security/apparmor/audit.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AppArmor security module
   4  *
   5  * This file contains AppArmor auditing functions
   6  *
   7  * Copyright (C) 1998-2008 Novell/SUSE
   8  * Copyright 2009-2010 Canonical Ltd.
   9  */
  10
  11 #include <linux/audit.h>
  12 #include <linux/socket.h>
  13
  14 #include "include/apparmor.h"
  15 #include "include/audit.h"
  16 #include "include/policy.h"
  17 #include "include/policy_ns.h"
  18 #include "include/secid.h"
  19
  20 const char *const audit_mode_names[] = {
  21         "normal",
  22         "quiet_denied",
  23         "quiet",
  24         "noquiet",
  25         "all"
  26 };
  27
  28 static const char *const aa_audit_type[] = {
  29         "AUDIT",
  30         "ALLOWED",
  31         "DENIED",
  32         "HINT",
  33         "STATUS",
  34         "ERROR",
  35         "KILLED",
  36         "AUTO"
  37 };
  38
  39 static const char *const aa_class_names[] = {
  40         "none",
  41         "unknown",
  42         "file",
  43         "cap",
  44         "net",
  45         "rlimits",
  46         "domain",
  47         "mount",
  48         "unknown",
  49         "ptrace",
  50         "signal",
  51         "xmatch",
  52         "unknown",
  53         "unknown",
  54         "net",
  55         "unknown",
  56         "label",
  57         "posix_mqueue",
  58         "io_uring",
  59         "module",
  60         "lsm",
  61         "namespace",
  62         "io_uring",
  63         "unknown",
  64         "unknown",
  65         "unknown",
  66         "unknown",
  67         "unknown",
  68         "unknown",
  69         "unknown",
  70         "unknown",
  71         "X",
  72         "dbus",
  73 };
  74
  75
  76 /*
  77  * Currently AppArmor auditing is fed straight into the audit framework.
  78  *
  79  * TODO:
  80  * netlink interface for complain mode
  81  * user auditing, - send user auditing to netlink interface
  82  * system control of whether user audit messages go to system log
  83  */
  84
  85 /**
  86  * audit_pre() - core AppArmor function.
  87  * @ab: audit buffer to fill (NOT NULL)
  88  * @va: audit structure containing data to audit (NOT NULL)
  89  *
  90  * Record common AppArmor audit data from @va
  91  */
  92 static void audit_pre(struct audit_buffer *ab, void *va)
  93 {
  94         struct apparmor_audit_data *ad = aad_of_va(va);
  95
  96         if (aa_g_audit_header) {
  97                 audit_log_format(ab, "apparmor=\"%s\"",
  98                                  aa_audit_type[ad->type]);
  99         }
 100
 101         if (ad->op)
 102                 audit_log_format(ab, " operation=\"%s\"", ad->op);
 103
 104         if (ad->class)
 105                 audit_log_format(ab, " class=\"%s\"",
 106                                  ad->class <= AA_CLASS_LAST ?
 107                                  aa_class_names[ad->class] :
 108                                  "unknown");
 109
 110         if (ad->info) {
 111                 audit_log_format(ab, " info=\"%s\"", ad->info);
 112                 if (ad->error)
 113                         audit_log_format(ab, " error=%d", ad->error);
 114         }
 115
 116         if (ad->subj_label) {
 117                 struct aa_label *label = ad->subj_label;
 118
 119                 if (label_isprofile(label)) {
 120                         struct aa_profile *profile = labels_profile(label);
 121
 122                         if (profile->ns != root_ns) {
 123                                 audit_log_format(ab, " namespace=");
 124                                 audit_log_untrustedstring(ab,
 125                                                        profile->ns->base.hname);
 126                         }
 127                         audit_log_format(ab, " profile=");
 128                         audit_log_untrustedstring(ab, profile->base.hname);
 129                 } else {
 130                         audit_log_format(ab, " label=");
 131                         aa_label_xaudit(ab, root_ns, label, FLAG_VIEW_SUBNS,
 132                                         GFP_ATOMIC);
 133                 }
 134         }
 135
 136         if (ad->name) {
 137                 audit_log_format(ab, " name=");
 138                 audit_log_untrustedstring(ab, ad->name);
 139         }
 140 }
 141
 142 /**
 143  * aa_audit_msg - Log a message to the audit subsystem
 144  * @type: audit type for the message
 145  * @ad: audit event structure (NOT NULL)
 146  * @cb: optional callback fn for type specific fields (MAYBE NULL)
 147  */
 148 void aa_audit_msg(int type, struct apparmor_audit_data *ad,
