1069 lines
27 KiB
C
1069 lines
27 KiB
C
/*
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* Implementation of the kernel access vector cache (AVC).
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*
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* Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
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* James Morris <jmorris@redhat.com>
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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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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/dcache.h>
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <net/sock.h>
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#include <linux/un.h>
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#include <net/af_unix.h>
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#include <linux/ip.h>
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#include <linux/audit.h>
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#include <linux/ipv6.h>
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#include <net/ipv6.h>
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#include "avc.h"
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#include "avc_ss.h"
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#ifdef CONFIG_AUDIT
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#include "class_to_string.h"
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#endif
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#include "common_perm_to_string.h"
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#include "av_inherit.h"
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#include "av_perm_to_string.h"
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#include "objsec.h"
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#define AVC_CACHE_SLOTS 512
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#define AVC_CACHE_MAXNODES 410
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struct avc_entry {
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u32 ssid;
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u32 tsid;
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u16 tclass;
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struct av_decision avd;
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int used; /* used recently */
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};
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struct avc_node {
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struct avc_entry ae;
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struct avc_node *next;
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};
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struct avc_cache {
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struct avc_node *slots[AVC_CACHE_SLOTS];
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u32 lru_hint; /* LRU hint for reclaim scan */
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u32 active_nodes;
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u32 latest_notif; /* latest revocation notification */
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};
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struct avc_callback_node {
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int (*callback) (u32 event, u32 ssid, u32 tsid,
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u16 tclass, u32 perms,
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u32 *out_retained);
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u32 events;
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u32 ssid;
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u32 tsid;
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u16 tclass;
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u32 perms;
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struct avc_callback_node *next;
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};
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static spinlock_t avc_lock = SPIN_LOCK_UNLOCKED;
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static struct avc_node *avc_node_freelist;
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static struct avc_cache avc_cache;
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static unsigned avc_cache_stats[AVC_NSTATS];
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static struct avc_callback_node *avc_callbacks;
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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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#ifdef AVC_CACHE_STATS
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static inline void avc_cache_stats_incr(int type)
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{
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avc_cache_stats[type]++;
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}
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static inline void avc_cache_stats_add(int type, unsigned val)
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{
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avc_cache_stats[type] += val;
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}
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#else
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static inline void avc_cache_stats_incr(int type)
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{ }
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static inline void avc_cache_stats_add(int type, unsigned val)
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{ }
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#endif
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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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void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
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{
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char **common_pts = NULL;
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u32 common_base = 0;
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int i, i2, perm;
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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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for (i = 0; i < ARRAY_SIZE(av_inherit); i++) {
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if (av_inherit[i].tclass == tclass) {
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common_pts = av_inherit[i].common_pts;
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common_base = av_inherit[i].common_base;
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break;
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}
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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 (perm < common_base) {
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if (perm & av)
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audit_log_format(ab, " %s", common_pts[i]);
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i++;
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perm <<= 1;
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}
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while (i < sizeof(av) * 8) {
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if (perm & av) {
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for (i2 = 0; i2 < ARRAY_SIZE(av_perm_to_string); i2++) {
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if ((av_perm_to_string[i2].tclass == tclass) &&
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(av_perm_to_string[i2].value == perm))
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break;
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}
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if (i2 < ARRAY_SIZE(av_perm_to_string))
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audit_log_format(ab, " %s",
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av_perm_to_string[i2].name);
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}
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i++;
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perm <<= 1;
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}
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audit_log_format(ab, " }");
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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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void avc_dump_query(struct audit_buffer *ab, 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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rc = security_sid_to_context(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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rc = security_sid_to_context(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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audit_log_format(ab, " tclass=%s", class_to_string[tclass]);
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}
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/**
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* avc_init - Initialize the AVC.
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*
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* Initialize the access vector cache.
