#include <linux/audit.h>
#include <linux/personality.h>
#include <linux/time.h>
-#include <linux/kthread.h>
#include <linux/netlink.h>
#include <linux/compiler.h>
#include <asm/unistd.h>
#include <linux/security.h>
+#include <linux/list.h>
-/* 0 = no checking
- 1 = put_count checking
- 2 = verbose put_count checking
-*/
-#define AUDIT_DEBUG 0
+#include "audit.h"
+
+extern struct list_head audit_filter_list[];
/* No syscall auditing will take place unless audit_enabled != 0. */
extern int audit_enabled;
* path_lookup. */
#define AUDIT_NAMES_RESERVED 7
-/* At task start time, the audit_state is set in the audit_context using
- a per-task filter. At syscall entry, the audit_state is augmented by
- the syscall filter. */
-enum audit_state {
- AUDIT_DISABLED, /* Do not create per-task audit_context.
- * No syscall-specific audit records can
- * be generated. */
- AUDIT_SETUP_CONTEXT, /* Create the per-task audit_context,
- * but don't necessarily fill it in at
- * syscall entry time (i.e., filter
- * instead). */
- AUDIT_BUILD_CONTEXT, /* Create the per-task audit_context,
- * and always fill it in at syscall
- * entry time. This makes a full
- * syscall record available if some
- * other part of the kernel decides it
- * should be recorded. */
- AUDIT_RECORD_CONTEXT /* Create the per-task audit_context,
- * always fill it in at syscall entry
- * time, and always write out the audit
- * record at syscall exit time. */
-};
-
/* When fs/namei.c:getname() is called, we store the pointer in name and
* we don't let putname() free it (instead we free all of the saved
* pointers at syscall exit time).
#endif
};
- /* Public API */
-/* There are three lists of rules -- one to search at task creation
- * time, one to search at syscall entry time, and another to search at
- * syscall exit time. */
-static struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
- LIST_HEAD_INIT(audit_filter_list[0]),
- LIST_HEAD_INIT(audit_filter_list[1]),
- LIST_HEAD_INIT(audit_filter_list[2]),
- LIST_HEAD_INIT(audit_filter_list[3]),
- LIST_HEAD_INIT(audit_filter_list[4]),
- LIST_HEAD_INIT(audit_filter_list[5]),
-#if AUDIT_NR_FILTERS != 6
-#error Fix audit_filter_list initialiser
-#endif
-};
-
-struct audit_entry {
- struct list_head list;
- struct rcu_head rcu;
- struct audit_rule rule;
-};
-
-extern int audit_pid;
-
-/* Copy rule from user-space to kernel-space. Called from
- * audit_add_rule during AUDIT_ADD. */
-static inline int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
-{
- int i;
-
- if (s->action != AUDIT_NEVER
- && s->action != AUDIT_POSSIBLE
- && s->action != AUDIT_ALWAYS)
- return -1;
- if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS)
- return -1;
- if ((s->flags & ~AUDIT_FILTER_PREPEND) >= AUDIT_NR_FILTERS)
- return -1;
-
- d->flags = s->flags;
- d->action = s->action;
- d->field_count = s->field_count;
- for (i = 0; i < d->field_count; i++) {
- d->fields[i] = s->fields[i];
- d->values[i] = s->values[i];
- }
- for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i];
- return 0;
-}
-
-/* Check to see if two rules are identical. It is called from
- * audit_add_rule during AUDIT_ADD and
- * audit_del_rule during AUDIT_DEL. */
-static inline int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
-{
- int i;
-
- if (a->flags != b->flags)
- return 1;
-
- if (a->action != b->action)
- return 1;
-
- if (a->field_count != b->field_count)
- return 1;
-
- for (i = 0; i < a->field_count; i++) {
- if (a->fields[i] != b->fields[i]
- || a->values[i] != b->values[i])
- return 1;
- }
-
