* Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
* System-call specific features have moved to auditsc.c
*
- * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
+ * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
*/
#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>
+#include <linux/selinux.h>
+#include <linux/inotify.h>
+#include <linux/freezer.h>
+#include <linux/tty.h>
+
+#include "audit.h"
/* No auditing will take place until audit_initialized != 0.
* (Initialization happens after skb_init is called.) */
static int audit_initialized;
-/* No syscall auditing will take place unless audit_enabled != 0. */
+/* 0 - no auditing
+ * 1 - auditing enabled
+ * 2 - auditing enabled and configuration is locked/unchangeable. */
int audit_enabled;
/* Default state when kernel boots without any parameters. */
* 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;
pid_t audit_sig_pid = -1;
+u32 audit_sig_sid = 0;
/* Records can be lost in several ways:
0) [suppressed in audit_alloc]
/* The netlink socket. */
static struct sock *audit_sock;
+/* Inotify handle. */
+struct inotify_handle *audit_ih;
+
+/* Hash for inode-based rules */
+struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
+
/* The audit_freelist is a list of pre-allocated audit buffers (if more
* 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;
static struct task_struct *kauditd_task;
static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
+static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
-/* There are three lists of rules -- one to search at task creation
- * time, one to search at syscall entry time, and another to search at
- * syscall exit time. */
-static LIST_HEAD(audit_tsklist);
-static LIST_HEAD(audit_entlist);
-static LIST_HEAD(audit_extlist);
-
-/* 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 */
-static DECLARE_MUTEX(audit_netlink_sem);
+/* Serialize requests from userspace. */
+static DEFINE_MUTEX(audit_cmd_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 */
+ gfp_t gfp_mask;
};
static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
{
- struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data;
+ struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
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)
+static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid)
{
- int old = audit_rate_limit;
- audit_rate_limit = limit;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
- "audit_rate_limit=%d old=%d by auid %u",
- audit_rate_limit, old, loginuid);
- return old;
+ int res, rc = 0, old = audit_rate_limit;
+
+ /* check if we are locked */
+ if (audit_enabled == 2)
+ res = 0;
+ else
+ res = 1;
+
+ if (sid) {
+ char *ctx = NULL;
+ u32 len;
+ if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_rate_limit=%d old=%d by auid=%u"
+ " subj=%s res=%d",
+ limit, old, loginuid, ctx, res);
+ kfree(ctx);
+ } else
+ res = 0; /* Something weird, deny request */
+ }
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_rate_limit=%d old=%d by auid=%u res=%d",
+ limit, old, loginuid, res);
+
+ /* If we are allowed, make the change */
+ if (res == 1)
+ audit_rate_limit = limit;
+ /* Not allowed, update reason */
+ else if (rc == 0)
+ rc = -EPERM;
+ return rc;
}
-static int audit_set_backlog_limit(int limit, uid_t loginuid)
+static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid)
{
- int old = audit_backlog_limit;
- audit_backlog_limit = limit;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
- "audit_backlog_limit=%d old=%d by auid %u",
- audit_backlog_limit, old, loginuid);
- return old;
+ int res, rc = 0, old = audit_backlog_limit;
+
+ /* check if we are locked */
+ if (audit_enabled == 2)
+ res = 0;
+ else
+ res = 1;
+
+ if (sid) {
+ char *ctx = NULL;
+ u32 len;
+ if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_backlog_limit=%d old=%d by auid=%u"
+ " subj=%s res=%d",
+ limit, old, loginuid, ctx, res);
+ kfree(ctx);
+ } else
+ res = 0; /* Something weird, deny request */
+ }
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_backlog_limit=%d old=%d by auid=%u res=%d",
+ limit, old, loginuid, res);
+
+ /* If we are allowed, make the change */
+ if (res == 1)
+ audit_backlog_limit = limit;
+ /* Not allowed, update reason */
+ else if (rc == 0)
+ rc = -EPERM;
+ return rc;
}
-static int audit_set_enabled(int state, uid_t loginuid)
