Root/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 */
39int apparmor_initialized __initdata;
40
41/*
42 * LSM hook functions
43 */
44
45/*
46 * free the associated aa_task_cxt and put its profiles
47 */
48static 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 */
57static 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 */
71static 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 */
87static 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
95static 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
105static 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 */
115static 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
138static 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 */
161static 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 */
184static 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 */
202static 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 */
222static 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 */
247static 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
258static 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
263static 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
270static 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
275static 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
281static int apparmor_path_truncate(struct path *path)
282{
283    struct path_cond cond = { path->dentry->d_inode->i_uid,
284                  path->dentry->d_inode->i_mode
285    };
286
287    if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
288        return 0;
289
290    return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
291               &cond);
292}
293
294static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
295                 const char *old_name)
296{
297    return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
298                  S_IFLNK);
299}
300
301static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
302                  struct dentry *new_dentry)
303{
304    struct aa_profile *profile;
305    int error = 0;
306
307    if (!mediated_filesystem(old_dentry->d_inode))
308        return 0;
309
310    profile = aa_current_profile();
311    if (!unconfined(profile))
312        error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
313    return error;
314}
315
316static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
317                struct path *new_dir, struct dentry *new_dentry)
318{
319    struct aa_profile *profile;
320    int error = 0;
321
322    if (!mediated_filesystem(old_dentry->d_inode))
323        return 0;
324
325    profile = aa_current_profile();
326    if (!unconfined(profile)) {
327        struct path old_path = { old_dir->mnt, old_dentry };
328        struct path new_path = { new_dir->mnt, new_dentry };
329        struct path_cond cond = { old_dentry->d_inode->i_uid,
330                      old_dentry->d_inode->i_mode
331        };
332
333        error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
334                     MAY_READ | AA_MAY_META_READ | MAY_WRITE |
335                     AA_MAY_META_WRITE | AA_MAY_DELETE,
336                     &cond);
337        if (!error)
338            error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
339                         0, MAY_WRITE | AA_MAY_META_WRITE |
340                         AA_MAY_CREATE, &cond);
341
342    }
343    return error;
344}
345
346static int apparmor_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
347                   mode_t mode)
348{
349    if (!mediated_filesystem(dentry->d_inode))
350        return 0;
351
352    return common_perm_mnt_dentry(OP_CHMOD, mnt, dentry, AA_MAY_CHMOD);
353}
354
355static int apparmor_path_chown(struct path *path, uid_t uid, gid_t gid)
356{
357    struct path_cond cond = { path->dentry->d_inode->i_uid,
358                   path->dentry->d_inode->i_mode
359    };
360
361    if (!mediated_filesystem(path->dentry->d_inode))
362        return 0;
363
364    return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
365}
366
367static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
368{
369    if (!mediated_filesystem(dentry->d_inode))
370        return 0;
371
372    return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry,
373                      AA_MAY_META_READ);
374}
375
376static int apparmor_dentry_open(struct file *file, const struct cred *cred)
377{
378    struct aa_file_cxt *fcxt = file->f_security;
379    struct aa_profile *profile;
380    int error = 0;
381
382    if (!mediated_filesystem(file->f_path.dentry->d_inode))
383        return 0;
384
385    /* If in exec, permission is handled by bprm hooks.
386     * Cache permissions granted by the previous exec check, with
387     * implicit read and executable mmap which are required to
388     * actually execute the image.
389     */
390    if (current->in_execve) {
391        fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
392        return 0;
393    }
394
395    profile = aa_cred_profile(cred);
396    if (!unconfined(profile)) {
397        struct inode *inode = file->f_path.dentry->d_inode;
398        struct path_cond cond = { inode->i_uid, inode->i_mode };
399
400        error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
401                     aa_map_file_to_perms(file), &cond);
402        /* todo cache full allowed permissions set and state */
403        fcxt->allow = aa_map_file_to_perms(file);
404    }
405
406    return error;
407}
408
409static int apparmor_file_alloc_security(struct file *file)
410{
411    /* freed by apparmor_file_free_security */
412    file->f_security = aa_alloc_file_context(GFP_KERNEL);
413    if (!file->f_security)
414        return -ENOMEM;
415    return 0;
416
417}
418
419static void apparmor_file_free_security(struct file *file)
420{
421    struct aa_file_cxt *cxt = file->f_security;
422
423    aa_free_file_context(cxt);
424}
425
426static int common_file_perm(int op, struct file *file, u32 mask)
427{
428    struct aa_file_cxt *fcxt = file->f_security;
429    struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
430    int error = 0;
431
432    BUG_ON(!fprofile);
433
434    if (!file->f_path.mnt ||
435        !mediated_filesystem(file->f_path.dentry->d_inode))
436        return 0;
437
438    profile = __aa_current_profile();
439
440    /* revalidate access, if task is unconfined, or the cached cred
441     * doesn't match or if the request is for more permissions than
442     * was granted.
