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2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

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