Commit 62062cf8 authored by Eric Paris's avatar Eric Paris

audit: allow checking the type of audit message in the user filter

When userspace sends messages to the audit system it includes a type.
We want to be able to filter messages based on that type without have to
do the all or nothing option currently available on the
AUDIT_FILTER_TYPE filter list.  Instead we should be able to use the
AUDIT_FILTER_USER filter list and just use the message type as one part
of the matching decision.
Signed-off-by: 's avatarEric Paris <eparis@redhat.com>
parent 34c474de
......@@ -438,7 +438,7 @@ static inline void audit_log_secctx(struct audit_buffer *ab, u32 secid)
extern int audit_update_lsm_rules(void);
/* Private API (for audit.c only) */
extern int audit_filter_user(void);
extern int audit_filter_user(int type);
extern int audit_filter_type(int type);
extern int audit_receive_filter(int type, int pid, int seq,
void *data, size_t datasz, kuid_t loginuid,
......
......@@ -737,7 +737,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (!audit_enabled && msg_type != AUDIT_USER_AVC)
return 0;
err = audit_filter_user();
err = audit_filter_user(msg_type);
if (err == 1) {
err = 0;
if (msg_type == AUDIT_USER_TTY) {
......
......@@ -310,6 +310,18 @@ static u32 audit_to_op(u32 op)
return n;
}
/* check if a field is valid for a given list */
static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
{
switch(f->type) {
case AUDIT_MSGTYPE:
if (entry->rule.listnr != AUDIT_FILTER_TYPE &&
entry->rule.listnr != AUDIT_FILTER_USER)
return -EINVAL;
break;
};
return 0;
}
/* Translate struct audit_rule to kernel's rule respresentation.
* Exists for backward compatibility with userspace. */
......@@ -459,6 +471,13 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
f->gid = INVALID_GID;
f->lsm_str = NULL;
f->lsm_rule = NULL;
err = audit_field_valid(entry, f);
if (err)
goto exit_free;
err = -EINVAL;
switch(f->type) {
case AUDIT_UID:
case AUDIT_EUID:
......@@ -1354,7 +1373,7 @@ int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
return strncmp(p, dname, dlen);
}
static int audit_filter_user_rules(struct audit_krule *rule,
static int audit_filter_user_rules(struct audit_krule *rule, int type,
enum audit_state *state)
{
int i;
......@@ -1378,6 +1397,9 @@ static int audit_filter_user_rules(struct audit_krule *rule,
result = audit_uid_comparator(audit_get_loginuid(current),
f->op, f->uid);
break;
case AUDIT_MSGTYPE:
result = audit_comparator(type, f->op, f->val);
break;
case AUDIT_SUBJ_USER:
case AUDIT_SUBJ_ROLE:
case AUDIT_SUBJ_TYPE:
......@@ -1404,7 +1426,7 @@ static int audit_filter_user_rules(struct audit_krule *rule,
return 1;
}
int audit_filter_user(void)
int audit_filter_user(int type)
{
enum audit_state state = AUDIT_DISABLED;
struct audit_entry *e;
......@@ -1412,7 +1434,7 @@ int audit_filter_user(void)
rcu_read_lock();
list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
if (audit_filter_user_rules(&e->rule, &state)) {
if (audit_filter_user_rules(&e->rule, type, &state)) {
if (state == AUDIT_DISABLED)
ret = 0;
break;
......
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