016                                       int optname)
1017 {
1018         return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock,
1019                                 level, optname);
1020 }
1021 
1022 /**
1023  * apparmor_socket_shutdown - check perms before shutting down @sock conn
1024  */
1025 static int apparmor_socket_shutdown(struct socket *sock, int how)
1026 {
1027         return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
1028 }
1029 
1030 #ifdef CONFIG_NETWORK_SECMARK
1031 /**
1032  * apparmor_socket_sock_recv_skb - check perms before associating skb to sk
1033  *
1034  * Note: can not sleep may be called with locks held
1035  *
1036  * dont want protocol specific in __skb_recv_datagram()
1037  * to deny an incoming connection  socket_sock_rcv_skb()
1038  */
1039 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
1040 {
1041         struct aa_sk_ctx *ctx = SK_CTX(sk);
1042 
1043         if (!skb->secmark)
1044                 return 0;
1045 
1046         return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE,
1047                                       skb->secmark, sk);
1048 }
1049 #endif
1050 
1051 
1052 static struct aa_label *sk_peer_label(struct sock *sk)
1053 {
1054         struct aa_sk_ctx *ctx = SK_CTX(sk);
1055 
1056         if (ctx->peer)
1057                 return ctx->peer;
1058 
1059         return ERR_PTR(-ENOPROTOOPT);
1060 }
1061 
1062 /**
1063  * apparmor_socket_getpeersec_stream - get security context of peer
1064  *
1065  * Note: for tcp only valid if using ipsec or cipso on lan
1066  */
1067 static int apparmor_socket_getpeersec_stream(struct socket *sock,
1068                                              char __user *optval,
1069                                              int __user *optlen,
1070                                              unsigned int len)
1071 {
1072         char *name;
1073         int slen, error = 0;
1074         struct aa_label *label;
1075         struct aa_label *peer;
1076 
1077         label = begin_current_label_crit_section();
1078         peer = sk_peer_label(sock->sk);
1079         if (IS_ERR(peer)) {
1080                 error = PTR_ERR(peer);
1081                 goto done;
1082         }
1083         slen = aa_label_asxprint(&name, labels_ns(label), peer,
1084                                  FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
1085                                  FLAG_HIDDEN_UNCONFINED, GFP_KERNEL);
1086         /* don't include terminating \0 in slen, it breaks some apps */
1087         if (slen < 0) {
1088                 error = -ENOMEM;
1089         } else {
1090                 if (slen > len) {
1091                         error = -ERANGE;
1092                 } else if (copy_to_user(optval, name, slen)) {
1093                         error = -EFAULT;
1094                         goto out;
1095                 }
1096                 if (put_user(slen, optlen))
1097                         error = -EFAULT;
1098 out:
1099                 kfree(name);
1100 
1101         }
1102 
1103 done:
1104         end_current_label_crit_section(label);
1105 
1106         return error;
1107 }
1108 
1109 /**
1110  * apparmor_socket_getpeersec_dgram - get security label of packet
1111  * @sock: the peer socket
1112  * @skb: packet data
1113  * @secid: pointer to where to put the secid of the packet
1114  *
1115  * Sets the netlabel socket state on sk from parent
1116  */
1117 static int apparmor_socket_getpeersec_dgram(struct socket *sock,
1118                                             struct sk_buff *skb, u32 *secid)
1119 
1120 {
1121         /* TODO: requires secid support */
1122         return -ENOPROTOOPT;
1123 }
1124 
1125 /**
1126  * apparmor_sock_graft - Initialize newly created socket
1127  * @sk: child sock
1128  * @parent: parent socket
1129  *
1130  * Note: could set off of SOCK_CTX(parent) but need to track inode and we can
1131  *       just set sk security information off of current creating process label
1132  *       Labeling of sk for accept case - probably should be sock based
1133  *       instead of task, because of the case where an implicitly labeled
1134  *       socket is shared by different tasks.
