From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/security/selinux/avc.c | 190 +++++++++++++++++++++++++----------------------
1 files changed, 101 insertions(+), 89 deletions(-)
diff --git a/kernel/security/selinux/avc.c b/kernel/security/selinux/avc.c
index 717a4be..e1efe74 100644
--- a/kernel/security/selinux/avc.c
+++ b/kernel/security/selinux/avc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Implementation of the kernel access vector cache (AVC).
*
@@ -8,10 +9,6 @@
* Replaced the avc_lock spinlock by RCU.
*
* Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2,
- * as published by the Free Software Foundation.
*/
#include <linux/types.h>
#include <linux/stddef.h>
@@ -34,6 +31,9 @@
#include "avc_ss.h"
#include "classmap.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/avc.h>
+
#define AVC_CACHE_SLOTS 512
#define AVC_DEF_CACHE_THRESHOLD 512
#define AVC_CACHE_RECLAIM 16
@@ -43,6 +43,9 @@
#else
#define avc_cache_stats_incr(field) do {} while (0)
#endif
+
+#undef CREATE_TRACE_POINTS
+#include <trace/hooks/avc.h>
struct avc_entry {
u32 ssid;
@@ -127,75 +130,6 @@
static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
{
return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1);
-}
-
-/**
- * avc_dump_av - Display an access vector in human-readable form.
- * @tclass: target security class
- * @av: access vector
- */
-static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
-{
- const char **perms;
- int i, perm;
-
- if (av == 0) {
- audit_log_format(ab, " null");
- return;
- }
-
- BUG_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map));
- perms = secclass_map[tclass-1].perms;
-
- audit_log_format(ab, " {");
- i = 0;
- perm = 1;
- while (i < (sizeof(av) * 8)) {
- if ((perm & av) && perms[i]) {
- audit_log_format(ab, " %s", perms[i]);
- av &= ~perm;
- }
- i++;
- perm <<= 1;
- }
-
- if (av)
- audit_log_format(ab, " 0x%x", av);
-
- audit_log_format(ab, " }");
-}
-
-/**
- * avc_dump_query - Display a SID pair and a class in human-readable form.
- * @ssid: source security identifier
- * @tsid: target security identifier
- * @tclass: target security class
- */
-static void avc_dump_query(struct audit_buffer *ab, struct selinux_state *state,
- u32 ssid, u32 tsid, u16 tclass)
-{
- int rc;
- char *scontext;
- u32 scontext_len;
-
- rc = security_sid_to_context(state, ssid, &scontext, &scontext_len);
- if (rc)
- audit_log_format(ab, "ssid=%d", ssid);
- else {
- audit_log_format(ab, "scontext=%s", scontext);
- kfree(scontext);
- }
-
- rc = security_sid_to_context(state, tsid, &scontext, &scontext_len);
- if (rc)
- audit_log_format(ab, " tsid=%d", tsid);
- else {
- audit_log_format(ab, " tcontext=%s", scontext);
- kfree(scontext);
- }
-
- BUG_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map));
- audit_log_format(ab, " tclass=%s", secclass_map[tclass-1].name);
}
/**
@@ -510,6 +444,7 @@
static void avc_node_delete(struct selinux_avc *avc, struct avc_node *node)
{
+ trace_android_vh_selinux_avc_node_delete(node);
hlist_del_rcu(&node->list);
call_rcu(&node->rhead, avc_node_free);
atomic_dec(&avc->avc_cache.active_nodes);
@@ -526,6 +461,7 @@
static void avc_node_replace(struct selinux_avc *avc,
struct avc_node *new, struct avc_node *old)
{
+ trace_android_vh_selinux_avc_node_replace(old, new);
hlist_replace_rcu(&old->list, &new->list);
call_rcu(&old->rhead, avc_node_free);
atomic_dec(&avc->avc_cache.active_nodes);
@@ -634,8 +570,10 @@
avc_cache_stats_incr(lookups);
node = avc_search_node(avc, ssid, tsid, tclass);
- if (node)
+ if (node) {
+ trace_android_vh_selinux_avc_lookup(node, ssid, tsid, tclass);
return node;
+ }