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*/
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void __init avc_init(void)
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{
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struct avc_node *new;
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int i;
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for (i = 0; i < AVC_CACHE_MAXNODES; i++) {
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new = kmalloc(sizeof(*new), GFP_ATOMIC);
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if (!new) {
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printk(KERN_WARNING "avc: only able to allocate "
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"%d entries\n", i);
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break;
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}
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memset(new, 0, sizeof(*new));
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new->next = avc_node_freelist;
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avc_node_freelist = new;
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}
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audit_log(current->audit_context, "AVC INITIALIZED\n");
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}
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#if 0
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static void avc_hash_eval(char *tag)
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{
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int i, chain_len, max_chain_len, slots_used;
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struct avc_node *node;
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unsigned long flags;
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spin_lock_irqsave(&avc_lock,flags);
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slots_used = 0;
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max_chain_len = 0;
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for (i = 0; i < AVC_CACHE_SLOTS; i++) {
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node = avc_cache.slots[i];
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if (node) {
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slots_used++;
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chain_len = 0;
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while (node) {
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chain_len++;
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node = node->next;
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}
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if (chain_len > max_chain_len)
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max_chain_len = chain_len;
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}
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}
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spin_unlock_irqrestore(&avc_lock,flags);
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printk(KERN_INFO "\n");
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printk(KERN_INFO "%s avc: %d entries and %d/%d buckets used, longest "
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"chain length %d\n", tag, avc_cache.active_nodes, slots_used,
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AVC_CACHE_SLOTS, max_chain_len);
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}
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#else
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static inline void avc_hash_eval(char *tag)
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{ }
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#endif
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static inline struct avc_node *avc_reclaim_node(void)
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{
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struct avc_node *prev, *cur;
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int hvalue, try;
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hvalue = avc_cache.lru_hint;
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for (try = 0; try < 2; try++) {
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do {
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prev = NULL;
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cur = avc_cache.slots[hvalue];
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while (cur) {
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if (!cur->ae.used)
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goto found;
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cur->ae.used = 0;
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prev = cur;
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cur = cur->next;
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}
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hvalue = (hvalue + 1) & (AVC_CACHE_SLOTS - 1);
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} while (hvalue != avc_cache.lru_hint);
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}
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panic("avc_reclaim_node");
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found:
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avc_cache.lru_hint = hvalue;
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if (prev == NULL)
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avc_cache.slots[hvalue] = cur->next;
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else
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prev->next = cur->next;
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return cur;
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}
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static inline struct avc_node *avc_claim_node(u32 ssid,
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u32 tsid, u16 tclass)
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{
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struct avc_node *new;
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int hvalue;
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hvalue = avc_hash(ssid, tsid, tclass);
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if (avc_node_freelist) {
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new = avc_node_freelist;
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avc_node_freelist = avc_node_freelist->next;
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avc_cache.active_nodes++;
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} else {
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new = avc_reclaim_node();
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if (!new)
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goto out;
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}
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new->ae.used = 1;
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new->ae.ssid = ssid;
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new->ae.tsid = tsid;
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new->ae.tclass = tclass;
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new->next = avc_cache.slots[hvalue];
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avc_cache.slots[hvalue] = new;
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out:
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return new;
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}
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static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid,
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u16 tclass, int *probes)
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{
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struct avc_node *cur;
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int hvalue;
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int tprobes = 1;
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hvalue = avc_hash(ssid, tsid, tclass);
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cur = avc_cache.slots[hvalue];
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while (cur != NULL &&
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(ssid != cur->ae.ssid ||
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tclass != cur->ae.tclass ||
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tsid != cur->ae.tsid)) {
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tprobes++;
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cur = cur->next;
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}
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if (cur == NULL) {
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/* cache miss */
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goto out;
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}
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/* cache hit */
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if (probes)
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*probes = tprobes;
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cur->ae.used = 1;
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out:
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return cur;
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}
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/**
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* avc_lookup - Look up an AVC entry.
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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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* @requested: requested permissions, interpreted based on @tclass
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* @aeref: AVC entry reference
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*
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* Look up an AVC entry that is valid for the
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* @requested permissions between the SID pair
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* (@ssid, @tsid), interpreting the permissions
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* based on @tclass. If a valid AVC entry exists,
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* then this function updates @aeref to refer to the
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* entry and returns %0. Otherwise, this function
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* returns -%ENOENT.
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*/
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int avc_lookup(u32 ssid, u32 tsid, u16 tclass,
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u32 requested, struct avc_entry_ref *aeref)
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{
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struct avc_node *node;
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int probes, rc = 0;
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avc_cache_stats_incr(AVC_CAV_LOOKUPS);
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node = avc_search_node(ssid, tsid, tclass,&probes);
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if (node && ((node->ae.avd.decided & requested) == requested)) {
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avc_cache_stats_incr(AVC_CAV_HITS);
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avc_cache_stats_add(AVC_CAV_PROBES,probes);
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aeref->ae = &node->ae;
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goto out;
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}
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avc_cache_stats_incr(AVC_CAV_MISSES);
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rc = -ENOENT;
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out:
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return rc;
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}
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/**
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* avc_insert - Insert an AVC entry.