1135  */
1136 static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
1137 {
1138         struct aa_sk_ctx *ctx = SK_CTX(sk);
1139 
1140         if (!ctx->label)
1141                 ctx->label = aa_get_current_label();
1142 }
1143 
1144 #ifdef CONFIG_NETWORK_SECMARK
1145 static int apparmor_inet_conn_request(struct sock *sk, struct sk_buff *skb,
1146                                       struct request_sock *req)
1147 {
1148         struct aa_sk_ctx *ctx = SK_CTX(sk);
1149 
1150         if (!skb->secmark)
1151                 return 0;
1152 
1153         return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT,
1154                                       skb->secmark, sk);
1155 }
1156 #endif
1157 
1158 /*
1159  * The cred blob is a pointer to, not an instance of, an aa_task_ctx.
1160  */
1161 struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
1162         .lbs_cred = sizeof(struct aa_task_ctx *),
1163         .lbs_file = sizeof(struct aa_file_ctx),
1164         .lbs_task = sizeof(struct aa_task_ctx),
1165 };
1166 
1167 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
1168         LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
1169         LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
1170         LSM_HOOK_INIT(capget, apparmor_capget),
1171         LSM_HOOK_INIT(capable, apparmor_capable),
1172 
1173         LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
1174         LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
1175         LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
1176 
1177         LSM_HOOK_INIT(path_link, apparmor_path_link),
1178         LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
1179         LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
1180         LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
1181         LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
1182         LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
1183         LSM_HOOK_INIT(path_rename, apparmor_path_rename),
1184         LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
1185         LSM_HOOK_INIT(path_chown, apparmor_path_chown),
1186         LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
1187         LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
1188 
1189         LSM_HOOK_INIT(file_open, apparmor_file_open),
1190         LSM_HOOK_INIT(file_receive, apparmor_file_receive),
1191         LSM_HOOK_INIT(file_permission, apparmor_file_permission),
1192         LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
1193         LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
1194         LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
1195         LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
1196         LSM_HOOK_INIT(file_lock, apparmor_file_lock),
1197 
1198         LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
1199         LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
1200 
1201         LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
1202         LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
1203         LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
1204 
1205         LSM_HOOK_INIT(socket_create, apparmor_socket_create),
1206         LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
1207         LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
1208         LSM_HOOK_INIT(socket_connect, apparmor_socket_connect),
1209         LSM_HOOK_INIT(socket_listen, apparmor_socket_listen),
1210         LSM_HOOK_INIT(socket_accept, apparmor_socket_accept),
1211         LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg),
1212         LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg),
1213         LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname),
1214         LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername),
1215         LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
1216         LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
1217         LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
1218 #ifdef CONFIG_NETWORK_SECMARK
1219         LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
1220 #endif
1221         LSM_HOOK_INIT(socket_getpeersec_stream,
1222                       apparmor_socket_getpeersec_stream),
1223         LSM_HOOK_INIT(socket_getpeersec_dgram,
1224                       apparmor_socket_getpeersec_dgram),
1225         LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
1226 #ifdef CONFIG_NETWORK_SECMARK
1227         LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
1228 #endif
1229 
1230         LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
1231         LSM_HOOK_INIT(cred_free, apparmor_cred_free),
1232         LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
1233         LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
1234 
1235         LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds),
1236         LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
1237         LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
1238 
1239         LSM_HOOK_INIT(task_free, apparmor_task_free),
1240         LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
