*/
#include <linux/init.h>
-#include <asm/atomic.h>
#include <asm/types.h>
+#include <asm/atomic.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/audit.h>
#include <net/sock.h>
+#include <net/netlink.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
* contains the (non-zero) pid. */
int audit_pid;
-/* If audit_limit is non-zero, limit the rate of sending audit records
+/* If audit_rate_limit is non-zero, limit the rate of sending audit records
* to that number per second. This prevents DoS attacks, but results in
* audit records being dropped. */
static int audit_rate_limit;
/* Number of outstanding audit_buffers allowed. */
static int audit_backlog_limit = 64;
+static int audit_backlog_wait_time = 60 * HZ;
+static int audit_backlog_wait_overflow = 0;
/* The identity of the user shutting down the audit system. */
uid_t audit_sig_uid = -1;
* than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
* being placed on the freelist). */
static DEFINE_SPINLOCK(audit_freelist_lock);
-static int audit_freelist_count = 0;
+static int audit_freelist_count;
static LIST_HEAD(audit_freelist);
static struct sk_buff_head audit_skb_queue;
/* The netlink socket is only to be read by 1 CPU, which lets us assume
* that list additions and deletions never happen simultaneously in
* auditsc.c */
-DECLARE_MUTEX(audit_netlink_sem);
+DEFINE_MUTEX(audit_netlink_mutex);
/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
* audit records. Since printk uses a 1024 byte buffer, this buffer
struct list_head list;
struct sk_buff *skb; /* formatted skb ready to send */
struct audit_context *ctx; /* NULL or associated context */
- int gfp_mask;
+ gfp_t gfp_mask;
};
static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
nlh->nlmsg_pid = pid;
}
-struct audit_entry {
- struct list_head list;
- struct audit_rule rule;
-};
-
-static void audit_panic(const char *message)
+void audit_panic(const char *message)
{
switch (audit_failure)
{
return retval;
}
-/* Emit at least 1 message per second, even if audit_rate_check is
- * throttling. */
+/**
+ * audit_log_lost - conditionally log lost audit message event
+ * @message: the message stating reason for lost audit message
+ *
+ * Emit at least 1 message per second, even if audit_rate_check is
+ * throttling.
+ * Always increment the lost messages counter.
+*/
void audit_log_lost(const char *message)
{
static unsigned long last_msg = 0;
audit_backlog_limit);
audit_panic(message);
}
-
}
static int audit_set_rate_limit(int limit, uid_t loginuid)
return old;
}
-int kauditd_thread(void *dummy)
+static int kauditd_thread(void *dummy)
{
struct sk_buff *skb;
audit_pid = 0;
}
} else {
- printk(KERN_ERR "%s\n", skb->data + NLMSG_SPACE(0));
+ printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0));
kfree_skb(skb);
}
} else {
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&kauditd_wait, &wait);
- if (!skb_queue_len(&audit_skb_queue))
+ if (!skb_queue_len(&audit_skb_queue)) {
+ try_to_freeze();
schedule();
+ }
__set_current_state(TASK_RUNNING);
remove_wait_queue(&kauditd_wait, &wait);
}
}
+ return 0;
}
+/**
+ * audit_send_reply - send an audit reply message via netlink
+ * @pid: process id to send reply to
+ * @seq: sequence number
+ * @type: audit message type
+ * @done: done (last) flag
+ * @multi: multi-part message flag
+ * @payload: payload data
+ * @size: payload size
+ *
+ * Allocates an skb, builds the netlink message, and sends it to the pid.
+ * No failure notifications.
+ */
void audit_send_reply(int pid, int seq, int type, int done, int multi,
void *payload, int size)
{
switch (msg_type) {
case AUDIT_GET:
case AUDIT_LIST:
+ case AUDIT_LIST_RULES:
case AUDIT_SET:
case AUDIT_ADD:
+ case AUDIT_ADD_RULE:
case AUDIT_DEL:
+ case AUDIT_DEL_RULE:
case AUDIT_SIGNAL_INFO:
if (!cap_raised(eff_cap, CAP_AUDIT_CONTROL))
err = -EPERM;
break;
case AUDIT_USER:
case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
+ case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2:
if (!cap_raised(eff_cap, CAP_AUDIT_WRITE))
err = -EPERM;
break;
if (err)
return err;
- /* As soon as there's any sign of userspace auditd, start kauditd to talk to it */
+ /* As soon as there's any sign of userspace auditd,
+ * start kauditd to talk to it */
if (!kauditd_task)
kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
if (IS_ERR(kauditd_task)) {
break;
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)
return 0;
break;
case AUDIT_ADD:
case AUDIT_DEL:
- if (nlh->nlmsg_len < sizeof(struct audit_rule))
+ if (nlmsg_len(nlh) < sizeof(struct audit_rule))
return -EINVAL;
/* fallthrough */
case AUDIT_LIST:
err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
- uid, seq, data, loginuid);
+ uid, seq, data, nlmsg_len(nlh),
+ loginuid);
+ break;
+ case AUDIT_ADD_RULE:
+ case AUDIT_DEL_RULE:
+ if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
+ return -EINVAL;
+ /* fallthrough */
+ case AUDIT_LIST_RULES:
+ err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
+ uid, seq, data, nlmsg_len(nlh),
+ loginuid);
break;
case AUDIT_SIGNAL_INFO:
sig_data.uid = audit_sig_uid;
return err < 0 ? err : 0;
}
-/* Get message from skb (based on rtnetlink_rcv_skb). Each message is
+/*
+ * Get message from skb (based on rtnetlink_rcv_skb). Each message is
* processed by audit_receive_msg. Malformed skbs with wrong length are
- * discarded silently. */
+ * discarded silently.
