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authorEric Paris <eparis@redhat.com>2013-04-16 13:08:43 -0400
committerEric Paris <eparis@redhat.com>2013-04-16 17:28:49 -0400
commit62062cf8a3a99a933efdac549da380f230dbe982 (patch)
tree8da676d774d02c3c8f0093e7f2586719072f522f
parent34c474de7b4bd451396d67647ac728b0433379a9 (diff)
downloadop-kernel-dev-62062cf8a3a99a933efdac549da380f230dbe982.zip
op-kernel-dev-62062cf8a3a99a933efdac549da380f230dbe982.tar.gz
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: Eric Paris <eparis@redhat.com>
-rw-r--r--include/linux/audit.h2
-rw-r--r--kernel/audit.c2
-rw-r--r--kernel/auditfilter.c28
3 files changed, 27 insertions, 5 deletions
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 8f92e1d..b26d7f1 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -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,
diff --git a/kernel/audit.c b/kernel/audit.c
index c45e6d2..1322714 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -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) {
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index f9fc54b..9e66600 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -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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