443     *
444     * Note: the test for !unconfined(fprofile) is to handle file
445     * delegation from unconfined tasks
446     */
447    if (!unconfined(profile) && !unconfined(fprofile) &&
448        ((fprofile != profile) || (mask & ~fcxt->allow)))
449        error = aa_file_perm(op, profile, file, mask);
450
451    return error;
452}
453
454static int apparmor_file_permission(struct file *file, int mask)
455{
456    return common_file_perm(OP_FPERM, file, mask);
457}
458
459static int apparmor_file_lock(struct file *file, unsigned int cmd)
460{
461    u32 mask = AA_MAY_LOCK;
462
463    if (cmd == F_WRLCK)
464        mask |= MAY_WRITE;
465
466    return common_file_perm(OP_FLOCK, file, mask);
467}
468
469static int common_mmap(int op, struct file *file, unsigned long prot,
470               unsigned long flags)
471{
472    struct dentry *dentry;
473    int mask = 0;
474
475    if (!file || !file->f_security)
476        return 0;
477
478    if (prot & PROT_READ)
479        mask |= MAY_READ;
480    /*
481     * Private mappings don't require write perms since they don't
482     * write back to the files
483     */
484    if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
485        mask |= MAY_WRITE;
486    if (prot & PROT_EXEC)
487        mask |= AA_EXEC_MMAP;
488
489    dentry = file->f_path.dentry;
490    return common_file_perm(op, file, mask);
491}
492
493static int apparmor_file_mmap(struct file *file, unsigned long reqprot,
494                  unsigned long prot, unsigned long flags,
495                  unsigned long addr, unsigned long addr_only)
496{
497    int rc = 0;
498
499    /* do DAC check */
500    rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
501    if (rc || addr_only)
502        return rc;
503
504    return common_mmap(OP_FMMAP, file, prot, flags);
505}
506
507static int apparmor_file_mprotect(struct vm_area_struct *vma,
508                  unsigned long reqprot, unsigned long prot)
509{
510    return common_mmap(OP_FMPROT, vma->vm_file, prot,
511               !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
512}
513
514static int apparmor_getprocattr(struct task_struct *task, char *name,
515                char **value)
516{
517    int error = -ENOENT;
518    struct aa_profile *profile;
519    /* released below */
520    const struct cred *cred = get_task_cred(task);
521    struct aa_task_cxt *cxt = cred->security;
522    profile = aa_cred_profile(cred);
523
524    if (strcmp(name, "current") == 0)
525        error = aa_getprocattr(aa_newest_version(cxt->profile),
526                       value);
527    else if (strcmp(name, "prev") == 0 && cxt->previous)
528        error = aa_getprocattr(aa_newest_version(cxt->previous),
529                       value);
530    else if (strcmp(name, "exec") == 0 && cxt->onexec)
531        error = aa_getprocattr(aa_newest_version(cxt->onexec),
532                       value);
533    else
534        error = -EINVAL;
535
536    put_cred(cred);
537
538    return error;
539}
540
541static int apparmor_setprocattr(struct task_struct *task, char *name,
542                void *value, size_t size)
543{
544    char *command, *args = value;
545    size_t arg_size;
546    int error;
547
548    if (size == 0)
549        return -EINVAL;
550    /* args points to a PAGE_SIZE buffer, AppArmor requires that
551     * the buffer must be null terminated or have size <= PAGE_SIZE -1
552     * so that AppArmor can null terminate them
553     */
554    if (args[size - 1] != '\0') {
555        if (size == PAGE_SIZE)
556            return -EINVAL;