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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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* @ae: AVC entry
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* @aeref: AVC entry reference
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*
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* Insert an AVC entry for the SID pair
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* (@ssid, @tsid) and class @tclass.
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* The access vectors and the sequence number are
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* normally provided by the security server in
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* response to a security_compute_av() call. If the
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* sequence number @ae->avd.seqno is not less than the latest
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* revocation notification, then the function copies
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* the access vectors into a cache entry, updates
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* @aeref to refer to the entry, and returns %0.
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* Otherwise, this function returns -%EAGAIN.
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*/
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int avc_insert(u32 ssid, u32 tsid, u16 tclass,
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struct avc_entry *ae, struct avc_entry_ref *aeref)
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{
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struct avc_node *node;
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int rc = 0;
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if (ae->avd.seqno < avc_cache.latest_notif) {
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printk(KERN_WARNING "avc: seqno %d < latest_notif %d\n",
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ae->avd.seqno, avc_cache.latest_notif);
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rc = -EAGAIN;
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goto out;
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}
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node = avc_claim_node(ssid, tsid, tclass);
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if (!node) {
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rc = -ENOMEM;
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goto out;
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}
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node->ae.avd.allowed = ae->avd.allowed;
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node->ae.avd.decided = ae->avd.decided;
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node->ae.avd.auditallow = ae->avd.auditallow;
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node->ae.avd.auditdeny = ae->avd.auditdeny;
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node->ae.avd.seqno = ae->avd.seqno;
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aeref->ae = &node->ae;
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out:
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return rc;
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}
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|
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static inline void avc_print_ipv6_addr(struct audit_buffer *ab,
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struct in6_addr *addr, u16 port,
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char *name1, char *name2)
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{
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if (!ipv6_addr_any(addr))
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audit_log_format(ab, " %s=%04x:%04x:%04x:%04x:%04x:"
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"%04x:%04x:%04x", name1, NIP6(*addr));
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if (port)
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audit_log_format(ab, " %s=%d", name2, ntohs(port));
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}
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|
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static inline void avc_print_ipv4_addr(struct audit_buffer *ab, u32 addr,
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u16 port, char *name1, char *name2)
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{
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if (addr)
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audit_log_format(ab, " %s=%d.%d.%d.%d", name1, NIPQUAD(addr));
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if (port)
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audit_log_format(ab, " %s=%d", name2, ntohs(port));
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}
|
|
|
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/**
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* avc_audit - Audit the granting or denial of permissions.
|
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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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* @requested: requested permissions
|
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* @avd: access vector decisions
|
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* @result: result from avc_has_perm_noaudit
|
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* @a: auxiliary audit data
|
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*
|
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* Audit the granting or denial of permissions in accordance
|
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* with the policy. This function is typically called by
|
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* avc_has_perm() after a permission check, but can also be
|
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* called directly by callers who use avc_has_perm_noaudit()
|
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* in order to separate the permission check from the auditing.
|
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* For example, this separation is useful when the permission check must
|
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* be performed under a lock, to allow the lock to be released
|
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* before calling the auditing code.
