[PATCH 12/15] audit rules ordering, part 2

From: Al Viro
Date: Wed Dec 17 2008 - 00:15:23 EST



Fix the actual rule listing; add per-type lists _not_ used for matching,
with all exit,... sitting on one such list. Simplifies "do something
for all rules" logics, while we are at it...

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
include/linux/audit.h | 1 +
kernel/audit_tree.c | 1 +
kernel/auditfilter.c | 95 ++++++++++++++++++++-----------------------------
3 files changed, 41 insertions(+), 56 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index d28682c..4e37f06 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -371,6 +371,7 @@ struct audit_krule {
struct audit_watch *watch; /* associated watch */
struct audit_tree *tree; /* associated watched tree */
struct list_head rlist; /* entry in audit_{watch,tree}.rules list */
+ struct list_head list; /* for AUDIT_LIST* purposes only */
u64 prio;
};

diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 8b50944..48bddad 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -450,6 +450,7 @@ static void kill_rules(struct audit_tree *tree)
audit_log_end(ab);
rule->tree = NULL;
list_del_rcu(&entry->list);
+ list_del(&entry->rule.list);
call_rcu(&entry->rcu, audit_free_rule_rcu);
}
}
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 995a2e8..5d4edc6 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -86,6 +86,14 @@ struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
#error Fix audit_filter_list initialiser
#endif
};
+static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
+ LIST_HEAD_INIT(audit_rules_list[0]),
+ LIST_HEAD_INIT(audit_rules_list[1]),
+ LIST_HEAD_INIT(audit_rules_list[2]),
+ LIST_HEAD_INIT(audit_rules_list[3]),
+ LIST_HEAD_INIT(audit_rules_list[4]),
+ LIST_HEAD_INIT(audit_rules_list[5]),
+};

DEFINE_MUTEX(audit_filter_mutex);

@@ -1007,12 +1015,15 @@ static void audit_update_watch(struct audit_parent *parent,
list_del_rcu(&oentry->list);

nentry = audit_dupe_rule(&oentry->rule, nwatch);
- if (IS_ERR(nentry))
+ if (IS_ERR(nentry)) {
+ list_del(&oentry->rule.list);
audit_panic("error updating watch, removing");
- else {
+ } else {
int h = audit_hash_ino((u32)ino);
list_add(&nentry->rule.rlist, &nwatch->rules);
list_add_rcu(&nentry->list, &audit_inode_hash[h]);
+ list_replace(&oentry->rule.list,
+ &nentry->rule.list);
}

call_rcu(&oentry->rcu, audit_free_rule_rcu);
@@ -1077,6 +1088,7 @@ static void audit_remove_parent_watches(struct audit_parent *parent)
audit_log_end(ab);
}
list_del(&r->rlist);
+ list_del(&r->list);
list_del_rcu(&e->list);
call_rcu(&e->rcu, audit_free_rule_rcu);
}
@@ -1331,9 +1343,13 @@ static inline int audit_add_rule(struct audit_entry *entry,
}

if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
+ list_add(&entry->rule.list,
+ &audit_rules_list[entry->rule.listnr]);
list_add_rcu(&entry->list, list);
entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
} else {
+ list_add_tail(&entry->rule.list,
+ &audit_rules_list[entry->rule.listnr]);
list_add_tail_rcu(&entry->list, list);
}
#ifdef CONFIG_AUDITSYSCALL
@@ -1415,6 +1431,7 @@ static inline int audit_del_rule(struct audit_entry *entry,
audit_remove_tree_rule(&e->rule);

list_del_rcu(&e->list);
+ list_del(&e->rule.list);
call_rcu(&e->rcu, audit_free_rule_rcu);

#ifdef CONFIG_AUDITSYSCALL
@@ -1443,30 +1460,16 @@ out:
static void audit_list(int pid, int seq, struct sk_buff_head *q)
{
struct sk_buff *skb;
- struct audit_entry *entry;
+ struct audit_krule *r;
int i;