557        args[size] = '\0';
558    }
559
560    /* task can only write its own attributes */
561    if (current != task)
562        return -EACCES;
563
564    args = value;
565    args = strim(args);
566    command = strsep(&args, " ");
567    if (!args)
568        return -EINVAL;
569    args = skip_spaces(args);
570    if (!*args)
571        return -EINVAL;
572
573    arg_size = size - (args - (char *) value);
574    if (strcmp(name, "current") == 0) {
575        if (strcmp(command, "changehat") == 0) {
576            error = aa_setprocattr_changehat(args, arg_size,
577                             !AA_DO_TEST);
578        } else if (strcmp(command, "permhat") == 0) {
579            error = aa_setprocattr_changehat(args, arg_size,
580                             AA_DO_TEST);
581        } else if (strcmp(command, "changeprofile") == 0) {
582            error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
583                                 !AA_DO_TEST);
584        } else if (strcmp(command, "permprofile") == 0) {
585            error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
586                                 AA_DO_TEST);
587        } else if (strcmp(command, "permipc") == 0) {
588            error = aa_setprocattr_permipc(args);
589        } else {
590            struct common_audit_data sa;
591            COMMON_AUDIT_DATA_INIT(&sa, NONE);
592            sa.aad.op = OP_SETPROCATTR;
593            sa.aad.info = name;
594            sa.aad.error = -EINVAL;
595            return aa_audit(AUDIT_APPARMOR_DENIED, NULL, GFP_KERNEL,
596                    &sa, NULL);
597        }
598    } else if (strcmp(name, "exec") == 0) {
599        error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
600                             !AA_DO_TEST);
601    } else {
602        /* only support the "current" and "exec" process attributes */
603        return -EINVAL;
604    }
605    if (!error)
606        error = size;
607    return error;
608}
609
610static int apparmor_task_setrlimit(struct task_struct *task,
611        unsigned int resource, struct rlimit *new_rlim)
612{
613    struct aa_profile *profile = aa_current_profile();
614    int error = 0;
615
616    if (!unconfined(profile))
617        error = aa_task_setrlimit(profile, task, resource, new_rlim);
618
619    return error;
620}
621
622static struct security_operations apparmor_ops = {
623    .name = "apparmor",
624
625    .ptrace_access_check = apparmor_ptrace_access_check,
626    .ptrace_traceme = apparmor_ptrace_traceme,
627    .capget = apparmor_capget,
628    .capable = apparmor_capable,
629
630    .path_link = apparmor_path_link,
631    .path_unlink = apparmor_path_unlink,
632    .path_symlink = apparmor_path_symlink,
633    .path_mkdir = apparmor_path_mkdir,
634    .path_rmdir = apparmor_path_rmdir,
635    .path_mknod = apparmor_path_mknod,
636    .path_rename = apparmor_path_rename,
637    .path_chmod = apparmor_path_chmod,
638    .path_chown = apparmor_path_chown,
639    .path_truncate = apparmor_path_truncate,
640    .dentry_open = apparmor_dentry_open,
641    .inode_getattr = apparmor_inode_getattr,
642
643    .file_permission = apparmor_file_permission,
644    .file_alloc_security = apparmor_file_alloc_security,
645    .file_free_security = apparmor_file_free_security,
646    .file_mmap = apparmor_file_mmap,
647    .file_mprotect = apparmor_file_mprotect,
648    .file_lock = apparmor_file_lock,
649
650    .getprocattr = apparmor_getprocattr,
651    .setprocattr = apparmor_setprocattr,
652
653    .cred_alloc_blank = apparmor_cred_alloc_blank,
654    .cred_free = apparmor_cred_free,