|
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*/
|
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void avc_audit(u32 ssid, u32 tsid,
|
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u16 tclass, u32 requested,
|
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struct av_decision *avd, int result, struct avc_audit_data *a)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
struct inode *inode = NULL;
|
|
u32 denied, audited;
|
|
struct audit_buffer *ab;
|
|
|
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denied = requested & ~avd->allowed;
|
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if (denied) {
|
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audited = denied;
|
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if (!(audited & avd->auditdeny))
|
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return;
|
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} else if (result) {
|
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audited = denied = requested;
|
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} else {
|
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audited = requested;
|
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if (!(audited & avd->auditallow))
|
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return;
|
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}
|
|
|
|
ab = audit_log_start(current->audit_context);
|
|
if (!ab)
|
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return; /* audit_panic has been called */
|
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audit_log_format(ab, "avc: %s ", denied ? "denied" : "granted");
|
|
avc_dump_av(ab, tclass,audited);
|
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audit_log_format(ab, " for ");
|
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if (a && a->tsk)
|
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tsk = a->tsk;
|
|
if (tsk && tsk->pid) {
|
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struct mm_struct *mm;
|
|
struct vm_area_struct *vma;
|
|
audit_log_format(ab, " pid=%d", tsk->pid);
|
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if (tsk == current)
|
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mm = current->mm;
|
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else
|
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mm = get_task_mm(tsk);
|
|
if (mm) {
|
|
if (down_read_trylock(&mm->mmap_sem)) {
|
|
vma = mm->mmap;
|
|
while (vma) {
|
|
if ((vma->vm_flags & VM_EXECUTABLE) &&
|
|
vma->vm_file) {
|
|
audit_log_d_path(ab, "exe=",
|
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vma->vm_file->f_dentry,
|
|
vma->vm_file->f_vfsmnt);
|
|
break;
|
|
}
|
|
vma = vma->vm_next;
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
}
|
|
if (tsk != current)
|
|
mmput(mm);
|
|
} else {
|
|
audit_log_format(ab, " comm=%s", tsk->comm);
|
|
}
|
|
}
|
|
if (a) {
|
|
switch (a->type) {
|
|
case AVC_AUDIT_DATA_IPC:
|
|
audit_log_format(ab, " key=%d", a->u.ipc_id);
|
|
break;
|
|
case AVC_AUDIT_DATA_CAP:
|
|
audit_log_format(ab, " capability=%d", a->u.cap);
|
|
break;
|
|
case AVC_AUDIT_DATA_FS:
|
|
if (a->u.fs.dentry) {
|
|
struct dentry *dentry = a->u.fs.dentry;
|
|
if (a->u.fs.mnt) {
|
|
audit_log_d_path(ab, "path=", dentry,
|
|
a->u.fs.mnt);
|
|
} else {
|
|
audit_log_format(ab, " name=%s",
|
|
dentry->d_name.name);
|
|
}
|
|
inode = dentry->d_inode;
|
|
} else if (a->u.fs.inode) {
|
|
struct dentry *dentry;
|
|
inode = a->u.fs.inode;
|
|
dentry = d_find_alias(inode);
|
|
if (dentry) {
|
|
audit_log_format(ab, " name=%s",
|
|
dentry->d_name.name);
|
|
dput(dentry);
|
|
}
|
|
}
|
|
if (inode)
|
|
audit_log_format(ab, " dev=%s ino=%ld",
|
|
inode->i_sb->s_id,
|
|
inode->i_ino);
|
|
break;
|
|
case AVC_AUDIT_DATA_NET:
|
|
if (a->u.net.sk) {
|
|
struct sock *sk = a->u.net.sk;
|
|
struct unix_sock *u;
|
|
int len = 0;
|
|
char *p = NULL;
|
|
|
|
switch (sk->sk_family) {
|
|
case AF_INET: {
|
|
struct inet_opt *inet = inet_sk(sk);
|
|
|
|
avc_print_ipv4_addr(ab, inet->rcv_saddr,
|
|
inet->sport,
|
|
"laddr", "lport");
|
|
avc_print_ipv4_addr(ab, inet->daddr,
|
|
inet->dport,
|
|
"faddr", "fport");
|
|
break;
|
|
}
|
|
case AF_INET6: {
|
|
struct inet_opt *inet = inet_sk(sk);
|
|
struct ipv6_pinfo *inet6 = inet6_sk(sk);
|
|
|
|
avc_print_ipv6_addr(ab, &inet6->rcv_saddr,
|
|
inet->sport,
|
|
"laddr", "lport");
|
|
avc_print_ipv6_addr(ab, &inet6->daddr,
|
|
inet->dport,
|
|
"faddr", "fport");
|
|
break;
|
|
}
|
|
case AF_UNIX:
|
|
u = unix_sk(sk);
|
|
if (u->dentry) {
|
|
audit_log_d_path(ab, "path=",
|
|
u->dentry, u->mnt);
|
|
break;
|
|
}
|
|
if (!u->addr)
|
|
break;
|
|
len = u->addr->len-sizeof(short);
|
|
p = &u->addr->name->sun_path[0];
|
|
if (*p)
|
|
audit_log_format(ab,
|
|
"path=%*.*s", len,
|
|
len, p);
|
|
else
|
|
audit_log_format(ab,
|
|
"path=@%*.*s", len-1,
|
|
len-1, p+1);
|
|
break;
|
|
}
|
|
}
|
|
|
|
switch (a->u.net.family) {
|
|
case AF_INET:
|
|
avc_print_ipv4_addr(ab, a->u.net.v4info.saddr,
|
|
a->u.net.sport,
|
|
"saddr", "src");
|
|
avc_print_ipv4_addr(ab, a->u.net.v4info.daddr,
|
|
a->u.net.dport,
|
|
"daddr", "dest");
|
|
break;
|
|
case AF_INET6:
|
|
avc_print_ipv6_addr(ab, &a->u.net.v6info.saddr,
|
|
a->u.net.sport,
|
|
"saddr", "src");
|
|
avc_print_ipv6_addr(ab, &a->u.net.v6info.daddr,
|
|
a->u.net.dport,
|
|
"daddr", "dest");
|
|
break;
|
|
}
|
|
if (a->u.net.netif)
|
|
audit_log_format(ab, " netif=%s",
|
|
a->u.net.netif);
|
|
break;
|
|
}
|
|
}
|
|
audit_log_format(ab, " ");
|
|
avc_dump_query(ab, ssid, tsid, tclass);
|
|
audit_log_end(ab);
|
|
}
|
|
|
|
/**
|
|
* avc_add_callback - Register a callback for security events.