- for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
- if (a->mask[i] != b->mask[i])
- return 1;
-
- return 0;
-}
-
-/* Note that audit_add_rule and audit_del_rule are called via
- * audit_receive() in audit.c, and are protected by
- * audit_netlink_sem. */
-static inline int audit_add_rule(struct audit_rule *rule,
- struct list_head *list)
-{
- struct audit_entry *entry;
- int i;
-
- /* Do not use the _rcu iterator here, since this is the only
- * addition routine. */
- list_for_each_entry(entry, list, list) {
- if (!audit_compare_rule(rule, &entry->rule)) {
- return -EEXIST;
- }
- }
-
- for (i = 0; i < rule->field_count; i++) {
- if (rule->fields[i] & AUDIT_UNUSED_BITS)
- return -EINVAL;
- if ( rule->fields[i] & AUDIT_NEGATE )
- rule->fields[i] |= AUDIT_NOT_EQUAL;
- else if ( (rule->fields[i] & AUDIT_OPERATORS) == 0 )
- rule->fields[i] |= AUDIT_EQUAL;
- rule->fields[i] &= (~AUDIT_NEGATE);
- }
-
- if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL)))
- return -ENOMEM;
- if (audit_copy_rule(&entry->rule, rule)) {
- kfree(entry);
- return -EINVAL;
- }
-
- if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
- entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
- list_add_rcu(&entry->list, list);
- } else {
- list_add_tail_rcu(&entry->list, list);
- }
-
- return 0;
-}
-
-static inline void audit_free_rule(struct rcu_head *head)
-{
- struct audit_entry *e = container_of(head, struct audit_entry, rcu);
- kfree(e);
-}
-
-/* Note that audit_add_rule and audit_del_rule are called via
- * audit_receive() in audit.c, and are protected by
- * audit_netlink_sem. */
-static inline int audit_del_rule(struct audit_rule *rule,
- struct list_head *list)
-{
- struct audit_entry *e;
-
- /* Do not use the _rcu iterator here, since this is the only
- * deletion routine. */
- list_for_each_entry(e, list, list) {
- if (!audit_compare_rule(rule, &e->rule)) {
- list_del_rcu(&e->list);
- call_rcu(&e->rcu, audit_free_rule);
- return 0;
- }
- }
- return -ENOENT; /* No matching rule */
-}
-
-static int audit_list_rules(void *_dest)
-{
- int pid, seq;
- int *dest = _dest;
- struct audit_entry *entry;
- int i;
-
- pid = dest[0];
- seq = dest[1];
- kfree(dest);
-
- down(&audit_netlink_sem);
-
- /* The *_rcu iterators not needed here because we are
- always called with audit_netlink_sem held. */
- for (i=0; i<AUDIT_NR_FILTERS; i++) {
- list_for_each_entry(entry, &audit_filter_list[i], list)
- audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
- &entry->rule, sizeof(entry->rule));
- }
- audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
-
- up(&audit_netlink_sem);
- return 0;
-}
-
-/**
- * audit_receive_filter - apply all rules to the specified message type
- * @type: audit message type
- * @pid: target pid for netlink audit messages
- * @uid: target uid for netlink audit messages
- * @seq: netlink audit message sequence (serial) number
- * @data: payload data
- * @loginuid: loginuid of sender
- */
-int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
- uid_t loginuid)
-{
- struct task_struct *tsk;
- int *dest;
- int err = 0;
- unsigned listnr;
-
- switch (type) {
- case AUDIT_LIST:
- /* We can't just spew out the rules here because we might fill
- * the available socket buffer space and deadlock waiting for
- * auditctl to read from it... which isn't ever going to
- * happen if we're actually running in the context of auditctl
- * trying to _send_ the stuff */
-
- dest = kmalloc(2 * sizeof(int), GFP_KERNEL);
- if (!dest)
- return -ENOMEM;
- dest[0] = pid;
- dest[1] = seq;
-
- tsk = kthread_run(audit_list_rules, dest, "audit_list_rules");