655    .cred_prepare = apparmor_cred_prepare,
656    .cred_transfer = apparmor_cred_transfer,
657
658    .bprm_set_creds = apparmor_bprm_set_creds,
659    .bprm_committing_creds = apparmor_bprm_committing_creds,
660    .bprm_committed_creds = apparmor_bprm_committed_creds,
661    .bprm_secureexec = apparmor_bprm_secureexec,
662
663    .task_setrlimit = apparmor_task_setrlimit,
664};
665
666/*
667 * AppArmor sysfs module parameters
668 */
669
670static int param_set_aabool(const char *val, const struct kernel_param *kp);
671static int param_get_aabool(char *buffer, const struct kernel_param *kp);
672#define param_check_aabool(name, p) __param_check(name, p, int)
673static struct kernel_param_ops param_ops_aabool = {
674    .set = param_set_aabool,
675    .get = param_get_aabool
676};
677
678static int param_set_aauint(const char *val, const struct kernel_param *kp);
679static int param_get_aauint(char *buffer, const struct kernel_param *kp);
680#define param_check_aauint(name, p) __param_check(name, p, int)
681static struct kernel_param_ops param_ops_aauint = {
682    .set = param_set_aauint,
683    .get = param_get_aauint
684};
685
686static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
687static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
688#define param_check_aalockpolicy(name, p) __param_check(name, p, int)
689static struct kernel_param_ops param_ops_aalockpolicy = {
690    .set = param_set_aalockpolicy,
691    .get = param_get_aalockpolicy
692};
693
694static int param_set_audit(const char *val, struct kernel_param *kp);
695static int param_get_audit(char *buffer, struct kernel_param *kp);
696#define param_check_audit(name, p) __param_check(name, p, int)
697
698static int param_set_mode(const char *val, struct kernel_param *kp);
699static int param_get_mode(char *buffer, struct kernel_param *kp);
700#define param_check_mode(name, p) __param_check(name, p, int)
701
702/* Flag values, also controllable via /sys/module/apparmor/parameters
703 * We define special types as we want to do additional mediation.
704 */
705
706/* AppArmor global enforcement switch - complain, enforce, kill */
707enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
708module_param_call(mode, param_set_mode, param_get_mode,
709          &aa_g_profile_mode, S_IRUSR | S_IWUSR);
710
711/* Debug mode */
712int aa_g_debug;
713module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
714
715/* Audit mode */
716enum audit_mode aa_g_audit;
717module_param_call(audit, param_set_audit, param_get_audit,
718          &aa_g_audit, S_IRUSR | S_IWUSR);
719
720/* Determines if audit header is included in audited messages. This
721 * provides more context if the audit daemon is not running
722 */
723int aa_g_audit_header = 1;
724module_param_named(audit_header, aa_g_audit_header, aabool,
725           S_IRUSR | S_IWUSR);
726
727/* lock out loading/removal of policy
728 * TODO: add in at boot loading of policy, which is the only way to
729 * load policy, if lock_policy is set
730 */
731int aa_g_lock_policy;
732module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
733           S_IRUSR | S_IWUSR);
734
735/* Syscall logging mode */
736int aa_g_logsyscall;
737module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
738
739/* Maximum pathname length before accesses will start getting rejected */
740unsigned int aa_g_path_max = 2 * PATH_MAX;
741module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);
742
743/* Determines how paranoid loading of policy is and how much verification
744 * on the loaded policy is done.