/* This is a blocking read, so use audit_filter_mutex instead of rcu
* iterator to sync with list writers. */
for (i=0; i<AUDIT_NR_FILTERS; i++) {
- list_for_each_entry(entry, &audit_filter_list[i], list) {
- struct audit_rule *rule;
-
- rule = audit_krule_to_rule(&entry->rule);
- if (unlikely(!rule))
- break;
- skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
- rule, sizeof(*rule));
- if (skb)
- skb_queue_tail(q, skb);
- kfree(rule);
- }
- }
- for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
- list_for_each_entry(entry, &audit_inode_hash[i], list) {
+ list_for_each_entry(r, &audit_rules_list[i], list) {
struct audit_rule *rule;

- rule = audit_krule_to_rule(&entry->rule);
+ rule = audit_krule_to_rule(r);
if (unlikely(!rule))
break;
skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
@@ -1485,30 +1488,16 @@ static void audit_list(int pid, int seq, struct sk_buff_head *q)
static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
{
struct sk_buff *skb;
- struct audit_entry *e;
+ struct audit_krule *r;
int i;

/* This is a blocking read, so use audit_filter_mutex instead of rcu
* iterator to sync with list writers. */
for (i=0; i<AUDIT_NR_FILTERS; i++) {
- list_for_each_entry(e, &audit_filter_list[i], list) {
- struct audit_rule_data *data;
-
- data = audit_krule_to_data(&e->rule);
- if (unlikely(!data))
- break;
- skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
- data, sizeof(*data) + data->buflen);
- if (skb)
- skb_queue_tail(q, skb);
- kfree(data);
- }
- }
- for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
- list_for_each_entry(e, &audit_inode_hash[i], list) {
+ list_for_each_entry(r, &audit_rules_list[i], list) {
struct audit_rule_data *data;

- data = audit_krule_to_data(&e->rule);
+ data = audit_krule_to_data(r);
if (unlikely(!data))
break;
skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
@@ -1789,35 +1778,37 @@ unlock_and_return:
return result;
}

-static int update_lsm_rule(struct audit_entry *entry)
+static int update_lsm_rule(struct audit_krule *r)
{
+ struct audit_entry *entry = container_of(r, struct audit_entry, rule);
struct audit_entry *nentry;
struct audit_watch *watch;
struct audit_tree *tree;
int err = 0;

- if (!security_audit_rule_known(&entry->rule))
+ if (!security_audit_rule_known(r))
return 0;

- watch = entry->rule.watch;
- tree = entry->rule.tree;
- nentry = audit_dupe_rule(&entry->rule, watch);
+ watch = r->watch;
+ tree = r->tree;
+ nentry = audit_dupe_rule(r, watch);
if (IS_ERR(nentry)) {
/* save the first error encountered for the
* return value */
err = PTR_ERR(nentry);
audit_panic("error updating LSM filters");
if (watch)
- list_del(&entry->rule.rlist);
+ list_del(&r->rlist);
list_del_rcu(&entry->list);
+ list_del(&r->list);
} else {
if (watch) {
list_add(&nentry->rule.rlist, &watch->rules);
- list_del(&entry->rule.rlist);
+ list_del(&r->rlist);
} else if (tree)
- list_replace_init(&entry->rule.rlist,
- &nentry->rule.rlist);
+ list_replace_init(&r->rlist, &nentry->rule.rlist);
list_replace_rcu(&entry->list, &nentry->list);
+ list_replace(&r->list, &nentry->rule.list);
}
call_rcu(&entry->rcu, audit_free_rule_rcu);

@@ -1831,27 +1822,19 @@ static int update_lsm_rule(struct audit_entry *entry)
* updated rule. */
int audit_update_lsm_rules(void)
{
- struct audit_entry *e, *n;
+ struct audit_krule *r, *n;
int i, err = 0;

/* audit_filter_mutex synchronizes the writers */
mutex_lock(&audit_filter_mutex);

for (i = 0; i < AUDIT_NR_FILTERS; i++) {
- list_for_each_entry_safe(e, n, &audit_filter_list[i], list) {
- int res = update_lsm_rule(e);
- if (!err)
- err = res;
- }
- }
- for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
- list_for_each_entry_safe(e, n, &audit_inode_hash[i], list) {
- int res = update_lsm_rule(e);
+ list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
+ int res = update_lsm_rule(r);
if (!err)
err = res;
}
}
-
mutex_unlock(&audit_filter_mutex);

return err;
--
1.5.6.5


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