+static int audit_set_enabled(int state, uid_t loginuid, u32 sid)
{
- int old = audit_enabled;
- if (state != 0 && state != 1)
+ int res, rc = 0, old = audit_enabled;
+
+ if (state < 0 || state > 2)
return -EINVAL;
- audit_enabled = state;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
- "audit_enabled=%d old=%d by auid %u",
- audit_enabled, old, loginuid);
- return old;
+
+ /* check if we are locked */
+ if (audit_enabled == 2)
+ res = 0;
+ else
+ res = 1;
+
+ if (sid) {
+ char *ctx = NULL;
+ u32 len;
+ if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_enabled=%d old=%d by auid=%u"
+ " subj=%s res=%d",
+ state, old, loginuid, ctx, res);
+ kfree(ctx);
+ } else
+ res = 0; /* Something weird, deny request */
+ }
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_enabled=%d old=%d by auid=%u res=%d",
+ state, old, loginuid, res);
+
+ /* If we are allowed, make the change */
+ if (res == 1)
+ audit_enabled = state;
+ /* Not allowed, update reason */
+ else if (rc == 0)
+ rc = -EPERM;
+ return rc;
}
-static int audit_set_failure(int state, uid_t loginuid)
+static int audit_set_failure(int state, uid_t loginuid, u32 sid)
{
- int old = audit_failure;
+ int res, rc = 0, old = audit_failure;
+
if (state != AUDIT_FAIL_SILENT
&& state != AUDIT_FAIL_PRINTK
&& state != AUDIT_FAIL_PANIC)
return -EINVAL;
- audit_failure = state;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
- "audit_failure=%d old=%d by auid %u",
- audit_failure, old, loginuid);
- return old;
+
+ /* check if we are locked */
+ if (audit_enabled == 2)
+ res = 0;
+ else
+ res = 1;
+
+ if (sid) {
+ char *ctx = NULL;
+ u32 len;
+ if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_failure=%d old=%d by auid=%u"
+ " subj=%s res=%d",
+ state, old, loginuid, ctx, res);
+ kfree(ctx);
+ } else
+ res = 0; /* Something weird, deny request */
+ }
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_failure=%d old=%d by auid=%u res=%d",
+ state, old, loginuid, res);
+
+ /* If we are allowed, make the change */
+ if (res == 1)
+ audit_failure = state;
+ /* Not allowed, update reason */
+ else if (rc == 0)
+ rc = -EPERM;
+ return rc;
}
-int kauditd_thread(void *dummy)
+static int kauditd_thread(void *dummy)
{
struct sk_buff *skb;
- while (1) {
+ set_freezable();
+ while (!kthread_should_stop()) {
skb = skb_dequeue(&audit_skb_queue);
+ wake_up(&audit_backlog_wait);
if (skb) {
if (audit_pid) {
int err = netlink_unicast(audit_sock, skb, audit_pid, 0);
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;
}
-void audit_send_reply(int pid, int seq, int type, int done, int multi,
- void *payload, int size)
+static int audit_prepare_user_tty(pid_t pid, uid_t loginuid)
+{
+ struct task_struct *tsk;
+ int err;
+
+ read_lock(&tasklist_lock);
+ tsk = find_task_by_pid(pid);
+ err = -ESRCH;
+ if (!tsk)
+ goto out;
+ err = 0;
+
+ spin_lock_irq(&tsk->sighand->siglock);
+ if (!tsk->signal->audit_tty)
+ err = -EPERM;
+ spin_unlock_irq(&tsk->sighand->siglock);
+ if (err)
+ goto out;
+
+ tty_audit_push_task(tsk, loginuid);
+out:
+ read_unlock(&tasklist_lock);
+ return err;
+}
+
+int audit_send_list(void *_dest)
+{
+ struct audit_netlink_list *dest = _dest;
+ int pid = dest->pid;
+ struct sk_buff *skb;
+
+ /* wait for parent to finish and send an ACK */
+ mutex_lock(&audit_cmd_mutex);
+ mutex_unlock(&audit_cmd_mutex);
+
+ while ((skb = __skb_dequeue(&dest->q)) != NULL)
+ netlink_unicast(audit_sock, skb, pid, 0);
+
+ kfree(dest);
+
+ return 0;
+}
+
+struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
+ int multi, void *payload, int size)
{
struct sk_buff *skb;
struct nlmsghdr *nlh;
skb = alloc_skb(len, GFP_KERNEL);
if (!skb)
- return;
+ return NULL;
nlh = NLMSG_PUT(skb, pid, seq, t, size);
nlh->nlmsg_flags = flags;
data = NLMSG_DATA(nlh);
memcpy(data, payload, size);
+ return skb;
+
+nlmsg_failure: /* Used by NLMSG_PUT */
+ if (skb)
+ kfree_skb(skb);
+ return NULL;
+}
+/**
+ * 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)
+{
+ struct sk_buff *skb;
+ skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
+ if (!skb)
+ return;
/* Ignore failure. It'll only happen if the sender goes away,
because our timeout is set to infinite. */
netlink_unicast(audit_sock, skb, pid, 0);
return;
-
-nlmsg_failure: /* Used by NLMSG_PUT */
- if (skb)
- kfree_skb(skb);
}
/*
* Check for appropriate CAP_AUDIT_ capabilities on incoming audit
* control messages.
