security/apparmor/audit.c

   1 /*
   2  * AppArmor security module
   3  *
   4  * This file contains AppArmor auditing functions
   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/audit.h>
  16 #include <linux/socket.h>
  17
  18 #include "include/apparmor.h"
  19 #include "include/audit.h"
  20 #include "include/policy.h"
  21 #include "include/policy_ns.h"
  22 #include "include/secid.h"
  23
  24 const char *const audit_mode_names[] = {
  25         "normal",
  26         "quiet_denied",
  27         "quiet",
  28         "noquiet",
  29         "all"
  30 };
  31
  32 static const char *const aa_audit_type[] = {
  33         "AUDIT",
  34         "ALLOWED",
  35         "DENIED",
  36         "HINT",
  37         "STATUS",
  38         "ERROR",
  39         "KILLED",
  40         "AUTO"
  41 };
  42
  43 /*
  44  * Currently AppArmor auditing is fed straight into the audit framework.
  45  *
  46  * TODO:
  47  * netlink interface for complain mode
  48  * user auditing, - send user auditing to netlink interface
  49  * system control of whether user audit messages go to system log
  50  */
  51
  52 /**
  53  * audit_base - core AppArmor function.
  54  * @ab: audit buffer to fill (NOT NULL)
  55  * @ca: audit structure containing data to audit (NOT NULL)
  56  *
  57  * Record common AppArmor audit data from @sa
  58  */
  59 static void audit_pre(struct audit_buffer *ab, void *ca)
  60 {
  61         struct common_audit_data *sa = ca;
  62
  63         if (aa_g_audit_header) {
  64                 audit_log_format(ab, "apparmor=");
  65                 audit_log_string(ab, aa_audit_type[aad(sa)->type]);
  66         }
  67
  68         if (aad(sa)->op) {
  69                 audit_log_format(ab, " operation=");
  70                 audit_log_string(ab, aad(sa)->op);
  71         }
  72
  73         if (aad(sa)->info) {
  74                 audit_log_format(ab, " info=");
  75                 audit_log_string(ab, aad(sa)->info);
  76                 if (aad(sa)->error)
  77                         audit_log_format(ab, " error=%d", aad(sa)->error);
  78         }
  79
  80         if (aad(sa)->label) {
  81                 struct aa_label *label = aad(sa)->label;
  82
  83                 if (label_isprofile(label)) {
  84                         struct aa_profile *profile = labels_profile(label);
  85
  86                         if (profile->ns != root_ns) {
  87                                 audit_log_format(ab, " namespace=");
  88                                 audit_log_untrustedstring(ab,
  89                                                        profile->ns->base.hname);
  90                         }
  91                         audit_log_format(ab, " profile=");
  92                         audit_log_untrustedstring(ab, profile->base.hname);
  93                 } else {
  94                         audit_log_format(ab, " label=");
  95                         aa_label_xaudit(ab, root_ns, label, FLAG_VIEW_SUBNS,
  96                                         GFP_ATOMIC);
  97                 }
  98         }
  99
 100         if (aad(sa)->name) {
 101                 audit_log_format(ab, " name=");
 102                 audit_log_untrustedstring(ab, aad(sa)->name);
 103         }
 104 }
 105
 106 /**
 107  * aa_audit_msg - Log a message to the audit subsystem
 108  * @sa: audit event structure (NOT NULL)
 109  * @cb: optional callback fn for type specific fields (MAYBE NULL)
 110  */
 111 void aa_audit_msg(int type, struct common_audit_data *sa,
 112                   void (*cb) (struct audit_buffer *, void *))
 113 {
 114         aad(sa)->type = type;
 115         common_lsm_audit(sa, audit_pre, cb);
 116 }
 117
 118 /**
 119  * aa_audit - Log a profile based audit event to the audit subsystem
 120  * @type: audit type for the message
 121  * @profile: profile to check against (NOT NULL)
 122  * @sa: audit event (NOT NULL)
 123  * @cb: optional callback fn for type specific fields (MAYBE NULL)
 124  *
 125  * Handle default message switching based off of audit mode flags
 126  *
 127  * Returns: error on failure