avc_cache_stats_incr(misses);
return NULL;
@@ -719,6 +657,7 @@
}
}
hlist_add_head_rcu(&node->list, head);
+ trace_android_vh_selinux_avc_insert(node);
found:
spin_unlock_irqrestore(lock, flag);
return node;
@@ -733,11 +672,36 @@
static void avc_audit_pre_callback(struct audit_buffer *ab, void *a)
{
struct common_audit_data *ad = a;
- audit_log_format(ab, "avc: %s ",
- ad->selinux_audit_data->denied ? "denied" : "granted");
- avc_dump_av(ab, ad->selinux_audit_data->tclass,
- ad->selinux_audit_data->audited);
- audit_log_format(ab, " for ");
+ struct selinux_audit_data *sad = ad->selinux_audit_data;
+ u32 av = sad->audited;
+ const char **perms;
+ int i, perm;
+
+ audit_log_format(ab, "avc: %s ", sad->denied ? "denied" : "granted");
+
+ if (av == 0) {
+ audit_log_format(ab, " null");
+ return;
+ }
+
+ perms = secclass_map[sad->tclass-1].perms;
+
+ audit_log_format(ab, " {");
+ i = 0;
+ perm = 1;
+ while (i < (sizeof(av) * 8)) {
+ if ((perm & av) && perms[i]) {
+ audit_log_format(ab, " %s", perms[i]);
+ av &= ~perm;
+ }
+ i++;
+ perm <<= 1;
+ }
+
+ if (av)
+ audit_log_format(ab, " 0x%x", av);
+
+ audit_log_format(ab, " } for ");
}
/**
@@ -749,14 +713,57 @@
static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
{
struct common_audit_data *ad = a;
- audit_log_format(ab, " ");
- avc_dump_query(ab, ad->selinux_audit_data->state,
- ad->selinux_audit_data->ssid,
- ad->selinux_audit_data->tsid,
- ad->selinux_audit_data->tclass);
- if (ad->selinux_audit_data->denied) {
- audit_log_format(ab, " permissive=%u",
- ad->selinux_audit_data->result ? 0 : 1);
+ struct selinux_audit_data *sad = ad->selinux_audit_data;
+ char *scontext = NULL;
+ char *tcontext = NULL;
+ const char *tclass = NULL;
+ u32 scontext_len;
+ u32 tcontext_len;
+ int rc;
+
+ rc = security_sid_to_context(sad->state, sad->ssid, &scontext,
+ &scontext_len);
+ if (rc)
+ audit_log_format(ab, " ssid=%d", sad->ssid);
+ else
+ audit_log_format(ab, " scontext=%s", scontext);
+
+ rc = security_sid_to_context(sad->state, sad->tsid, &tcontext,
+ &tcontext_len);
+ if (rc)
+ audit_log_format(ab, " tsid=%d", sad->tsid);
+ else
+ audit_log_format(ab, " tcontext=%s", tcontext);
+
+ tclass = secclass_map[sad->tclass-1].name;
+ audit_log_format(ab, " tclass=%s", tclass);
+
+ if (sad->denied)
+ audit_log_format(ab, " permissive=%u", sad->result ? 0 : 1);
+
+ trace_selinux_audited(sad, scontext, tcontext, tclass);
+ kfree(tcontext);
+ kfree(scontext);
+
+ /* in case of invalid context report also the actual context string */
+ rc = security_sid_to_context_inval(sad->state, sad->ssid, &scontext,
+ &scontext_len);
+ if (!rc && scontext) {
+ if (scontext_len && scontext[scontext_len - 1] == '\0')
+ scontext_len--;
+ audit_log_format(ab, " srawcon=");
+ audit_log_n_untrustedstring(ab, scontext, scontext_len);
+ kfree(scontext);
+ }
+
+ rc = security_sid_to_context_inval(sad->state, sad->tsid, &scontext,
+ &scontext_len);
+ if (!rc && scontext) {
+ if (scontext_len && scontext[scontext_len - 1] == '\0')
+ scontext_len--;
+ audit_log_format(ab, " trawcon=");
+ audit_log_n_untrustedstring(ab, scontext, scontext_len);
+ kfree(scontext);
}
}
@@ -768,6 +775,9 @@
{
struct common_audit_data stack_data;
struct selinux_audit_data sad;
+
+ if (WARN_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map)))
+ return -EINVAL;
if (!a) {
a = &stack_data;
@@ -1052,7 +1062,8 @@
int rc = 0, rc2;
xp_node = &local_xp_node;
- BUG_ON(!requested);
+ if (WARN_ON(!requested))
+ return -EACCES;
rcu_read_lock();
@@ -1142,7 +1153,8 @@
int rc = 0;
u32 denied;
- BUG_ON(!requested);
+ if (WARN_ON(!requested))
+ return -EACCES;
rcu_read_lock();
--
Gitblit v1.6.2