*/
-static int audit_netlink_ok(kernel_cap_t eff_cap, u16 msg_type)
+static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
{
int err = 0;
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))
+ case AUDIT_TTY_GET:
+ case AUDIT_TTY_SET:
+ if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
err = -EPERM;
break;
case AUDIT_USER:
- case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
- if (!cap_raised(eff_cap, CAP_AUDIT_WRITE))
+ case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
+ case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
+ if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
err = -EPERM;
break;
default: /* bad msg */
static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
- u32 uid, pid, seq;
+ u32 uid, pid, seq, sid;
void *data;
struct audit_status *status_get, status_set;
int err;
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
uid_t loginuid; /* loginuid of sender */
- struct audit_sig_info sig_data;
+ struct audit_sig_info *sig_data;
+ char *ctx;
+ u32 len;
- err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type);
+ err = audit_netlink_ok(skb, msg_type);
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)) {
pid = NETLINK_CREDS(skb)->pid;
uid = NETLINK_CREDS(skb)->uid;
loginuid = NETLINK_CB(skb).loginuid;
+ sid = NETLINK_CB(skb).sid;
seq = nlh->nlmsg_seq;
data = NLMSG_DATA(nlh);
return -EINVAL;
status_get = (struct audit_status *)data;
if (status_get->mask & AUDIT_STATUS_ENABLED) {
- err = audit_set_enabled(status_get->enabled, loginuid);
+ err = audit_set_enabled(status_get->enabled,
+ loginuid, sid);
if (err < 0) return err;
}
if (status_get->mask & AUDIT_STATUS_FAILURE) {
- err = audit_set_failure(status_get->failure, loginuid);
+ err = audit_set_failure(status_get->failure,
+ loginuid, sid);
if (err < 0) return err;
}
if (status_get->mask & AUDIT_STATUS_PID) {
int old = audit_pid;
+ if (sid) {
+ if ((err = selinux_sid_to_string(
+ sid, &ctx, &len)))
+ return err;
+ else
+ audit_log(NULL, GFP_KERNEL,
+ AUDIT_CONFIG_CHANGE,
+ "audit_pid=%d old=%d by auid=%u subj=%s",
+ status_get->pid, old,
+ loginuid, ctx);
+ kfree(ctx);
+ } else
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "audit_pid=%d old=%d by auid=%u",
+ status_get->pid, old, loginuid);
audit_pid = status_get->pid;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
- "audit_pid=%d old=%d by auid %u",
- audit_pid, old, loginuid);
}
if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
- audit_set_rate_limit(status_get->rate_limit, loginuid);
+ err = audit_set_rate_limit(status_get->rate_limit,
+ loginuid, sid);
if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
- audit_set_backlog_limit(status_get->backlog_limit,
- loginuid);
+ err = audit_set_backlog_limit(status_get->backlog_limit,
+ loginuid, sid);
break;
case AUDIT_USER:
- case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
- ab = audit_log_start(NULL, msg_type);
- if (!ab)
- break; /* audit_panic has been called */
- audit_log_format(ab,
- "user pid=%d uid=%u auid=%u"
- " msg='%.1024s'",
- pid, uid, loginuid, (char *)data);
- audit_set_pid(ab, pid);
- audit_log_end(ab);
+ 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;
+
+ err = audit_filter_user(&NETLINK_CB(skb), msg_type);
+ if (err == 1) {
+ err = 0;
+ if (msg_type == AUDIT_USER_TTY) {
+ err = audit_prepare_user_tty(pid, loginuid);
+ if (err)
+ break;
+ }
+ ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
+ if (ab) {
+ audit_log_format(ab,
+ "user pid=%d uid=%u auid=%u",
+ pid, uid, loginuid);
+ if (sid) {
+ if (selinux_sid_to_string(