1241         LSM_HOOK_INIT(task_getsecid, apparmor_task_getsecid),
1242         LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
1243         LSM_HOOK_INIT(task_kill, apparmor_task_kill),
1244 
1245 #ifdef CONFIG_AUDIT
1246         LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
1247         LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
1248         LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
1249         LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
1250 #endif
1251 
1252         LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
1253         LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
1254         LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
1255 };
1256 
1257 /*
1258  * AppArmor sysfs module parameters
1259  */
1260 
1261 static int param_set_aabool(const char *val, const struct kernel_param *kp);
1262 static int param_get_aabool(char *buffer, const struct kernel_param *kp);
1263 #define param_check_aabool param_check_bool
1264 static const struct kernel_param_ops param_ops_aabool = {
1265         .flags = KERNEL_PARAM_OPS_FL_NOARG,
1266         .set = param_set_aabool,
1267         .get = param_get_aabool
1268 };
1269 
1270 static int param_set_aauint(const char *val, const struct kernel_param *kp);
1271 static int param_get_aauint(char *buffer, const struct kernel_param *kp);
1272 #define param_check_aauint param_check_uint
1273 static const struct kernel_param_ops param_ops_aauint = {
1274         .set = param_set_aauint,
1275         .get = param_get_aauint
1276 };
1277 
1278 static int param_set_aacompressionlevel(const char *val,
1279                                         const struct kernel_param *kp);
1280 static int param_get_aacompressionlevel(char *buffer,
1281                                         const struct kernel_param *kp);
1282 #define param_check_aacompressionlevel param_check_int
1283 static const struct kernel_param_ops param_ops_aacompressionlevel = {
1284         .set = param_set_aacompressionlevel,
1285         .get = param_get_aacompressionlevel
1286 };
1287 
1288 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
1289 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
1290 #define param_check_aalockpolicy param_check_bool
1291 static const struct kernel_param_ops param_ops_aalockpolicy = {
1292         .flags = KERNEL_PARAM_OPS_FL_NOARG,
1293         .set = param_set_aalockpolicy,
1294         .get = param_get_aalockpolicy
1295 };
1296 
1297 static int param_set_audit(const char *val, const struct kernel_param *kp);
1298 static int param_get_audit(char *buffer, const struct kernel_param *kp);
1299 
1300 static int param_set_mode(const char *val, const struct kernel_param *kp);
1301 static int param_get_mode(char *buffer, const struct kernel_param *kp);
1302 
1303 /* Flag values, also controllable via /sys/module/apparmor/parameters
1304  * We define special types as we want to do additional mediation.
1305  */
1306 
1307 /* AppArmor global enforcement switch - complain, enforce, kill */
1308 enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
1309 module_param_call(mode, param_set_mode, param_get_mode,
1310                   &aa_g_profile_mode, S_IRUSR | S_IWUSR);
1311 
1312 /* whether policy verification hashing is enabled */
1313 bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
1314 #ifdef CONFIG_SECURITY_APPARMOR_HASH
1315 module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
1316 #endif
1317 
1318 /* policy loaddata compression level */
1319 int aa_g_rawdata_compression_level = Z_DEFAULT_COMPRESSION;
1320 module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level,
1321                    aacompressionlevel, 0400);
1322 
1323 /* Debug mode */
1324 bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
1325 module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
1326 
1327 /* Audit mode */
1328 enum audit_mode aa_g_audit;
1329 module_param_call(audit, param_set_audit, param_get_audit,
1330                   &aa_g_audit, S_IRUSR | S_IWUSR);
1331 
1332 /* Determines if audit header is included in audited messages.  This
1333  * provides more context if the audit daemon is not running
1334  */
1335 bool aa_g_audit_header = true;
1336 module_param_named(audit_header, aa_g_audit_header, aabool,
1337                    S_IRUSR | S_IWUSR);
1338 
1339 /* lock out loading/removal of policy
1340  * TODO: add in at boot loading of policy, which is the only way to
1341  *       load policy, if lock_policy is set
1342  */
1343 bool aa_g_lock_policy;
1344 module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
1345                    S_IRUSR | S_IWUSR);
1346 
1347 /* Syscall logging mode */
1348 bool aa_g_logsyscall;
1349 module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
1350 
1351 /* Maximum pathname length before accesses will start getting rejected */
1352 unsigned int aa_g_path_max = 2 * PATH_MAX;
1353 module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR);
1354 
1355 /* Determines how paranoid loading of policy is and how much verification
1356  * on the loaded policy is done.
1357  * DEPRECATED: read only as strict checking of load is always done now
1358  * that none root users (user namespaces) can load policy.