- if (IS_ERR(tsk)) {
- kfree(dest);
- err = PTR_ERR(tsk);
- }
- break;
- case AUDIT_ADD:
- listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND;
- if (listnr >= AUDIT_NR_FILTERS)
- return -EINVAL;
-
- err = audit_add_rule(data, &audit_filter_list[listnr]);
- if (!err)
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "auid=%u added an audit rule\n", loginuid);
- break;
- case AUDIT_DEL:
- listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND;
- if (listnr >= AUDIT_NR_FILTERS)
- return -EINVAL;
-
- err = audit_del_rule(data, &audit_filter_list[listnr]);
- if (!err)
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "auid=%u removed an audit rule\n", loginuid);
- break;
- default:
- return -EINVAL;
- }
-
- return err;
-}
-
-static int audit_comparator(const u32 left, const u32 op, const u32 right)
-{
- switch (op) {
- case AUDIT_EQUAL:
- return (left == right);
- case AUDIT_NOT_EQUAL:
- return (left != right);
- case AUDIT_LESS_THAN:
- return (left < right);
- case AUDIT_LESS_THAN_OR_EQUAL:
- return (left <= right);
- case AUDIT_GREATER_THAN:
- return (left > right);
- case AUDIT_GREATER_THAN_OR_EQUAL:
- return (left >= right);
- default:
- return -EINVAL;
- }
-}
/* Compare a task_struct with an audit_rule. Return 1 on match, 0
* otherwise. */
return AUDIT_BUILD_CONTEXT;
}
-static int audit_filter_user_rules(struct netlink_skb_parms *cb,
- struct audit_rule *rule,
- enum audit_state *state)
-{
- int i;
-
- for (i = 0; i < rule->field_count; i++) {
- u32 field = rule->fields[i] & ~AUDIT_OPERATORS;
- u32 op = rule->fields[i] & AUDIT_OPERATORS;
- u32 value = rule->values[i];
- int result = 0;
-
- switch (field) {
- case AUDIT_PID:
- result = audit_comparator(cb->creds.pid, op, value);
- break;
- case AUDIT_UID:
- result = audit_comparator(cb->creds.uid, op, value);
- break;
- case AUDIT_GID:
- result = audit_comparator(cb->creds.gid, op, value);
- break;
- case AUDIT_LOGINUID:
- result = audit_comparator(cb->loginuid, op, value);
- break;
- }
-
- if (!result)
- return 0;
- }
- switch (rule->action) {
- case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
- case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break;
- case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
- }
- return 1;
-}
-
-int audit_filter_user(struct netlink_skb_parms *cb, int type)
-{
- struct audit_entry *e;
- enum audit_state state;
- int ret = 1;
-
- rcu_read_lock();
- list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
- if (audit_filter_user_rules(cb, &e->rule, &state)) {
- if (state == AUDIT_DISABLED)
- ret = 0;
- break;
- }
- }
- rcu_read_unlock();
-
- return ret; /* Audit by default */
-}
-
-int audit_filter_type(int type)
-{
- struct audit_entry *e;
- int result = 0;
-
- rcu_read_lock();
- if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
- goto unlock_and_return;
-
- list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
- list) {
- struct audit_rule *rule = &e->rule;
- int i;
- for (i = 0; i < rule->field_count; i++) {
- u32 field = rule->fields[i] & ~AUDIT_OPERATORS;
- u32 op = rule->fields[i] & AUDIT_OPERATORS;
- u32 value = rule->values[i];
- if ( field == AUDIT_MSGTYPE ) {
- result = audit_comparator(type, op, value);
- if (!result)
- break;
- }
- }
- if (result)
- goto unlock_and_return;
- }
-unlock_and_return:
- rcu_read_unlock();
- return result;
-}
-
-
/* This should be called with task_lock() held. */
static inline struct audit_context *audit_get_context(struct task_struct *tsk,
int return_valid,
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