 128  */
 129 int aa_audit(int type, struct aa_profile *profile, struct common_audit_data *sa,
 130              void (*cb) (struct audit_buffer *, void *))
 131 {
 132         AA_BUG(!profile);
 133
 134         if (type == AUDIT_APPARMOR_AUTO) {
 135                 if (likely(!aad(sa)->error)) {
 136                         if (AUDIT_MODE(profile) != AUDIT_ALL)
 137                                 return 0;
 138                         type = AUDIT_APPARMOR_AUDIT;
 139                 } else if (COMPLAIN_MODE(profile))
 140                         type = AUDIT_APPARMOR_ALLOWED;
 141                 else
 142                         type = AUDIT_APPARMOR_DENIED;
 143         }
 144         if (AUDIT_MODE(profile) == AUDIT_QUIET ||
 145             (type == AUDIT_APPARMOR_DENIED &&
 146              AUDIT_MODE(profile) == AUDIT_QUIET))
 147                 return aad(sa)->error;
 148
 149         if (KILL_MODE(profile) && type == AUDIT_APPARMOR_DENIED)
 150                 type = AUDIT_APPARMOR_KILL;
 151
 152         aad(sa)->label = &profile->label;
 153
 154         aa_audit_msg(type, sa, cb);
 155
 156         if (aad(sa)->type == AUDIT_APPARMOR_KILL)
 157                 (void)send_sig_info(SIGKILL, NULL,
 158                         sa->type == LSM_AUDIT_DATA_TASK && sa->u.tsk ?
 159                                     sa->u.tsk : current);
 160
 161         if (aad(sa)->type == AUDIT_APPARMOR_ALLOWED)
 162                 return complain_error(aad(sa)->error);
 163
 164         return aad(sa)->error;
 165 }
 166
 167 struct aa_audit_rule {
 168         struct aa_label *label;
 169 };
 170
 171 void aa_audit_rule_free(void *vrule)
 172 {
 173         struct aa_audit_rule *rule = vrule;
 174
 175         if (rule) {
 176                 if (!IS_ERR(rule->label))
 177                         aa_put_label(rule->label);
 178                 kfree(rule);
 179         }
 180 }
 181
 182 int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 183 {
 184         struct aa_audit_rule *rule;
 185
 186         switch (field) {
 187         case AUDIT_SUBJ_ROLE:
 188                 if (op != Audit_equal && op != Audit_not_equal)
 189                         return -EINVAL;
 190                 break;
 191         default:
 192                 return -EINVAL;
 193         }
 194
 195         rule = kzalloc(sizeof(struct aa_audit_rule), GFP_KERNEL);
 196
 197         if (!rule)
 198                 return -ENOMEM;
 199
 200         /* Currently rules are treated as coming from the root ns */
 201         rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
 202                                      GFP_KERNEL, true, false);
 203         if (IS_ERR(rule->label)) {
 204                 aa_audit_rule_free(rule);
 205                 return PTR_ERR(rule->label);
 206         }
 207
 208         *vrule = rule;
 209         return 0;
 210 }
 211
 212 int aa_audit_rule_known(struct audit_krule *rule)
 213 {
 214         int i;
 215
 216         for (i = 0; i < rule->field_count; i++) {
 217                 struct audit_field *f = &rule->fields[i];
 218
 219                 switch (f->type) {
 220                 case AUDIT_SUBJ_ROLE:
 221                         return 1;
 222                 }
 223         }
 224
 225         return 0;
 226 }
 227
 228 int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
 229                         struct audit_context *actx)
 230 {
 231         struct aa_audit_rule *rule = vrule;
 232         struct aa_label *label;
 233         int found = 0;
 234
 235         label = aa_secid_to_label(sid);
 236
 237         if (!label)
 238                 return -ENOENT;
 239
 240         if (aa_label_is_subset(label, rule->label))
 241                 found = 1;
 242
 243         switch (field) {
 244         case AUDIT_SUBJ_ROLE:
 245                 switch (op) {
 246                 case Audit_equal:
 247                         return found;
 248                 case Audit_not_equal:
 249                         return !found;
 250                 }
 251         }
 252         return 0;
 253 }