1359  */
1360 bool aa_g_paranoid_load = true;
1361 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
1362 
1363 static int param_get_aaintbool(char *buffer, const struct kernel_param *kp);
1364 static int param_set_aaintbool(const char *val, const struct kernel_param *kp);
1365 #define param_check_aaintbool param_check_int
1366 static const struct kernel_param_ops param_ops_aaintbool = {
1367         .set = param_set_aaintbool,
1368         .get = param_get_aaintbool
1369 };
1370 /* Boot time disable flag */
1371 static int apparmor_enabled __lsm_ro_after_init = 1;
1372 module_param_named(enabled, apparmor_enabled, aaintbool, 0444);
1373 
1374 static int __init apparmor_enabled_setup(char *str)
1375 {
1376         unsigned long enabled;
1377         int error = kstrtoul(str, 0, &enabled);
1378         if (!error)
1379                 apparmor_enabled = enabled ? 1 : 0;
1380         return 1;
1381 }
1382 
1383 __setup("apparmor=", apparmor_enabled_setup);
1384 
1385 /* set global flag turning off the ability to load policy */
1386 static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
1387 {
1388         if (!apparmor_enabled)
1389                 return -EINVAL;
1390         if (apparmor_initialized && !policy_admin_capable(NULL))
1391                 return -EPERM;
1392         return param_set_bool(val, kp);
1393 }
1394 
1395 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
1396 {
1397         if (!apparmor_enabled)
1398                 return -EINVAL;
1399         if (apparmor_initialized && !policy_view_capable(NULL))
1400                 return -EPERM;
1401         return param_get_bool(buffer, kp);
1402 }
1403 
1404 static int param_set_aabool(const char *val, const struct kernel_param *kp)
1405 {
1406         if (!apparmor_enabled)
1407                 return -EINVAL;
1408         if (apparmor_initialized && !policy_admin_capable(NULL))
1409                 return -EPERM;
1410         return param_set_bool(val, kp);
1411 }
1412 
1413 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
1414 {
1415         if (!apparmor_enabled)
1416                 return -EINVAL;
1417         if (apparmor_initialized && !policy_view_capable(NULL))
1418                 return -EPERM;
1419         return param_get_bool(buffer, kp);
1420 }
1421 
1422 static int param_set_aauint(const char *val, const struct kernel_param *kp)
1423 {
1424         int error;
1425 
1426         if (!apparmor_enabled)
1427                 return -EINVAL;
1428         /* file is ro but enforce 2nd line check */
1429         if (apparmor_initialized)
1430                 return -EPERM;
1431 
1432         error = param_set_uint(val, kp);
1433         aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer));
1434         pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
1435 
1436         return error;
1437 }
1438 
1439 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
1440 {
1441         if (!apparmor_enabled)
1442                 return -EINVAL;
1443         if (apparmor_initialized && !policy_view_capable(NULL))
1444                 return -EPERM;
1445         return param_get_uint(buffer, kp);
1446 }
1447 
1448 /* Can only be set before AppArmor is initialized (i.e. on boot cmdline). */
1449 static int param_set_aaintbool(const char *val, const struct kernel_param *kp)
1450 {
1451         struct kernel_param kp_local;
1452         bool value;
1453         int error;
1454 
1455         if (apparmor_initialized)
1456                 return -EPERM;
1457 
1458         /* Create local copy, with arg pointing to bool type. */
1459         value = !!*((int *)kp->arg);
1460         memcpy(&kp_local, kp, sizeof(kp_local));
1461         kp_local.arg = &value;
1462 
1463         error = param_set_bool(val, &kp_local);
1464         if (!error)
1465                 *((int *)kp->arg) = *((bool *)kp_local.arg);
1466         return error;
1467 }
1468 
1469 /*
1470  * To avoid changing /sys/module/apparmor/parameters/enabled from Y/N to
1471  * 1/0, this converts the "int that is actually bool" back to bool for
1472  * display in the /sys filesystem, while keeping it "int" for the LSM
1473  * infrastructure.
