5:50 p.m.
The following patch against audit.81 prevents duplicate syscall rules in a
given filter list by walking the list on each rule add.
I also removed the unused struct audit_entry in audit.c and made the static
inlines in auditsc.c consistent.
Signed-off-by: Amy Griffis <amy.griffis(a)hp.com>
audit.c | 5 ---
auditsc.c | 95 ++++++++++++++++++++++++++++++++++++--------------------------
2 files changed, 56 insertions(+), 44 deletions(-)
diff -Nrup linux-2.6.9.orig/kernel/audit.c linux-2.6.9/kernel/audit.c
--- linux-2.6.9.orig/kernel/audit.c 2005-07-29 13:37:34.581058000 -0400
+++ linux-2.6.9/kernel/audit.c 2005-07-29 13:41:32.018555559 -0400
@@ -147,11 +147,6 @@ static void audit_set_pid(struct audit_b
nlh->nlmsg_pid = pid;
}
-struct audit_entry {
- struct list_head list;
- struct audit_rule rule;
-};
-
static void audit_panic(const char *message)
{
switch (audit_failure)
diff -Nrup linux-2.6.9.orig/kernel/auditsc.c linux-2.6.9/kernel/auditsc.c
--- linux-2.6.9.orig/kernel/auditsc.c 2005-07-29 13:37:34.572269000 -0400
+++ linux-2.6.9/kernel/auditsc.c 2005-07-29 13:53:31.988273302 -0400
@@ -198,9 +198,36 @@ struct audit_entry {
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 int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
+static inline int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
{
int i;
@@ -229,18 +256,37 @@ static int audit_compare_rule(struct aud
/* 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 void audit_add_rule(struct audit_entry *entry,
+static inline int audit_add_rule(struct audit_rule *rule,
struct list_head *list)
{
+ struct audit_entry *entry;
+
+ /* 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 -EINVAL;
+ }
+ }
+
+ 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 void audit_free_rule(struct rcu_head *head)
+static inline void audit_free_rule(struct rcu_head *head)
{
struct audit_entry *e = container_of(head, struct audit_entry, rcu);
kfree(e);
@@ -267,32 +313,6 @@ static inline int audit_del_rule(struct
}
#ifdef CONFIG_NET
-/* Copy rule from user-space to kernel-space. Called during
- * AUDIT_ADD. */
-static 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;
-}
-
static int audit_list_rules(void *_dest)
{
int pid, seq;
@@ -322,7 +342,6 @@ static int audit_list_rules(void *_dest)
int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
uid_t loginuid)
{
- struct audit_entry *entry;
struct task_struct *tsk;
int *dest;
int err = 0;
@@ -349,16 +368,14 @@ int audit_receive_filter(int type, int p
}
break;
case AUDIT_ADD:
- if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL)))
- return -ENOMEM;
- if (audit_copy_rule(&entry->rule, data)) {
- kfree(entry);
+ listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND;
+ if (listnr >= AUDIT_NR_FILTERS)
return -EINVAL;
- }
- listnr = entry->rule.flags & ~AUDIT_FILTER_PREPEND;
- audit_add_rule(entry, &audit_filter_list[listnr]);
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "auid=%u added an audit rule\n", loginuid);
+
+ 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;