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linux-next/security/apparmor/audit.c
Tyler Hicks 52e8c38001 apparmor: Fix memory leak of rule on error exit path
Currently on the error exit path the allocated rule is not free'd
causing a memory leak. Fix this by calling aa_audit_rule_free().

Detected by CoverityScan, CID#1468966 ("Resource leaks")

Fixes: cb740f574c7b ("apparmor: modify audit rule support to support profile stacks")
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-06-07 01:50:48 -07:00

254 lines
5.5 KiB
C

/*
* AppArmor security module
*
* This file contains AppArmor auditing functions
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*/
#include <linux/audit.h>
#include <linux/socket.h>
#include "include/apparmor.h"
#include "include/audit.h"
#include "include/policy.h"
#include "include/policy_ns.h"
#include "include/secid.h"
const char *const audit_mode_names[] = {
"normal",
"quiet_denied",
"quiet",
"noquiet",
"all"
};
static const char *const aa_audit_type[] = {
"AUDIT",
"ALLOWED",
"DENIED",
"HINT",
"STATUS",
"ERROR",
"KILLED",
"AUTO"
};
/*
* Currently AppArmor auditing is fed straight into the audit framework.
*
* TODO:
* netlink interface for complain mode
* user auditing, - send user auditing to netlink interface
* system control of whether user audit messages go to system log
*/
/**
* audit_base - core AppArmor function.
* @ab: audit buffer to fill (NOT NULL)
* @ca: audit structure containing data to audit (NOT NULL)
*
* Record common AppArmor audit data from @sa
*/
static void audit_pre(struct audit_buffer *ab, void *ca)
{
struct common_audit_data *sa = ca;
if (aa_g_audit_header) {
audit_log_format(ab, "apparmor=");
audit_log_string(ab, aa_audit_type[aad(sa)->type]);
}
if (aad(sa)->op) {
audit_log_format(ab, " operation=");
audit_log_string(ab, aad(sa)->op);
}
if (aad(sa)->info) {
audit_log_format(ab, " info=");
audit_log_string(ab, aad(sa)->info);
if (aad(sa)->error)
audit_log_format(ab, " error=%d", aad(sa)->error);
}
if (aad(sa)->label) {
struct aa_label *label = aad(sa)->label;
if (label_isprofile(label)) {
struct aa_profile *profile = labels_profile(label);
if (profile->ns != root_ns) {
audit_log_format(ab, " namespace=");
audit_log_untrustedstring(ab,
profile->ns->base.hname);
}
audit_log_format(ab, " profile=");
audit_log_untrustedstring(ab, profile->base.hname);
} else {
audit_log_format(ab, " label=");
aa_label_xaudit(ab, root_ns, label, FLAG_VIEW_SUBNS,
GFP_ATOMIC);
}
}
if (aad(sa)->name) {
audit_log_format(ab, " name=");
audit_log_untrustedstring(ab, aad(sa)->name);
}
}
/**
* aa_audit_msg - Log a message to the audit subsystem
* @sa: audit event structure (NOT NULL)
* @cb: optional callback fn for type specific fields (MAYBE NULL)
*/
void aa_audit_msg(int type, struct common_audit_data *sa,
void (*cb) (struct audit_buffer *, void *))
{
aad(sa)->type = type;
common_lsm_audit(sa, audit_pre, cb);
}
/**
* aa_audit - Log a profile based audit event to the audit subsystem
* @type: audit type for the message
* @profile: profile to check against (NOT NULL)
* @sa: audit event (NOT NULL)
* @cb: optional callback fn for type specific fields (MAYBE NULL)
*
* Handle default message switching based off of audit mode flags
*
* Returns: error on failure
*/
int aa_audit(int type, struct aa_profile *profile, struct common_audit_data *sa,
void (*cb) (struct audit_buffer *, void *))
{
AA_BUG(!profile);
if (type == AUDIT_APPARMOR_AUTO) {
if (likely(!aad(sa)->error)) {
if (AUDIT_MODE(profile) != AUDIT_ALL)
return 0;
type = AUDIT_APPARMOR_AUDIT;
} else if (COMPLAIN_MODE(profile))
type = AUDIT_APPARMOR_ALLOWED;
else
type = AUDIT_APPARMOR_DENIED;
}
if (AUDIT_MODE(profile) == AUDIT_QUIET ||
(type == AUDIT_APPARMOR_DENIED &&
AUDIT_MODE(profile) == AUDIT_QUIET))
return aad(sa)->error;
if (KILL_MODE(profile) && type == AUDIT_APPARMOR_DENIED)
type = AUDIT_APPARMOR_KILL;
aad(sa)->label = &profile->label;
aa_audit_msg(type, sa, cb);
if (aad(sa)->type == AUDIT_APPARMOR_KILL)
(void)send_sig_info(SIGKILL, NULL,
sa->type == LSM_AUDIT_DATA_TASK && sa->u.tsk ?
sa->u.tsk : current);
if (aad(sa)->type == AUDIT_APPARMOR_ALLOWED)
return complain_error(aad(sa)->error);
return aad(sa)->error;
}
struct aa_audit_rule {
struct aa_label *label;
};
void aa_audit_rule_free(void *vrule)
{
struct aa_audit_rule *rule = vrule;
if (rule) {
if (!IS_ERR(rule->label))
aa_put_label(rule->label);
kfree(rule);
}
}
int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
{
struct aa_audit_rule *rule;
switch (field) {
case AUDIT_SUBJ_ROLE:
if (op != Audit_equal && op != Audit_not_equal)
return -EINVAL;
break;
default:
return -EINVAL;
}
rule = kzalloc(sizeof(struct aa_audit_rule), GFP_KERNEL);
if (!rule)
return -ENOMEM;
/* Currently rules are treated as coming from the root ns */
rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
GFP_KERNEL, true, false);
if (IS_ERR(rule->label)) {
aa_audit_rule_free(rule);
return PTR_ERR(rule->label);
}
*vrule = rule;
return 0;
}
int aa_audit_rule_known(struct audit_krule *rule)
{
int i;
for (i = 0; i < rule->field_count; i++) {
struct audit_field *f = &rule->fields[i];
switch (f->type) {
case AUDIT_SUBJ_ROLE:
return 1;
}
}
return 0;
}
int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
struct audit_context *actx)
{
struct aa_audit_rule *rule = vrule;
struct aa_label *label;
int found = 0;
label = aa_secid_to_label(sid);
if (!label)
return -ENOENT;
if (aa_label_is_subset(label, rule->label))
found = 1;
switch (field) {
case AUDIT_SUBJ_ROLE:
switch (op) {
case Audit_equal:
return found;
case Audit_not_equal:
return !found;
}
}
return 0;
}