|
|
* @callback: callback function
|
|
* @events: security events
|
|
* @ssid: source security identifier or %SECSID_WILD
|
|
* @tsid: target security identifier or %SECSID_WILD
|
|
* @tclass: target security class
|
|
* @perms: permissions
|
|
*
|
|
* Register a callback function for events in the set @events
|
|
* related to the SID pair (@ssid, @tsid) and
|
|
* and the permissions @perms, interpreting
|
|
* @perms based on @tclass. Returns %0 on success or
|
|
* -%ENOMEM if insufficient memory exists to add the callback.
|
|
*/
|
|
int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
|
|
u16 tclass, u32 perms,
|
|
u32 *out_retained),
|
|
u32 events, u32 ssid, u32 tsid,
|
|
u16 tclass, u32 perms)
|
|
{
|
|
struct avc_callback_node *c;
|
|
int rc = 0;
|
|
|
|
c = kmalloc(sizeof(*c), GFP_ATOMIC);
|
|
if (!c) {
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
c->callback = callback;
|
|
c->events = events;
|
|
c->ssid = ssid;
|
|
c->tsid = tsid;
|
|
c->perms = perms;
|
|
c->next = avc_callbacks;
|
|
avc_callbacks = c;
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
static inline int avc_sidcmp(u32 x, u32 y)
|
|
{
|
|
return (x == y || x == SECSID_WILD || y == SECSID_WILD);
|
|
}
|
|
|
|
static inline void avc_update_node(u32 event, struct avc_node *node, u32 perms)
|
|
{
|
|
switch (event) {
|
|
case AVC_CALLBACK_GRANT:
|
|
node->ae.avd.allowed |= perms;
|
|
break;
|
|
case AVC_CALLBACK_TRY_REVOKE:
|
|
case AVC_CALLBACK_REVOKE:
|
|
node->ae.avd.allowed &= ~perms;
|
|
break;
|
|
case AVC_CALLBACK_AUDITALLOW_ENABLE:
|
|
node->ae.avd.auditallow |= perms;
|
|
break;
|
|
case AVC_CALLBACK_AUDITALLOW_DISABLE:
|
|
node->ae.avd.auditallow &= ~perms;
|
|
break;
|
|
case AVC_CALLBACK_AUDITDENY_ENABLE:
|
|
node->ae.avd.auditdeny |= perms;
|
|
break;
|
|
case AVC_CALLBACK_AUDITDENY_DISABLE:
|
|
node->ae.avd.auditdeny &= ~perms;
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int avc_update_cache(u32 event, u32 ssid, u32 tsid,
|
|
u16 tclass, u32 perms)
|
|
{
|
|
struct avc_node *node;
|
|
int i;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&avc_lock,flags);
|
|
|
|
if (ssid == SECSID_WILD || tsid == SECSID_WILD) {
|
|
/* apply to all matching nodes */
|
|
for (i = 0; i < AVC_CACHE_SLOTS; i++) {
|
|
for (node = avc_cache.slots[i]; node;
|
|
node = node->next) {
|
|
if (avc_sidcmp(ssid, node->ae.ssid) &&
|
|
avc_sidcmp(tsid, node->ae.tsid) &&
|
|
tclass == node->ae.tclass) {
|
|
avc_update_node(event,node,perms);
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
/* apply to one node */
|
|
node = avc_search_node(ssid, tsid, tclass, NULL);
|
|
if (node) {
|
|
avc_update_node(event,node,perms);
|
|
}
|
|
}
|
|
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int avc_control(u32 event, u32 ssid, u32 tsid,
|
|
u16 tclass, u32 perms,
|
|
u32 seqno, u32 *out_retained)
|
|
{
|
|
struct avc_callback_node *c;
|
|
u32 tretained = 0, cretained = 0;
|
|
int rc = 0;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* try_revoke only removes permissions from the cache
|
|
* state if they are not retained by the object manager.