1474  */
1475 static int param_get_aaintbool(char *buffer, const struct kernel_param *kp)
1476 {
1477         struct kernel_param kp_local;
1478         bool value;
1479 
1480         /* Create local copy, with arg pointing to bool type. */
1481         value = !!*((int *)kp->arg);
1482         memcpy(&kp_local, kp, sizeof(kp_local));
1483         kp_local.arg = &value;
1484 
1485         return param_get_bool(buffer, &kp_local);
1486 }
1487 
1488 static int param_set_aacompressionlevel(const char *val,
1489                                         const struct kernel_param *kp)
1490 {
1491         int error;
1492 
1493         if (!apparmor_enabled)
1494                 return -EINVAL;
1495         if (apparmor_initialized)
1496                 return -EPERM;
1497 
1498         error = param_set_int(val, kp);
1499 
1500         aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level,
1501                                                Z_NO_COMPRESSION,
1502                                                Z_BEST_COMPRESSION);
1503         pr_info("AppArmor: policy rawdata compression level set to %u\n",
1504                 aa_g_rawdata_compression_level);
1505 
1506         return error;
1507 }
1508 
1509 static int param_get_aacompressionlevel(char *buffer,
1510                                         const struct kernel_param *kp)
1511 {
1512         if (!apparmor_enabled)
1513                 return -EINVAL;
1514         if (apparmor_initialized && !policy_view_capable(NULL))
1515                 return -EPERM;
1516         return param_get_int(buffer, kp);
1517 }
1518 
1519 static int param_get_audit(char *buffer, const struct kernel_param *kp)
1520 {
1521         if (!apparmor_enabled)
1522                 return -EINVAL;
1523         if (apparmor_initialized && !policy_view_capable(NULL))
1524                 return -EPERM;
1525         return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
1526 }
1527 
1528 static int param_set_audit(const char *val, const struct kernel_param *kp)
1529 {
1530         int i;
1531 
1532         if (!apparmor_enabled)
1533                 return -EINVAL;
1534         if (!val)
1535                 return -EINVAL;
1536         if (apparmor_initialized && !policy_admin_capable(NULL))
1537                 return -EPERM;
1538 
1539         i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
1540         if (i < 0)
1541                 return -EINVAL;
1542 
1543         aa_g_audit = i;
1544         return 0;
1545 }
1546 
1547 static int param_get_mode(char *buffer, const struct kernel_param *kp)
1548 {
1549         if (!apparmor_enabled)
1550                 return -EINVAL;
1551         if (apparmor_initialized && !policy_view_capable(NULL))
1552                 return -EPERM;
1553 
1554         return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
1555 }
1556 
1557 static int param_set_mode(const char *val, const struct kernel_param *kp)
1558 {
1559         int i;
1560 
1561         if (!apparmor_enabled)
1562                 return -EINVAL;
1563         if (!val)
1564                 return -EINVAL;
1565         if (apparmor_initialized && !policy_admin_capable(NULL))
1566                 return -EPERM;
1567 
1568         i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
1569                          val);
1570         if (i < 0)
1571                 return -EINVAL;
1572 
1573         aa_g_profile_mode = i;
1574         return 0;
1575 }
1576 
1577 char *aa_get_buffer(bool in_atomic)
1578 {
1579         union aa_buffer *aa_buf;
1580         bool try_again = true;
1581         gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1582 
1583 retry:
1584         spin_lock(&aa_buffers_lock);
1585         if (buffer_count > reserve_count ||
1586             (in_atomic && !list_empty(&aa_global_buffers))) {
1587                 aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1588                                           list);
1589                 list_del(&aa_buf->list);
1590                 buffer_count--;
1591                 spin_unlock(&aa_buffers_lock);
1592                 return &aa_buf->buffer[0];
1593         }
1594         if (in_atomic) {
1595                 /*
1596                  * out of reserve buffers and in atomic context so increase
1597                  * how many buffers to keep in reserve
1598                  */
1599                 reserve_count++;
1600                 flags = GFP_ATOMIC;
1601         }
1602         spin_unlock(&aa_buffers_lock);
1603 
1604         if (!in_atomic)
1605                 might_sleep();
1606         aa_buf = kmalloc(aa_g_path_max, flags);
1607         if (!aa_buf) {
1608                 if (try_again) {
1609                         try_again = false;
1610                         goto retry;
1611                 }
1612                 pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n");
1613                 return NULL;
1614         }
1615         return &aa_buf->buffer[0];
1616 }
1617 
1618 void aa_put_buffer(char *buf)
1619 {
1620         union aa_buffer *aa_buf;
1621 
1622         if (!buf)
1623                 return;
1624         aa_buf = container_of(buf, union aa_buffer, buffer[0]);
1625 
1626         spin_lock(&aa_buffers_lock);
1627         list_add(&aa_buf->list, &aa_global_buffers);
1628         buffer_count++;
1629         spin_unlock(&aa_buffers_lock);
1630 }
1631 
1632 /*
1633  * AppArmor init functions
1634  */
1635 
1636 /**
1637  * set_init_ctx - set a task context and profile on the first task.