+ sid, &ctx, &len)) {
+ audit_log_format(ab,
+ " ssid=%u", sid);
+ /* Maybe call audit_panic? */
+ } else
+ audit_log_format(ab,
+ " subj=%s", ctx);
+ kfree(ctx);
+ }
+ if (msg_type != AUDIT_USER_TTY)
+ audit_log_format(ab, " msg='%.1024s'",
+ (char *)data);
+ else {
+ int size;
+
+ audit_log_format(ab, " msg=");
+ size = nlmsg_len(nlh);
+ audit_log_n_untrustedstring(ab, size,
+ data);
+ }
+ audit_set_pid(ab, pid);
+ audit_log_end(ab);
+ }
+ }
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;
+ if (audit_enabled == 2) {
+ ab = audit_log_start(NULL, GFP_KERNEL,
+ AUDIT_CONFIG_CHANGE);
+ if (ab) {
+ audit_log_format(ab,
+ "pid=%d uid=%u auid=%u",
+ pid, uid, loginuid);
+ if (sid) {
+ if (selinux_sid_to_string(
+ sid, &ctx, &len)) {
+ audit_log_format(ab,
+ " ssid=%u", sid);
+ /* Maybe call audit_panic? */
+ } else
+ audit_log_format(ab,
+ " subj=%s", ctx);
+ kfree(ctx);
+ }
+ audit_log_format(ab, " audit_enabled=%d res=0",
+ audit_enabled);
+ audit_log_end(ab);
+ }
+ return -EPERM;
+ }
/* 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, sid);
+ break;
+ case AUDIT_ADD_RULE:
+ case AUDIT_DEL_RULE:
+ if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
+ return -EINVAL;
+ if (audit_enabled == 2) {
+ ab = audit_log_start(NULL, GFP_KERNEL,
+ AUDIT_CONFIG_CHANGE);
+ if (ab) {
+ audit_log_format(ab,
+ "pid=%d uid=%u auid=%u",
+ pid, uid, loginuid);
+ if (sid) {
+ if (selinux_sid_to_string(
+ sid, &ctx, &len)) {
+ audit_log_format(ab,
+ " ssid=%u", sid);
+ /* Maybe call audit_panic? */
+ } else
+ audit_log_format(ab,
+ " subj=%s", ctx);
+ kfree(ctx);
+ }
+ audit_log_format(ab, " audit_enabled=%d res=0",
+ audit_enabled);
+ audit_log_end(ab);
+ }
+ return -EPERM;
+ }
+ /* fallthrough */
+ case AUDIT_LIST_RULES:
+ err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
+ uid, seq, data, nlmsg_len(nlh),
+ loginuid, sid);
break;
case AUDIT_SIGNAL_INFO:
- sig_data.uid = audit_sig_uid;
- sig_data.pid = audit_sig_pid;
+ err = selinux_sid_to_string(audit_sig_sid, &ctx, &len);
+ if (err)
+ return err;
+ sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
+ if (!sig_data) {
+ kfree(ctx);
+ return -ENOMEM;
+ }
+ sig_data->uid = audit_sig_uid;
+ sig_data->pid = audit_sig_pid;
+ memcpy(sig_data->ctx, ctx, len);
+ kfree(ctx);
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
- 0, 0, &sig_data, sizeof(sig_data));
+ 0, 0, sig_data, sizeof(*sig_data) + len);
+ kfree(sig_data);
+ break;
+ case AUDIT_TTY_GET: {
+ struct audit_tty_status s;
+ struct task_struct *tsk;
+
+ read_lock(&tasklist_lock);
+ tsk = find_task_by_pid(pid);
+ if (!tsk)
+ err = -ESRCH;
+ else {
+ spin_lock_irq(&tsk->sighand->siglock);
+ s.enabled = tsk->signal->audit_tty != 0;
+ spin_unlock_irq(&tsk->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
+ audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_TTY_GET, 0, 0,
+ &s, sizeof(s));
break;
+ }
+ case AUDIT_TTY_SET: {
+ struct audit_tty_status *s;
+ struct task_struct *tsk;
+
+ if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
+ return -EINVAL;
+ s = data;
+ if (s->enabled != 0 && s->enabled != 1)
+ return -EINVAL;
+ read_lock(&tasklist_lock);
+ tsk = find_task_by_pid(pid);
+ if (!tsk)
+ err = -ESRCH;
+ else {
+ spin_lock_irq(&tsk->sighand->siglock);
+ tsk->signal->audit_tty = s->enabled != 0;
+ spin_unlock_irq(&tsk->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
+ break;
+ }
default:
err = -EINVAL;
break;
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;
u32 rlen;
while (skb->len >= NLMSG_SPACE(0)) {
- nlh = (struct nlmsghdr *)skb->data;
+ nlh = nlmsg_hdr(skb);