745 */
746int aa_g_paranoid_load = 1;
747module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
748           S_IRUSR | S_IWUSR);
749
750/* Boot time disable flag */
751static unsigned int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
752module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);
753
754static int __init apparmor_enabled_setup(char *str)
755{
756    unsigned long enabled;
757    int error = strict_strtoul(str, 0, &enabled);
758    if (!error)
759        apparmor_enabled = enabled ? 1 : 0;
760    return 1;
761}
762
763__setup("apparmor=", apparmor_enabled_setup);
764
765/* set global flag turning off the ability to load policy */
766static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
767{
768    if (!capable(CAP_MAC_ADMIN))
769        return -EPERM;
770    if (aa_g_lock_policy)
771        return -EACCES;
772    return param_set_bool(val, kp);
773}
774
775static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
776{
777    if (!capable(CAP_MAC_ADMIN))
778        return -EPERM;
779    return param_get_bool(buffer, kp);
780}
781
782static int param_set_aabool(const char *val, const struct kernel_param *kp)
783{
784    if (!capable(CAP_MAC_ADMIN))
785        return -EPERM;
786    return param_set_bool(val, kp);
787}
788
789static int param_get_aabool(char *buffer, const struct kernel_param *kp)
790{
791    if (!capable(CAP_MAC_ADMIN))
792        return -EPERM;
793    return param_get_bool(buffer, kp);
794}
795
796static int param_set_aauint(const char *val, const struct kernel_param *kp)
797{
798    if (!capable(CAP_MAC_ADMIN))
799        return -EPERM;
800    return param_set_uint(val, kp);
801}
802
803static int param_get_aauint(char *buffer, const struct kernel_param *kp)
804{
805    if (!capable(CAP_MAC_ADMIN))
806        return -EPERM;
807    return param_get_uint(buffer, kp);
808}
809
810static int param_get_audit(char *buffer, struct kernel_param *kp)
811{
812    if (!capable(CAP_MAC_ADMIN))
813        return -EPERM;
814
815    if (!apparmor_enabled)
816        return -EINVAL;
817
818    return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
819}
820
821static int param_set_audit(const char *val, struct kernel_param *kp)
822{
823    int i;
824    if (!capable(CAP_MAC_ADMIN))
825        return -EPERM;
826
827    if (!apparmor_enabled)
828        return -EINVAL;
829
830    if (!val)
831        return -EINVAL;
832
833    for (i = 0; i < AUDIT_MAX_INDEX; i++) {
834        if (strcmp(val, audit_mode_names[i]) == 0) {
835            aa_g_audit = i;
836            return 0;
837        }
838    }
839
840    return -EINVAL;
841}
842
843static int param_get_mode(char *buffer, struct kernel_param *kp)
844{
845    if (!capable(CAP_MAC_ADMIN))
846        return -EPERM;
847
848    if (!apparmor_enabled)
849        return -EINVAL;
850
851    return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
852}
853
854static int param_set_mode(const char *val, struct kernel_param *kp)
855{
856    int i;
857    if (!capable(CAP_MAC_ADMIN))
858        return -EPERM;
859
860    if (!apparmor_enabled)
861        return -EINVAL;
862
863    if (!val)
864        return -EINVAL;
865
866    for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
867        if (strcmp(val, profile_mode_names[i]) == 0) {
868            aa_g_profile_mode = i;
869            return 0;
870        }
871    }
872
873    return -EINVAL;
874}
875
876/*
877 * AppArmor init functions
878 */
879
880/**
881 * set_init_cxt - set a task context and profile on the first task.
882 *
883 * TODO: allow setting an alternate profile than unconfined
884 */
885static int __init set_init_cxt(void)
886{
887    struct cred *cred = (struct cred *)current->real_cred;
888    struct aa_task_cxt *cxt;
889
890    cxt = aa_alloc_task_context(GFP_KERNEL);
891    if (!cxt)
892        return -ENOMEM;
893
894    cxt->profile = aa_get_profile(root_ns->unconfined);
895    cred->security = cxt;
896
897    return 0;
898}
899
900static int __init apparmor_init(void)
901{
902    int error;
903
904    if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
905        aa_info_message("AppArmor disabled by boot time parameter");
906        apparmor_enabled = 0;
907        return 0;
908    }
909
910    error = aa_alloc_root_ns();
911    if (error) {
912        AA_ERROR("Unable to allocate default profile namespace\n");
913        goto alloc_out;
914    }
915
916    error = set_init_cxt();
917    if (error) {
918        AA_ERROR("Failed to set context on init task\n");
919        goto register_security_out;
920    }
921
922    error = register_security(&apparmor_ops);
923    if (error) {
924        AA_ERROR("Unable to register AppArmor\n");
925        goto register_security_out;
926    }
927
928    /* Report that AppArmor successfully initialized */
929    apparmor_initialized = 1;
930    if (aa_g_profile_mode == APPARMOR_COMPLAIN)
931        aa_info_message("AppArmor initialized: complain mode enabled");
932    else if (aa_g_profile_mode == APPARMOR_KILL)
933        aa_info_message("AppArmor initialized: kill mode enabled");
934    else
935        aa_info_message("AppArmor initialized");
936
937    return error;
938
939register_security_out:
940    aa_free_root_ns();
941
942alloc_out:
943    aa_destroy_aafs();
944
945    apparmor_enabled = 0;
946    return error;
947
948}
949
950security_initcall(apparmor_init);
951

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