1638  *
1639  * TODO: allow setting an alternate profile than unconfined
1640  */
1641 static int __init set_init_ctx(void)
1642 {
1643         struct cred *cred = (__force struct cred *)current->real_cred;
1644 
1645         set_cred_label(cred, aa_get_label(ns_unconfined(root_ns)));
1646 
1647         return 0;
1648 }
1649 
1650 static void destroy_buffers(void)
1651 {
1652         union aa_buffer *aa_buf;
1653 
1654         spin_lock(&aa_buffers_lock);
1655         while (!list_empty(&aa_global_buffers)) {
1656                 aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1657                                          list);
1658                 list_del(&aa_buf->list);
1659                 spin_unlock(&aa_buffers_lock);
1660                 kfree(aa_buf);
1661                 spin_lock(&aa_buffers_lock);
1662         }
1663         spin_unlock(&aa_buffers_lock);
1664 }
1665 
1666 static int __init alloc_buffers(void)
1667 {
1668         union aa_buffer *aa_buf;
1669         int i, num;
1670 
1671         /*
1672          * A function may require two buffers at once. Usually the buffers are
1673          * used for a short period of time and are shared. On UP kernel buffers
1674          * two should be enough, with more CPUs it is possible that more
1675          * buffers will be used simultaneously. The preallocated pool may grow.
1676          * This preallocation has also the side-effect that AppArmor will be
1677          * disabled early at boot if aa_g_path_max is extremly high.
1678          */
1679         if (num_online_cpus() > 1)
1680                 num = 4 + RESERVE_COUNT;
1681         else
1682                 num = 2 + RESERVE_COUNT;
1683 
1684         for (i = 0; i < num; i++) {
1685 
1686                 aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL |
1687                                  __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1688                 if (!aa_buf) {
1689                         destroy_buffers();
1690                         return -ENOMEM;
1691                 }
1692                 aa_put_buffer(&aa_buf->buffer[0]);
1693         }
1694         return 0;
1695 }
1696 
1697 #ifdef CONFIG_SYSCTL
1698 static int apparmor_dointvec(struct ctl_table *table, int write,
1699                              void __user *buffer, size_t *lenp, loff_t *ppos)
1700 {
1701         if (!policy_admin_capable(NULL))
1702                 return -EPERM;
1703         if (!apparmor_enabled)
1704                 return -EINVAL;
1705 
1706         return proc_dointvec(table, write, buffer, lenp, ppos);
1707 }
1708 
1709 static struct ctl_path apparmor_sysctl_path[] = {
1710         { .procname = "kernel", },
1711         { }
1712 };
1713 
1714 static struct ctl_table apparmor_sysctl_table[] = {
1715         {
1716                 .procname       = "unprivileged_userns_apparmor_policy",
1717                 .data           = &unprivileged_userns_apparmor_policy,
1718                 .maxlen         = sizeof(int),
1719                 .mode           = 0600,
1720                 .proc_handler   = apparmor_dointvec,
1721         },
1722         { }
1723 };
1724 
1725 static int __init apparmor_init_sysctl(void)
1726 {
1727         return register_sysctl_paths(apparmor_sysctl_path,
1728                                      apparmor_sysctl_table) ? 0 : -ENOMEM;
1729 }
1730 #else
1731 static inline int apparmor_init_sysctl(void)
1732 {
1733         return 0;
1734 }
1735 #endif /* CONFIG_SYSCTL */
1736 
1737 #if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK)
1738 static unsigned int apparmor_ip_postroute(void *priv,
1739                                           struct sk_buff *skb,
1740                                           const struct nf_hook_state *state)
1741 {
1742         struct aa_sk_ctx *ctx;
1743         struct sock *sk;
1744 
1745         if (!skb->secmark)
1746                 return NF_ACCEPT;
1747 
1748         sk = skb_to_full_sk(skb);
1749         if (sk == NULL)
1750                 return NF_ACCEPT;
1751 
1752         ctx = SK_CTX(sk);
1753         if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
1754                                     skb->secmark, sk))
1755                 return NF_ACCEPT;
1756 
1757         return NF_DROP_ERR(-ECONNREFUSED);
1758 
1759 }
1760 
1761 static unsigned int apparmor_ipv4_postroute(void *priv,
1762                                             struct sk_buff *skb,