if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
return;
rlen = NLMSG_ALIGN(nlh->nlmsg_len);
}
/* Receive messages from netlink socket. */
-static void audit_receive(struct sock *sk, int length)
+static void audit_receive(struct sk_buff *skb)
{
- struct sk_buff *skb;
- unsigned int qlen;
-
- down(&audit_netlink_sem);
-
- 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_lock(&audit_cmd_mutex);
+ audit_receive_skb(skb);
+ mutex_unlock(&audit_cmd_mutex);
}
+#ifdef CONFIG_AUDITSYSCALL
+static const struct inotify_operations audit_inotify_ops = {
+ .handle_event = audit_handle_ievent,
+ .destroy_watch = audit_free_parent,
+};
+#endif
/* Initialize audit support at boot time. */
static int __init audit_init(void)
{
+ int i;
+
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(&init_net, NETLINK_AUDIT, 0,
+ audit_receive, NULL, 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_log(NULL, AUDIT_KERNEL, "initialized");
+
+ /* Register the callback with selinux. This callback will be invoked
+ * when a new policy is loaded. */
+ selinux_audit_set_callback(&selinux_audit_rule_update);
+
+ audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
+
+#ifdef CONFIG_AUDITSYSCALL
+ audit_ih = inotify_init(&audit_inotify_ops);
+ if (IS_ERR(audit_ih))
+ audit_panic("cannot initialize inotify handle");
+#endif
+
+ for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
+ INIT_LIST_HEAD(&audit_inode_hash[i]);
+
return 0;
}
__initcall(audit_init);
audit_initialized ? "" : " (after initialization)");
if (audit_initialized)
audit_enabled = audit_default;
- return 0;
+ return 1;
}
__setup("audit=", audit_enable);
kfree_skb(ab->skb);
spin_lock_irqsave(&audit_freelist_lock, flags);
- if (++audit_freelist_count > AUDIT_MAXFREE)
+ if (audit_freelist_count > AUDIT_MAXFREE)
kfree(ab);
- else
+ else {
+ audit_freelist_count++;
list_add(&ab->list, &audit_freelist);
+ }
spin_unlock_irqrestore(&audit_freelist_lock, flags);
}
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;
goto err;
ab->ctx = ctx;
+ ab->gfp_mask = gfp_mask;
nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0));
nlh->nlmsg_type = type;
nlh->nlmsg_flags = 0;
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 DEFINE_SPINLOCK(serial_lock);
+ 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,
* syscall, then the syscall is marked as auditable and an audit record
* 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 type)
+
+/**
+ * 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 (audit_backlog_limit
- && skb_queue_len(&audit_skb_queue) > audit_backlog_limit) {
+ if (unlikely(audit_filter_type(type)))
+ return NULL;
+
+ if (gfp_mask & __GFP_WAIT)
+ reserve = 0;
+ else
+ reserve = 5; /* Allow atomic callers to go up to five
+ entries over the normal backlog limit */
+
+ while (audit_backlog_limit
+ && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
+ 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);
+ add_wait_queue(&audit_backlog_wait, &wait);
+
+ if (audit_backlog_limit &&
+ skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
+ schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
+
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&audit_backlog_wait, &wait);
+ continue;
+ }
if (audit_rate_check())
printk(KERN_WARNING
"audit: audit_backlog=%d > "
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;
}
- ab = audit_buffer_alloc(ctx, GFP_ATOMIC, type);
+ ab = audit_buffer_alloc(ctx, gfp_mask, type);
if (!ab) {
audit_log_lost("out of memory in audit_log_start");
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.