 149                   void (*cb) (struct audit_buffer *, void *))
 150 {
 151         ad->type = type;
 152         common_lsm_audit(&ad->common, audit_pre, cb);
 153 }
 154
 155 /**
 156  * aa_audit - Log a profile based audit event to the audit subsystem
 157  * @type: audit type for the message
 158  * @profile: profile to check against (NOT NULL)
 159  * @ad: audit event (NOT NULL)
 160  * @cb: optional callback fn for type specific fields (MAYBE NULL)
 161  *
 162  * Handle default message switching based off of audit mode flags
 163  *
 164  * Returns: error on failure
 165  */
 166 int aa_audit(int type, struct aa_profile *profile,
 167              struct apparmor_audit_data *ad,
 168              void (*cb) (struct audit_buffer *, void *))
 169 {
 170         AA_BUG(!profile);
 171
 172         if (type == AUDIT_APPARMOR_AUTO) {
 173                 if (likely(!ad->error)) {
 174                         if (AUDIT_MODE(profile) != AUDIT_ALL)
 175                                 return 0;
 176                         type = AUDIT_APPARMOR_AUDIT;
 177                 } else if (COMPLAIN_MODE(profile))
 178                         type = AUDIT_APPARMOR_ALLOWED;
 179                 else
 180                         type = AUDIT_APPARMOR_DENIED;
 181         }
 182         if (AUDIT_MODE(profile) == AUDIT_QUIET ||
 183             (type == AUDIT_APPARMOR_DENIED &&
 184              AUDIT_MODE(profile) == AUDIT_QUIET_DENIED))
 185                 return ad->error;
 186
 187         if (KILL_MODE(profile) && type == AUDIT_APPARMOR_DENIED)
 188                 type = AUDIT_APPARMOR_KILL;
 189
 190         ad->subj_label = &profile->label;
 191
 192         aa_audit_msg(type, ad, cb);
 193
 194         if (ad->type == AUDIT_APPARMOR_KILL)
 195                 (void)send_sig_info(SIGKILL, NULL,
 196                         ad->common.type == LSM_AUDIT_DATA_TASK &&
 197                         ad->common.u.tsk ? ad->common.u.tsk : current);
 198
 199         if (ad->type == AUDIT_APPARMOR_ALLOWED)
 200                 return complain_error(ad->error);
 201
 202         return ad->error;
 203 }
 204
 205 struct aa_audit_rule {
 206         struct aa_label *label;
 207 };
 208
 209 void aa_audit_rule_free(void *vrule)
 210 {
 211         struct aa_audit_rule *rule = vrule;
 212
 213         if (rule) {
 214                 if (!IS_ERR(rule->label))
 215                         aa_put_label(rule->label);
 216                 kfree(rule);
 217         }
 218 }
 219
 220 int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, gfp_t gfp)
 221 {
 222         struct aa_audit_rule *rule;
 223
 224         switch (field) {
 225         case AUDIT_SUBJ_ROLE:
 226                 if (op != Audit_equal && op != Audit_not_equal)
 227                         return -EINVAL;
 228                 break;
 229         default:
 230                 return -EINVAL;
 231         }
 232
 233         rule = kzalloc(sizeof(struct aa_audit_rule), gfp);
 234
 235         if (!rule)
 236                 return -ENOMEM;
 237
 238         /* Currently rules are treated as coming from the root ns */
 239         rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
 240                                      gfp, true, false);
 241         if (IS_ERR(rule->label)) {
 242                 int err = PTR_ERR(rule->label);
 243                 aa_audit_rule_free(rule);
 244                 return err;
 245         }
 246
 247         *vrule = rule;
 248         return 0;
 249 }
 250
 251 int aa_audit_rule_known(struct audit_krule *rule)
 252 {
 253         int i;
 254
 255         for (i = 0; i < rule->field_count; i++) {
 256                 struct audit_field *f = &rule->fields[i];
 257
 258                 switch (f->type) {
 259                 case AUDIT_SUBJ_ROLE:
 260                         return 1;
 261                 }
 262         }
 263
 264         return 0;
 265 }
 266
 267 int aa_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule)
 268 {
 269         struct aa_audit_rule *rule = vrule;
 270         struct aa_label *label;
 271         int found = 0;
 272
 273         label = prop->apparmor.label;
 274
 275         if (!label)
 276                 return -ENOENT;
 277
 278         if (aa_label_is_subset(label, rule->label))
 279                 found = 1;
 280
 281         switch (field) {
 282         case AUDIT_SUBJ_ROLE:
 283                 switch (op) {
 284                 case Audit_equal:
 285                         return found;
 286                 case Audit_not_equal:
 287                         return !found;
 288                 }
 289         }
 290         return 0;
 291 }