|
|
* Hence, try_revoke must wait until after the callbacks have
|
|
* been invoked to update the cache state.
|
|
*/
|
|
if (event != AVC_CALLBACK_TRY_REVOKE)
|
|
avc_update_cache(event,ssid,tsid,tclass,perms);
|
|
|
|
for (c = avc_callbacks; c; c = c->next)
|
|
{
|
|
if ((c->events & event) &&
|
|
avc_sidcmp(c->ssid, ssid) &&
|
|
avc_sidcmp(c->tsid, tsid) &&
|
|
c->tclass == tclass &&
|
|
(c->perms & perms)) {
|
|
cretained = 0;
|
|
rc = c->callback(event, ssid, tsid, tclass,
|
|
(c->perms & perms),
|
|
&cretained);
|
|
if (rc)
|
|
goto out;
|
|
tretained |= cretained;
|
|
}
|
|
}
|
|
|
|
if (event == AVC_CALLBACK_TRY_REVOKE) {
|
|
/* revoke any unretained permissions */
|
|
perms &= ~tretained;
|
|
avc_update_cache(event,ssid,tsid,tclass,perms);
|
|
*out_retained = tretained;
|
|
}
|
|
|
|
spin_lock_irqsave(&avc_lock,flags);
|
|
if (seqno > avc_cache.latest_notif)
|
|
avc_cache.latest_notif = seqno;
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* avc_ss_grant - Grant previously denied permissions.
|
|
* @ssid: source security identifier or %SECSID_WILD
|
|
* @tsid: target security identifier or %SECSID_WILD
|
|
* @tclass: target security class
|
|
* @perms: permissions to grant
|
|
* @seqno: policy sequence number
|
|
*/
|
|
int avc_ss_grant(u32 ssid, u32 tsid, u16 tclass,
|
|
u32 perms, u32 seqno)
|
|
{
|
|
return avc_control(AVC_CALLBACK_GRANT,
|
|
ssid, tsid, tclass, perms, seqno, NULL);
|
|
}
|
|
|
|
/**
|
|
* avc_ss_try_revoke - Try to revoke previously granted permissions.
|
|
* @ssid: source security identifier or %SECSID_WILD
|
|
* @tsid: target security identifier or %SECSID_WILD
|
|
* @tclass: target security class
|
|
* @perms: permissions to grant
|
|
* @seqno: policy sequence number
|
|
* @out_retained: subset of @perms that are retained
|
|
*
|
|
* Try to revoke previously granted permissions, but
|
|
* only if they are not retained as migrated permissions.
|
|
* Return the subset of permissions that are retained via @out_retained.
|
|
*/
|
|
int avc_ss_try_revoke(u32 ssid, u32 tsid, u16 tclass,
|
|
u32 perms, u32 seqno, u32 *out_retained)
|
|
{
|
|
return avc_control(AVC_CALLBACK_TRY_REVOKE,
|
|
ssid, tsid, tclass, perms, seqno, out_retained);
|
|
}
|
|
|
|
/**
|
|
* avc_ss_revoke - Revoke previously granted permissions.
|
|
* @ssid: source security identifier or %SECSID_WILD
|
|
* @tsid: target security identifier or %SECSID_WILD
|
|
* @tclass: target security class
|
|
* @perms: permissions to grant
|
|
* @seqno: policy sequence number
|
|
*
|
|
* Revoke previously granted permissions, even if
|
|
* they are retained as migrated permissions.