{
struct sk_buff *skb = ab->skb;
int ret = pskb_expand_head(skb, skb_headroom(skb), extra,
- GFP_ATOMIC);
+ ab->gfp_mask);
if (ret < 0) {
audit_log_lost("out of memory in audit_expand");
return 0;
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)
{
goto out;
}
va_copy(args2, args);
- len = vsnprintf(skb->tail, avail, fmt, args);
+ len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
if (len >= avail) {
/* 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);
+ len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
}
if (len > 0)
skb_put(skb, len);
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;
struct sk_buff *skb;
static const unsigned char *hex = "0123456789ABCDEF";
+ if (!ab)
+ return;
+
BUG_ON(!ab->skb);
skb = ab->skb;
avail = skb_tailroom(skb);
return;
}
- ptr = skb->tail;
+ ptr = skb_tail_pointer(skb);
for (i=0; i<len; i++) {
*ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
*ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
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,
+/*
+ * Format a string of no more than slen characters into the audit buffer,
+ * enclosed in quote marks.
+ */
+static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
+ const char *string)
+{
+ int avail, new_len;
+ unsigned char *ptr;
+ struct sk_buff *skb;
+
+ if (!ab)
+ return;
+
+ BUG_ON(!ab->skb);
+ skb = ab->skb;
+ avail = skb_tailroom(skb);
+ new_len = slen + 3; /* enclosing quotes + null terminator */
+ if (new_len > avail) {
+ avail = audit_expand(ab, new_len);
+ if (!avail)
+ return;
+ }
+ ptr = skb_tail_pointer(skb);
+ *ptr++ = '"';
+ memcpy(ptr, string, slen);
+ ptr += slen;
+ *ptr++ = '"';
+ *ptr = 0;
+ skb_put(skb, slen + 2); /* don't include null terminator */
+}
+
+/**
+ * audit_log_n_untrustedstring - log a string that may contain random characters
+ * @ab: audit_buffer
+ * @len: lenth of string (not including trailing null)
+ * @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). */
-void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
+ * Strings that are escaped are printed in hex (2 digits per char).
+ *
+ * The caller specifies the number of characters in the string to log, which may
+ * or may not be the entire string.
+ */
+const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len,
+ const char *string)
{
- const unsigned char *p = string;
+ const unsigned char *p;
- while (*p) {
+ for (p = string; p < (const unsigned char *)string + len && *p; p++) {
if (*p == '"' || *p < 0x21 || *p > 0x7f) {
- audit_log_hex(ab, string, strlen(string));
- return;
+ audit_log_hex(ab, string, len);
+ return string + len + 1;
}
- p++;
}
- audit_log_format(ab, "\"%s\"", string);
+ audit_log_n_string(ab, len, string);
+ return p + 1;
+}
+
+/**
+ * audit_log_untrustedstring - log a string that may contain random characters
+ * @ab: audit_buffer
+ * @string: string to be logged
+ *
+ * Same as audit_log_n_untrustedstring(), except that strlen is used to
+ * determine string length.
+ */
+const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
+{
+ return audit_log_n_untrustedstring(ab, strlen(string), string);
}
/* This is a helper-function to print the escaped d_path */
audit_log_format(ab, " %s", prefix);
/* We will allow 11 spaces for ' (deleted)' to be appended */
- path = kmalloc(PATH_MAX+11, GFP_KERNEL);
+ path = kmalloc(PATH_MAX+11, ab->gfp_mask);
if (!path) {
audit_log_format(ab, "<no memory>");
return;
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)
audit_log_lost("rate limit exceeded");
} else {
if (audit_pid) {
- struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data;
+ struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
skb_queue_tail(&audit_skb_queue, ab->skb);
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 type, const char *fmt, ...)
+/**
+ * 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;
va_list args;
- ab = audit_log_start(ctx, type);
+ ab = audit_log_start(ctx, gfp_mask, type);
if (ab) {
va_start(args, fmt);
audit_log_vformat(ab, fmt, args);
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