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