|
|
*/
|
|
int avc_ss_revoke(u32 ssid, u32 tsid, u16 tclass,
|
|
u32 perms, u32 seqno)
|
|
{
|
|
return avc_control(AVC_CALLBACK_REVOKE,
|
|
ssid, tsid, tclass, perms, seqno, NULL);
|
|
}
|
|
|
|
/**
|
|
* avc_ss_reset - Flush the cache and revalidate migrated permissions.
|
|
* @seqno: policy sequence number
|
|
*/
|
|
int avc_ss_reset(u32 seqno)
|
|
{
|
|
struct avc_callback_node *c;
|
|
int i, rc = 0;
|
|
struct avc_node *node, *tmp;
|
|
unsigned long flags;
|
|
|
|
avc_hash_eval("reset");
|
|
|
|
spin_lock_irqsave(&avc_lock,flags);
|
|
|
|
for (i = 0; i < AVC_CACHE_SLOTS; i++) {
|
|
node = avc_cache.slots[i];
|
|
while (node) {
|
|
tmp = node;
|
|
node = node->next;
|
|
tmp->ae.ssid = tmp->ae.tsid = SECSID_NULL;
|
|
tmp->ae.tclass = SECCLASS_NULL;
|
|
tmp->ae.avd.allowed = tmp->ae.avd.decided = 0;
|
|
tmp->ae.avd.auditallow = tmp->ae.avd.auditdeny = 0;
|
|
tmp->ae.used = 0;
|
|
tmp->next = avc_node_freelist;
|
|
avc_node_freelist = tmp;
|
|
avc_cache.active_nodes--;
|
|
}
|
|
avc_cache.slots[i] = NULL;
|
|
}
|
|
avc_cache.lru_hint = 0;
|
|
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
|
|
for (i = 0; i < AVC_NSTATS; i++)
|
|
avc_cache_stats[i] = 0;
|
|
|
|
for (c = avc_callbacks; c; c = c->next) {
|
|
if (c->events & AVC_CALLBACK_RESET) {
|
|
rc = c->callback(AVC_CALLBACK_RESET,
|
|
0, 0, 0, 0, NULL);
|
|
if (rc)
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
spin_lock_irqsave(&avc_lock,flags);
|
|
if (seqno > avc_cache.latest_notif)
|
|
avc_cache.latest_notif = seqno;
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* avc_ss_set_auditallow - Enable or disable auditing of granted permissions.
|
|
* @ssid: source security identifier or %SECSID_WILD
|
|
* @tsid: target security identifier or %SECSID_WILD
|
|
* @tclass: target security class
|
|
* @perms: permissions to grant
|
|
* @seqno: policy sequence number
|
|
* @enable: enable flag.
|
|
*/
|
|
int avc_ss_set_auditallow(u32 ssid, u32 tsid, u16 tclass,
|
|
u32 perms, u32 seqno, u32 enable)
|
|
{
|
|
if (enable)
|
|
return avc_control(AVC_CALLBACK_AUDITALLOW_ENABLE,
|
|
ssid, tsid, tclass, perms, seqno, NULL);
|
|
else
|
|
return avc_control(AVC_CALLBACK_AUDITALLOW_DISABLE,
|
|
ssid, tsid, tclass, perms, seqno, NULL);
|
|
}
|
|
|
|
/**
|
|
* avc_ss_set_auditdeny - Enable or disable auditing of denied permissions.
|
|
* @ssid: source security identifier or %SECSID_WILD
|
|
* @tsid: target security identifier or %SECSID_WILD
|
|
* @tclass: target security class
|
|
* @perms: permissions to grant
|
|
* @seqno: policy sequence number
|
|
* @enable: enable flag.
|
|
*/
|
|
int avc_ss_set_auditdeny(u32 ssid, u32 tsid, u16 tclass,
|
|
u32 perms, u32 seqno, u32 enable)
|
|
{
|
|
if (enable)
|
|
return avc_control(AVC_CALLBACK_AUDITDENY_ENABLE,
|
|
ssid, tsid, tclass, perms, seqno, NULL);
|
|
else
|
|
return avc_control(AVC_CALLBACK_AUDITDENY_DISABLE,
|
|
ssid, tsid, tclass, perms, seqno, NULL);
|
|
}
|
|
|
|
/**
|
|
* avc_has_perm_noaudit - Check permissions but perform no auditing.
