[PATCH 10/22] Audit: make audit_enabled per user namespace

From: Gao feng
Date: Tue Jun 18 2013 - 21:53:37 EST


This patch makes audit_enabled per user namespace,
Right now,use audit_enabled of init user namespace to
decide if audit is enabled no matter which user namespace
we belong to.

Signed-off-by: Gao feng <gaofeng@xxxxxxxxxxxxxx>
---
include/linux/audit.h | 4 +++-
include/linux/user_namespace.h | 1 +
kernel/audit.c | 32 ++++++++++++++++----------------
3 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 179351d..cc30db9 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -450,7 +450,8 @@ 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);
-extern int audit_enabled;
+#define audit_enabled (init_user_ns.audit.enabled)
+#define audit_enabled_ns(ns) (ns->audit.enabled)
#else /* CONFIG_AUDIT */
static inline __printf(4, 5)
void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
@@ -503,6 +504,7 @@ static inline void audit_set_user_ns(struct user_namespace *ns)
static inline void audit_free_user_ns(struct user_namespace *ns)
{ }
#define audit_enabled 0
+#define audit_enabled_ns(ns) 0
#endif /* CONFIG_AUDIT */
static inline void audit_log_string(struct audit_buffer *ab, const char *buf)
{
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 60dd6da..9972f0f 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -21,6 +21,7 @@ struct uid_gid_map { /* 64 bytes -- 1 cache line */
#ifdef CONFIG_AUDIT
struct audit_ctrl {
struct sock *sock;
+ int enabled;
int pid;
int portid;
struct sk_buff_head queue;
diff --git a/kernel/audit.c b/kernel/audit.c
index ca61cf0..758b1e8 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -78,11 +78,8 @@ static int audit_initialized;
#define AUDIT_OFF 0
#define AUDIT_ON 1
#define AUDIT_LOCKED 2
-int audit_enabled;
bool audit_ever_enabled;

-EXPORT_SYMBOL_GPL(audit_enabled);
-
/* Default state when kernel boots without any parameters. */
static int audit_default;

@@ -274,14 +271,15 @@ static int audit_log_config_change(char *function_name, int new, int old,
static int audit_do_config_change(char *function_name, int *to_change, int new)
{
int allow_changes, rc = 0, old = *to_change;
+ struct user_namespace *ns = current_user_ns();

/* check if we are locked */
- if (audit_enabled == AUDIT_LOCKED)
+ if (ns->audit.enabled == AUDIT_LOCKED)
allow_changes = 0;
else
allow_changes = 1;

- if (audit_enabled != AUDIT_OFF) {
+ if (ns->audit.enabled != AUDIT_OFF) {
rc = audit_log_config_change(function_name, new, old, allow_changes);
if (rc)
allow_changes = 0;
@@ -306,13 +304,14 @@ static int audit_set_backlog_limit(int limit)
return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
}

-static int audit_set_enabled(int state)
+static int audit_set_enabled(struct user_namespace *ns, int state)
{
int rc;
if (state < AUDIT_OFF || state > AUDIT_LOCKED)
return -EINVAL;

- rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
+ rc = audit_do_config_change("audit_enabled", &ns->audit.enabled,
+ state);
if (!rc)
audit_ever_enabled |= !!state;

@@ -625,7 +624,7 @@ static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
int rc = 0;
uid_t uid = from_kuid(&init_user_ns, current_uid());

- if (!audit_enabled) {
+ if (!audit_enabled_ns(&init_user_ns)) {
*ab = NULL;
return rc;
}
@@ -677,7 +676,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)

switch (msg_type) {
case AUDIT_GET:
- status_set.enabled = audit_enabled;
+ status_set.enabled = ns->audit.enabled;
status_set.failure = audit_failure;
status_set.pid = ns->audit.pid;
status_set.rate_limit = audit_rate_limit;
@@ -693,7 +692,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
return -EINVAL;
status_get = (struct audit_status *)data;
if (status_get->mask & AUDIT_STATUS_ENABLED) {
- err = audit_set_enabled(status_get->enabled);
+ err = audit_set_enabled(ns, status_get->enabled);
if (err < 0)
return err;
}
@@ -705,7 +704,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (status_get->mask & AUDIT_STATUS_PID) {
int new_pid = status_get->pid;

- if (audit_enabled != AUDIT_OFF)
+ if (ns->audit.enabled != AUDIT_OFF)
audit_log_config_change("audit_pid", new_pid,
ns->audit.pid, 1);
ns->audit.pid = new_pid;
@@ -722,7 +721,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
case AUDIT_USER:
case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
- if (!audit_enabled && msg_type != AUDIT_USER_AVC)
+ if (!audit_enabled_ns(ns) && msg_type != AUDIT_USER_AVC)
return 0;

err = audit_filter_user(msg_type);
@@ -755,9 +754,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
case AUDIT_DEL_RULE:
if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
return -EINVAL;
- if (audit_enabled == AUDIT_LOCKED) {
+ if (ns->audit.enabled == AUDIT_LOCKED) {
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
- audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
+ audit_log_format(ab, " audit_enabled=%d res=0",
+ ns->audit.enabled);
audit_log_end(ab);
return -EPERM;
}
@@ -965,7 +965,6 @@ static int __init audit_init(void)

audit_set_user_ns(&init_user_ns);
audit_initialized = AUDIT_INITIALIZED;
- audit_enabled = audit_default;
audit_ever_enabled |= !!audit_default;

audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
@@ -987,7 +986,7 @@ static int __init audit_enable(char *str)
printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");

if (audit_initialized == AUDIT_INITIALIZED) {
- audit_enabled = audit_default;
+ init_user_ns.audit.enabled = audit_default;
audit_ever_enabled |= !!audit_default;
} else if (audit_initialized == AUDIT_UNINITIALIZED) {
printk(" (after initialization)");
@@ -1792,6 +1791,7 @@ void audit_set_user_ns(struct user_namespace *ns)

skb_queue_head_init(&ns->audit.queue);
skb_queue_head_init(&ns->audit.hold_queue);
+ ns->audit.enabled = audit_default;
}

void audit_free_user_ns(struct user_namespace *ns)
--
1.8.1.4

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