+ */
static void audit_receive_skb(struct sk_buff *skb)
{
int err;
struct sk_buff *skb;
unsigned int qlen;
- down(&audit_netlink_sem);
+ mutex_lock(&audit_netlink_mutex);
for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
skb = skb_dequeue(&sk->sk_receive_queue);
audit_receive_skb(skb);
kfree_skb(skb);
}
- up(&audit_netlink_sem);
+ mutex_unlock(&audit_netlink_mutex);
}
{
printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
audit_default ? "enabled" : "disabled");
- audit_sock = netlink_kernel_create(NETLINK_AUDIT, audit_receive);
+ audit_sock = netlink_kernel_create(NETLINK_AUDIT, 0, audit_receive,
+ THIS_MODULE);
if (!audit_sock)
audit_panic("cannot initialize netlink socket");
+ else
+ audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
- audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
skb_queue_head_init(&audit_skb_queue);
audit_initialized = 1;
audit_enabled = audit_default;
audit_initialized ? "" : " (after initialization)");
if (audit_initialized)
audit_enabled = audit_default;
- return 0;
+ return 1;
}
__setup("audit=", audit_enable);
}
static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
- int gfp_mask, int type)
+ gfp_t gfp_mask, int type)
{
unsigned long flags;
struct audit_buffer *ab = NULL;
return NULL;
}
-/* Compute a serial number for the audit record. Audit records are
+/**
+ * audit_serial - compute a serial number for the audit record
+ *
+ * Compute a serial number for the audit record. Audit records are
* written to user-space as soon as they are generated, so a complete
* audit record may be written in several pieces. The timestamp of the
* record and this serial number are used by the user-space tools to
* (timestamp,serial) tuple is unique for each syscall and is live from
* syscall entry to syscall exit.
*
- * Atomic values are only guaranteed to be 24-bit, so we count down.
- *
* NOTE: Another possibility is to store the formatted records off the
* audit context (for those records that have a context), and emit them
* all at syscall exit. However, this could delay the reporting of
* significant errors until syscall exit (or never, if the system
- * halts). */
+ * halts).
+ */
unsigned int audit_serial(void)
{
- static atomic_t serial = ATOMIC_INIT(0xffffff);
- unsigned int a, b;
+ static spinlock_t serial_lock = SPIN_LOCK_UNLOCKED;
+ static unsigned int serial = 0;
+ unsigned long flags;
+ unsigned int ret;
+
+ spin_lock_irqsave(&serial_lock, flags);
do {
- a = atomic_read(&serial);
- if (atomic_dec_and_test(&serial))
- atomic_set(&serial, 0xffffff);
- b = atomic_read(&serial);
- } while (b != a - 1);
+ ret = ++serial;
+ } while (unlikely(!ret));
+ spin_unlock_irqrestore(&serial_lock, flags);
- return 0xffffff - b;
+ return ret;
}
static inline void audit_get_stamp(struct audit_context *ctx,
* will be written at syscall exit. If there is no associated task, tsk
* should be NULL. */
-struct audit_buffer *audit_log_start(struct audit_context *ctx, int gfp_mask,
+/**
+ * audit_log_start - obtain an audit buffer
+ * @ctx: audit_context (may be NULL)
+ * @gfp_mask: type of allocation
+ * @type: audit message type
+ *
+ * Returns audit_buffer pointer on success or NULL on error.
+ *
+ * Obtain an audit buffer. This routine does locking to obtain the
+ * audit buffer, but then no locking is required for calls to
+ * audit_log_*format. If the task (ctx) is a task that is currently in a
+ * syscall, then the syscall is marked as auditable and an audit record
+ * will be written at syscall exit. If there is no associated task, then
+ * task context (ctx) should be NULL.