1763                                             const struct nf_hook_state *state)
1764 {
1765         return apparmor_ip_postroute(priv, skb, state);
1766 }
1767 
1768 #if IS_ENABLED(CONFIG_IPV6)
1769 static unsigned int apparmor_ipv6_postroute(void *priv,
1770                                             struct sk_buff *skb,
1771                                             const struct nf_hook_state *state)
1772 {
1773         return apparmor_ip_postroute(priv, skb, state);
1774 }
1775 #endif
1776 
1777 static const struct nf_hook_ops apparmor_nf_ops[] = {
1778         {
1779                 .hook =         apparmor_ipv4_postroute,
1780                 .pf =           NFPROTO_IPV4,
1781                 .hooknum =      NF_INET_POST_ROUTING,
1782                 .priority =     NF_IP_PRI_SELINUX_FIRST,
1783         },
1784 #if IS_ENABLED(CONFIG_IPV6)
1785         {
1786                 .hook =         apparmor_ipv6_postroute,
1787                 .pf =           NFPROTO_IPV6,
1788                 .hooknum =      NF_INET_POST_ROUTING,
1789                 .priority =     NF_IP6_PRI_SELINUX_FIRST,
1790         },
1791 #endif
1792 };
1793 
1794 static int __net_init apparmor_nf_register(struct net *net)
1795 {
1796         int ret;
1797 
1798         ret = nf_register_net_hooks(net, apparmor_nf_ops,
1799                                     ARRAY_SIZE(apparmor_nf_ops));
1800         return ret;
1801 }
1802 
1803 static void __net_exit apparmor_nf_unregister(struct net *net)
1804 {
1805         nf_unregister_net_hooks(net, apparmor_nf_ops,
1806                                 ARRAY_SIZE(apparmor_nf_ops));
1807 }
1808 
1809 static struct pernet_operations apparmor_net_ops = {
1810         .init = apparmor_nf_register,
1811         .exit = apparmor_nf_unregister,
1812 };
1813 
1814 static int __init apparmor_nf_ip_init(void)
1815 {
1816         int err;
1817 
1818         if (!apparmor_enabled)
1819                 return 0;
1820 
1821         err = register_pernet_subsys(&apparmor_net_ops);
1822         if (err)
1823                 panic("Apparmor: register_pernet_subsys: error %d\n", err);
1824 
1825         return 0;
1826 }
1827 __initcall(apparmor_nf_ip_init);
1828 #endif
1829 
1830 static int __init apparmor_init(void)
1831 {
1832         int error;
1833 
1834         aa_secids_init();
1835 
1836         error = aa_setup_dfa_engine();
1837         if (error) {
1838                 AA_ERROR("Unable to setup dfa engine\n");
1839                 goto alloc_out;
1840         }
1841 
1842         error = aa_alloc_root_ns();
1843         if (error) {
1844                 AA_ERROR("Unable to allocate default profile namespace\n");
1845                 goto alloc_out;
1846         }
1847 
1848         error = apparmor_init_sysctl();
1849         if (error) {
1850                 AA_ERROR("Unable to register sysctls\n");
1851                 goto alloc_out;
1852 
1853         }
1854 
1855         error = alloc_buffers();
1856         if (error) {
1857                 AA_ERROR("Unable to allocate work buffers\n");
1858                 goto alloc_out;
1859         }
1860 
1861         error = set_init_ctx();
1862         if (error) {
1863                 AA_ERROR("Failed to set context on init task\n");
1864                 aa_free_root_ns();
1865                 goto buffers_out;
1866         }
1867         security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
1868                                 "apparmor");
1869 
1870         /* Report that AppArmor successfully initialized */
1871         apparmor_initialized = 1;
1872         if (aa_g_profile_mode == APPARMOR_COMPLAIN)
1873                 aa_info_message("AppArmor initialized: complain mode enabled");
1874         else if (aa_g_profile_mode == APPARMOR_KILL)
1875                 aa_info_message("AppArmor initialized: kill mode enabled");
1876         else
1877                 aa_info_message("AppArmor initialized");
1878 
1879         return error;
1880 
1881 buffers_out:
1882         destroy_buffers();
1883 alloc_out:
1884         aa_destroy_aafs();
1885         aa_teardown_dfa_engine();
1886 
1887         apparmor_enabled = false;
1888         return error;
1889 }
1890 
1891 DEFINE_LSM(apparmor) = {
1892         .name = "apparmor",
1893         .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
1894         .enabled = &apparmor_enabled,
1895         .blobs = &apparmor_blob_sizes,
1896         .init = apparmor_init,
1897 };
1898 

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