|
|
* @ssid: source security identifier
|
|
* @tsid: target security identifier
|
|
* @tclass: target security class
|
|
* @requested: requested permissions, interpreted based on @tclass
|
|
* @aeref: AVC entry reference
|
|
* @avd: access vector decisions
|
|
*
|
|
* Check the AVC to determine whether the @requested permissions are granted
|
|
* for the SID pair (@ssid, @tsid), interpreting the permissions
|
|
* based on @tclass, and call the security server on a cache miss to obtain
|
|
* a new decision and add it to the cache. Update @aeref to refer to an AVC
|
|
* entry with the resulting decisions, and return a copy of the decisions
|
|
* in @avd. Return %0 if all @requested permissions are granted,
|
|
* -%EACCES if any permissions are denied, or another -errno upon
|
|
* other errors. This function is typically called by avc_has_perm(),
|
|
* but may also be called directly to separate permission checking from
|
|
* auditing, e.g. in cases where a lock must be held for the check but
|
|
* should be released for the auditing.
|
|
*/
|
|
int avc_has_perm_noaudit(u32 ssid, u32 tsid,
|
|
u16 tclass, u32 requested,
|
|
struct avc_entry_ref *aeref, struct av_decision *avd)
|
|
{
|
|
struct avc_entry *ae;
|
|
int rc = 0;
|
|
unsigned long flags;
|
|
struct avc_entry entry;
|
|
u32 denied;
|
|
struct avc_entry_ref ref;
|
|
|
|
if (!aeref) {
|
|
avc_entry_ref_init(&ref);
|
|
aeref = &ref;
|
|
}
|
|
|
|
spin_lock_irqsave(&avc_lock, flags);
|
|
avc_cache_stats_incr(AVC_ENTRY_LOOKUPS);
|
|
ae = aeref->ae;
|
|
if (ae) {
|
|
if (ae->ssid == ssid &&
|
|
ae->tsid == tsid &&
|
|
ae->tclass == tclass &&
|
|
((ae->avd.decided & requested) == requested)) {
|
|
avc_cache_stats_incr(AVC_ENTRY_HITS);
|
|
ae->used = 1;
|
|
} else {
|
|
avc_cache_stats_incr(AVC_ENTRY_DISCARDS);
|
|
ae = NULL;
|
|
}
|
|
}
|
|
|
|
if (!ae) {
|
|
avc_cache_stats_incr(AVC_ENTRY_MISSES);
|
|
rc = avc_lookup(ssid, tsid, tclass, requested, aeref);
|
|
if (rc) {
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd);
|
|
if (rc)
|
|
goto out;
|
|
spin_lock_irqsave(&avc_lock, flags);
|
|
rc = avc_insert(ssid,tsid,tclass,&entry,aeref);
|
|
if (rc) {
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
goto out;
|
|
}
|
|
}
|
|
ae = aeref->ae;
|
|
}
|
|
|
|
if (avd)
|
|
memcpy(avd, &ae->avd, sizeof(*avd));
|
|
|
|
denied = requested & ~(ae->avd.allowed);
|
|
|
|
if (!requested || denied) {
|
|
if (selinux_enforcing) {
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
rc = -EACCES;
|
|
goto out;
|
|
} else {
|
|
ae->avd.allowed |= requested;
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
spin_unlock_irqrestore(&avc_lock,flags);
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* avc_has_perm - Check permissions and perform any appropriate auditing.
|
|
* @ssid: source security identifier
|
|
* @tsid: target security identifier
|
|
* @tclass: target security class
|
|
* @requested: requested permissions, interpreted based on @tclass
|
|
* @aeref: AVC entry reference
|
|
* @auditdata: auxiliary audit data
|
|
*
|
|
* Check the AVC to determine whether the @requested permissions are granted
|
|
* for the SID pair (@ssid, @tsid), interpreting the permissions
|
|
* based on @tclass, and call the security server on a cache miss to obtain
|
|
* a new decision and add it to the cache. Update @aeref to refer to an AVC
|
|
* entry with the resulting decisions. Audit the granting or denial of
|
|
* permissions in accordance with the policy. Return %0 if all @requested
|
|
* permissions are granted, -%EACCES if any permissions are denied, or
|
|
* another -errno upon other errors.
|
|
*/
|
|
int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
|
|
u32 requested, struct avc_entry_ref *aeref,
|
|
struct avc_audit_data *auditdata)
|
|
{
|
|
struct av_decision avd;
|
|
int rc;
|
|
|
|
rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, aeref, &avd);
|
|
avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
|
|
return rc;
|
|
}
|