+ */
+struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
int type)
{
struct audit_buffer *ab = NULL;
struct timespec t;
unsigned int serial;
int reserve;
+ unsigned long timeout_start = jiffies;
if (!audit_initialized)
return NULL;
+ if (unlikely(audit_filter_type(type)))
+ return NULL;
+
if (gfp_mask & __GFP_WAIT)
reserve = 0;
else
while (audit_backlog_limit
&& skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
- if (gfp_mask & __GFP_WAIT) {
- int ret = 1;
+ if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
+ && time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
+
/* Wait for auditd to drain the queue a little */
DECLARE_WAITQUEUE(wait, current);
set_current_state(TASK_INTERRUPTIBLE);
if (audit_backlog_limit &&
skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
- ret = schedule_timeout(HZ * 60);
+ schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
__set_current_state(TASK_RUNNING);
remove_wait_queue(&audit_backlog_wait, &wait);
- if (ret)
- continue;
+ continue;
}
if (audit_rate_check())
printk(KERN_WARNING
skb_queue_len(&audit_skb_queue),
audit_backlog_limit);
audit_log_lost("backlog limit exceeded");
+ audit_backlog_wait_time = audit_backlog_wait_overflow;
+ wake_up(&audit_backlog_wait);
return NULL;
}
/**
* audit_expand - expand skb in the audit buffer
* @ab: audit_buffer
+ * @extra: space to add at tail of the skb
*
* Returns 0 (no space) on failed expansion, or available space if
* successful.
return skb_tailroom(skb);
}
-/* Format an audit message into the audit buffer. If there isn't enough
+/*
+ * Format an audit message into the audit buffer. If there isn't enough
* room in the audit buffer, more room will be allocated and vsnprint
* will be called a second time. Currently, we assume that a printk
- * can't format message larger than 1024 bytes, so we don't either. */
+ * can't format message larger than 1024 bytes, so we don't either.
+ */
static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
va_list args)
{
/* The printk buffer is 1024 bytes long, so if we get
* here and AUDIT_BUFSIZ is at least 1024, then we can
* log everything that printk could have logged. */
- avail = audit_expand(ab, max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
+ avail = audit_expand(ab,
+ max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
if (!avail)
goto out;
len = vsnprintf(skb->tail, avail, fmt, args2);
return;
}
-/* Format a message into the audit buffer. All the work is done in
- * audit_log_vformat. */
+/**
+ * audit_log_format - format a message into the audit buffer.
+ * @ab: audit_buffer
+ * @fmt: format string
+ * @...: optional parameters matching @fmt string
+ *
+ * All the work is done in audit_log_vformat.
+ */
void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
{
va_list args;
va_end(args);
}
-/* This function will take the passed buf and convert it into a string of
- * ascii hex digits. The new string is placed onto the skb. */
-void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf,
+/**
+ * audit_log_hex - convert a buffer to hex and append it to the audit skb
+ * @ab: the audit_buffer
+ * @buf: buffer to convert to hex
+ * @len: length of @buf to be converted
+ *
+ * No return value; failure to expand is silently ignored.
+ *
+ * This function will take the passed buf and convert it into a string of
+ * ascii hex digits. The new string is placed onto the skb.
+ */
+void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf,
size_t len)
{
int i, avail, new_len;
skb_put(skb, len << 1); /* new string is twice the old string */
}
-/* This code will escape a string that is passed to it if the string
- * contains a control character, unprintable character, double quote mark,
+/**
+ * audit_log_unstrustedstring - log a string that may contain random characters
+ * @ab: audit_buffer
+ * @string: string to be logged
+ *
+ * This code will escape a string that is passed to it if the string
+ * contains a control character, unprintable character, double quote mark,
* or a space. Unescaped strings will start and end with a double quote mark.
- * Strings that are escaped are printed in hex (2 digits per char). */
+ * Strings that are escaped are printed in hex (2 digits per char).
+ */
void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
{
const unsigned char *p = string;
kfree(path);
}
-/* The netlink_* functions cannot be called inside an irq context, so
- * the audit buffer is places on a queue and a tasklet is scheduled to
+/**
+ * audit_log_end - end one audit record
+ * @ab: the audit_buffer
+ *
+ * The netlink_* functions cannot be called inside an irq context, so
+ * the audit buffer is placed on a queue and a tasklet is scheduled to
* remove them from the queue outside the irq context. May be called in
- * any context. */
+ * any context.
+ */
void audit_log_end(struct audit_buffer *ab)
{
if (!ab)
ab->skb = NULL;
wake_up_interruptible(&kauditd_wait);
} else {
- printk("%s\n", ab->skb->data + NLMSG_SPACE(0));
+ printk(KERN_NOTICE "%s\n", ab->skb->data + NLMSG_SPACE(0));
}
}
audit_buffer_free(ab);
}
-/* Log an audit record. This is a convenience function that calls
- * audit_log_start, audit_log_vformat, and audit_log_end. It may be
- * called in any context. */
-void audit_log(struct audit_context *ctx, int gfp_mask, int type,
+/**
+ * audit_log - Log an audit record
+ * @ctx: audit context
+ * @gfp_mask: type of allocation
+ * @type: audit message type
+ * @fmt: format string to use
+ * @...: variable parameters matching the format string
+ *
+ * This is a convenience function that calls audit_log_start,
+ * audit_log_vformat, and audit_log_end. It may be called
+ * in any context.
+ */
+void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
const char *fmt, ...)
{
struct audit_buffer *ab;
audit_log_end(ab);
}
}
+
+EXPORT_SYMBOL(audit_log_start);
+EXPORT_SYMBOL(audit_log_end);
+EXPORT_SYMBOL(audit_log_format);
+EXPORT_SYMBOL(audit_log);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff