* 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
*
* Written by Rickard E. (Rik) Faith <faith@redhat.com>
*
- * Goals: 1) Integrate fully with SELinux.
+ * Goals: 1) Integrate fully with Security Modules.
* 2) Minimal run-time overhead:
* a) Minimal when syscall auditing is disabled (audit_enable=0).
* b) Small when syscall auditing is enabled and no audit record
#include <linux/init.h>
#include <asm/types.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
#include <linux/mm.h>
-#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/slab.h>
#include <linux/err.h>
#include <linux/kthread.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <linux/skbuff.h>
+#ifdef CONFIG_SECURITY
+#include <linux/security.h>
+#endif
#include <linux/netlink.h>
-#include <linux/selinux.h>
+#include <linux/freezer.h>
+#include <linux/tty.h>
#include "audit.h"
-/* No auditing will take place until audit_initialized != 0.
+/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
* (Initialization happens after skb_init is called.) */
+#define AUDIT_DISABLED -1
+#define AUDIT_UNINITIALIZED 0
+#define AUDIT_INITIALIZED 1
static int audit_initialized;
-/* No syscall auditing will take place unless audit_enabled != 0. */
+#define AUDIT_OFF 0
+#define AUDIT_ON 1
+#define AUDIT_LOCKED 2
int audit_enabled;
+int audit_ever_enabled;
+
+EXPORT_SYMBOL_GPL(audit_enabled);
/* Default state when kernel boots without any parameters. */
static int audit_default;
/* If auditing cannot proceed, audit_failure selects what happens. */
static int audit_failure = AUDIT_FAIL_PRINTK;
-/* If audit records are to be written to the netlink socket, audit_pid
- * contains the (non-zero) pid. */
+/*
+ * If audit records are to be written to the netlink socket, audit_pid
+ * contains the pid of the auditd process and audit_nlk_pid contains
+ * the pid to use to send netlink messages to that process.
+ */
int audit_pid;
+static int audit_nlk_pid;
/* 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
/* 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;
+/* 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 LIST_HEAD(audit_freelist);
static struct sk_buff_head audit_skb_queue;
+/* queue of skbs to send to auditd when/if it comes back */
+static struct sk_buff_head audit_skb_hold_queue;
static struct task_struct *kauditd_task;
static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
-/* 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 */
-DEFINE_MUTEX(audit_netlink_mutex);
+/* Serialize requests from userspace. */
+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
gfp_t gfp_mask;
};
+struct audit_reply {
+ int pid;
+ struct sk_buff *skb;
+};
+
static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
{
- struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data;
- nlh->nlmsg_pid = pid;
+ if (ab) {
+ struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
+ nlh->nlmsg_pid = pid;
+ }
}
void audit_panic(const char *message)
case AUDIT_FAIL_SILENT:
break;
case AUDIT_FAIL_PRINTK:
- printk(KERN_ERR "audit: %s\n", message);
+ if (printk_ratelimit())
+ printk(KERN_ERR "audit: %s\n", message);
break;
case AUDIT_FAIL_PANIC:
- panic("audit: %s\n", message);
+ /* test audit_pid since printk is always losey, why bother? */
+ if (audit_pid)
+ panic("audit: %s\n", message);
break;
}
}
}
if (print) {
- printk(KERN_WARNING
- "audit: audit_lost=%d audit_rate_limit=%d audit_backlog_limit=%d\n",
- atomic_read(&audit_lost),
- audit_rate_limit,
- audit_backlog_limit);
+ if (printk_ratelimit())
+ printk(KERN_WARNING
+ "audit: audit_lost=%d audit_rate_limit=%d "
+ "audit_backlog_limit=%d\n",
+ atomic_read(&audit_lost),
+ audit_rate_limit,
+ audit_backlog_limit);
audit_panic(message);
}
}
-static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid)
+static int audit_log_config_change(char *function_name, int new, int old,
+ uid_t loginuid, u32 sessionid, u32 sid,
+ int allow_changes)
{
- int old = audit_rate_limit;
+ struct audit_buffer *ab;
+ int rc = 0;
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
+ old, loginuid, sessionid);
if (sid) {
char *ctx = NULL;
u32 len;
- int rc;
- if ((rc = selinux_ctxid_to_string(sid, &ctx, &len)))
- return rc;
- else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_rate_limit=%d old=%d by auid=%u subj=%s",
- limit, old, loginuid, ctx);
- kfree(ctx);
- } else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_rate_limit=%d old=%d by auid=%u",
- limit, old, loginuid);
- audit_rate_limit = limit;
- return old;
+
+ rc = security_secid_to_secctx(sid, &ctx, &len);
+ if (rc) {
+ audit_log_format(ab, " sid=%u", sid);
+ allow_changes = 0; /* Something weird, deny request */
+ } else {
+ audit_log_format(ab, " subj=%s", ctx);
+ security_release_secctx(ctx, len);
+ }
+ }
+ audit_log_format(ab, " res=%d", allow_changes);
+ audit_log_end(ab);
+ return rc;
}
-static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid)
+static int audit_do_config_change(char *function_name, int *to_change,
+ int new, uid_t loginuid, u32 sessionid,
+ u32 sid)
{
- int old = audit_backlog_limit;
+ int allow_changes, rc = 0, old = *to_change;
- if (sid) {
- char *ctx = NULL;
- u32 len;
- int rc;
- if ((rc = selinux_ctxid_to_string(sid, &ctx, &len)))
- return rc;
- else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_backlog_limit=%d old=%d by auid=%u subj=%s",
- limit, old, loginuid, ctx);
- kfree(ctx);
- } else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_backlog_limit=%d old=%d by auid=%u",
- limit, old, loginuid);
- audit_backlog_limit = limit;
- return old;
+ /* check if we are locked */
+ if (audit_enabled == AUDIT_LOCKED)
+ allow_changes = 0;
+ else
+ allow_changes = 1;
+
+ if (audit_enabled != AUDIT_OFF) {
+ rc = audit_log_config_change(function_name, new, old, loginuid,
+ sessionid, sid, allow_changes);
+ if (rc)
+ allow_changes = 0;
+ }
+
+ /* If we are allowed, make the change */
+ if (allow_changes == 1)
+ *to_change = new;
+ /* Not allowed, update reason */
+ else if (rc == 0)
+ rc = -EPERM;
+ return rc;
+}
+
+static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
+ u32 sid)
+{
+ return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
+ limit, loginuid, sessionid, sid);
}
-static int audit_set_enabled(int state, uid_t loginuid, u32 sid)
+static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
+ u32 sid)
{
- int old = audit_enabled;
+ return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
+ limit, loginuid, sessionid, sid);
+}
- if (state != 0 && state != 1)
+static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
+{
+ int rc;
+ if (state < AUDIT_OFF || state > AUDIT_LOCKED)
return -EINVAL;
- if (sid) {
- char *ctx = NULL;
- u32 len;
- int rc;
- if ((rc = selinux_ctxid_to_string(sid, &ctx, &len)))
- return rc;
- else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_enabled=%d old=%d by auid=%u subj=%s",
- state, old, loginuid, ctx);
- kfree(ctx);
- } else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_enabled=%d old=%d by auid=%u",
- state, old, loginuid);
- audit_enabled = state;
- return old;
+ rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
+ loginuid, sessionid, sid);
+
+ if (!rc)
+ audit_ever_enabled |= !!state;
+
+ return rc;
}
-static int audit_set_failure(int state, uid_t loginuid, u32 sid)
+static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
{
- int old = audit_failure;
-
if (state != AUDIT_FAIL_SILENT
&& state != AUDIT_FAIL_PRINTK
&& state != AUDIT_FAIL_PANIC)
return -EINVAL;
- if (sid) {
- char *ctx = NULL;
- u32 len;
- int rc;
- if ((rc = selinux_ctxid_to_string(sid, &ctx, &len)))
- return rc;
+ return audit_do_config_change("audit_failure", &audit_failure, state,
+ loginuid, sessionid, sid);
+}
+
+/*
+ * Queue skbs to be sent to auditd when/if it comes back. These skbs should
+ * already have been sent via prink/syslog and so if these messages are dropped
+ * it is not a huge concern since we already passed the audit_log_lost()
+ * notification and stuff. This is just nice to get audit messages during
+ * boot before auditd is running or messages generated while auditd is stopped.
+ * This only holds messages is audit_default is set, aka booting with audit=1
+ * or building your kernel that way.
+ */
+static void audit_hold_skb(struct sk_buff *skb)
+{
+ if (audit_default &&
+ skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
+ skb_queue_tail(&audit_skb_hold_queue, skb);
+ else
+ kfree_skb(skb);
+}
+
+/*
+ * For one reason or another this nlh isn't getting delivered to the userspace
+ * audit daemon, just send it to printk.
+ */
+static void audit_printk_skb(struct sk_buff *skb)
+{
+ struct nlmsghdr *nlh = nlmsg_hdr(skb);
+ char *data = NLMSG_DATA(nlh);
+
+ if (nlh->nlmsg_type != AUDIT_EOE) {
+ if (printk_ratelimit())
+ printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_failure=%d old=%d by auid=%u subj=%s",
- state, old, loginuid, ctx);
- kfree(ctx);
+ audit_log_lost("printk limit exceeded\n");
+ }
+
+ audit_hold_skb(skb);
+}
+
+static void kauditd_send_skb(struct sk_buff *skb)
+{
+ int err;
+ /* take a reference in case we can't send it and we want to hold it */
+ skb_get(skb);
+ err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
+ if (err < 0) {
+ BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
+ printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
+ audit_log_lost("auditd disappeared\n");
+ audit_pid = 0;
+ /* we might get lucky and get this in the next auditd */
+ audit_hold_skb(skb);
} else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_failure=%d old=%d by auid=%u",
- state, old, loginuid);
- audit_failure = state;
- return old;
+ /* drop the extra reference if sent ok */
+ consume_skb(skb);
}
static int kauditd_thread(void *dummy)
{
struct sk_buff *skb;
- while (1) {
+ set_freezable();
+ while (!kthread_should_stop()) {
+ /*
+ * if auditd just started drain the queue of messages already
+ * sent to syslog/printk. remember loss here is ok. we already
+ * called audit_log_lost() if it didn't go out normally. so the
+ * race between the skb_dequeue and the next check for audit_pid
+ * doesn't matter.
+ *
+ * if you ever find kauditd to be too slow we can get a perf win
+ * by doing our own locking and keeping better track if there
+ * are messages in this queue. I don't see the need now, but
+ * in 5 years when I want to play with this again I'll see this
+ * note and still have no friggin idea what i'm thinking today.
+ */
+ if (audit_default && audit_pid) {
+ skb = skb_dequeue(&audit_skb_hold_queue);
+ if (unlikely(skb)) {
+ while (skb && audit_pid) {
+ kauditd_send_skb(skb);
+ skb = skb_dequeue(&audit_skb_hold_queue);
+ }
+ }
+ }
+
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);
- if (err < 0) {
- BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */
- printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
- audit_pid = 0;
- }
- } else {
- printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0));
- kfree_skb(skb);
- }
+ if (audit_pid)
+ kauditd_send_skb(skb);
+ else
+ audit_printk_skb(skb);
} else {
DECLARE_WAITQUEUE(wait, current);
set_current_state(TASK_INTERRUPTIBLE);
return 0;
}
+static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
+{
+ struct task_struct *tsk;
+ int err;
+
+ rcu_read_lock();
+ tsk = find_task_by_vpid(pid);
+ if (!tsk) {
+ rcu_read_unlock();
+ return -ESRCH;
+ }
+ get_task_struct(tsk);
+ rcu_read_unlock();
+ err = tty_audit_push_task(tsk, loginuid, sessionid);
+ put_task_struct(tsk);
+ return err;
+}
+
int audit_send_list(void *_dest)
{
struct audit_netlink_list *dest = _dest;
struct sk_buff *skb;
/* wait for parent to finish and send an ACK */
- mutex_lock(&audit_netlink_mutex);
- mutex_unlock(&audit_netlink_mutex);
+ mutex_lock(&audit_cmd_mutex);
+ mutex_unlock(&audit_cmd_mutex);
while ((skb = __skb_dequeue(&dest->q)) != NULL)
netlink_unicast(audit_sock, skb, pid, 0);
}
struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
- int multi, void *payload, int size)
+ int multi, const void *payload, int size)
{
struct sk_buff *skb;
struct nlmsghdr *nlh;
- int len = NLMSG_SPACE(size);
void *data;
int flags = multi ? NLM_F_MULTI : 0;
int t = done ? NLMSG_DONE : type;
- skb = alloc_skb(len, GFP_KERNEL);
+ skb = nlmsg_new(size, GFP_KERNEL);
if (!skb)
return NULL;
- nlh = NLMSG_PUT(skb, pid, seq, t, size);
- nlh->nlmsg_flags = flags;
- data = NLMSG_DATA(nlh);
+ nlh = NLMSG_NEW(skb, pid, seq, t, size, flags);
+ data = NLMSG_DATA(nlh);
memcpy(data, payload, size);
return skb;
-nlmsg_failure: /* Used by NLMSG_PUT */
+nlmsg_failure: /* Used by NLMSG_NEW */
if (skb)
kfree_skb(skb);
return NULL;
}
+static int audit_send_reply_thread(void *arg)
+{
+ struct audit_reply *reply = (struct audit_reply *)arg;
+
+ mutex_lock(&audit_cmd_mutex);
+ mutex_unlock(&audit_cmd_mutex);
+
+ /* Ignore failure. It'll only happen if the sender goes away,
+ because our timeout is set to infinite. */
+ netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
+ kfree(reply);
+ return 0;
+}
/**
* audit_send_reply - send an audit reply message via netlink
* @pid: process id to send reply to
* 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)
+static void audit_send_reply(int pid, int seq, int type, int done, int multi,
+ const void *payload, int size)
{
- struct sk_buff *skb;
+ struct sk_buff *skb;
+ struct task_struct *tsk;
+ struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
+ GFP_KERNEL);
+
+ if (!reply)
+ return;
+
skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
if (!skb)
+ goto out;
+
+ reply->pid = pid;
+ reply->skb = skb;
+
+ tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
+ if (!IS_ERR(tsk))
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;
+ kfree_skb(skb);
+out:
+ kfree(reply);
}
/*
* 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;
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:
+ case AUDIT_TRIM:
+ case AUDIT_MAKE_EQUIV:
+ if (!capable(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))
+ case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
+ case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
+ if (!capable(CAP_AUDIT_WRITE))
err = -EPERM;
break;
default: /* bad msg */
return err;
}
+static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
+ u32 pid, u32 uid, uid_t auid, u32 ses,
+ u32 sid)
+{
+ int rc = 0;
+ char *ctx = NULL;
+ u32 len;
+
+ if (!audit_enabled) {
+ *ab = NULL;
+ return rc;
+ }
+
+ *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
+ audit_log_format(*ab, "pid=%d uid=%u auid=%u ses=%u",
+ pid, uid, auid, ses);
+ if (sid) {
+ rc = security_secid_to_secctx(sid, &ctx, &len);
+ if (rc)
+ audit_log_format(*ab, " ssid=%u", sid);
+ else {
+ audit_log_format(*ab, " subj=%s", ctx);
+ security_release_secctx(ctx, len);
+ }
+ }
+
+ return rc;
+}
+
static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
u32 uid, pid, seq, sid;
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
uid_t loginuid; /* loginuid of sender */
- struct audit_sig_info sig_data;
+ u32 sessionid;
+ struct audit_sig_info *sig_data;
+ char *ctx = NULL;
+ u32 len;
- err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type);
+ err = audit_netlink_ok(skb, msg_type);
if (err)
return err;
pid = NETLINK_CREDS(skb)->pid;
uid = NETLINK_CREDS(skb)->uid;
- loginuid = NETLINK_CB(skb).loginuid;
- sid = NETLINK_CB(skb).sid;
+ loginuid = audit_get_loginuid(current);
+ sessionid = audit_get_sessionid(current);
+ security_task_getsecid(current, &sid);
seq = nlh->nlmsg_seq;
data = NLMSG_DATA(nlh);
status_get = (struct audit_status *)data;
if (status_get->mask & AUDIT_STATUS_ENABLED) {
err = audit_set_enabled(status_get->enabled,
- loginuid, sid);
- if (err < 0) return err;
+ loginuid, sessionid, sid);
+ if (err < 0)
+ return err;
}
if (status_get->mask & AUDIT_STATUS_FAILURE) {
err = audit_set_failure(status_get->failure,
- loginuid, sid);
- if (err < 0) return err;
+ loginuid, sessionid, sid);
+ if (err < 0)
+ return err;
}
if (status_get->mask & AUDIT_STATUS_PID) {
- int old = audit_pid;
- if (sid) {
- char *ctx = NULL;
- u32 len;
- int rc;
- if ((rc = selinux_ctxid_to_string(
- sid, &ctx, &len)))
- return rc;
- 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;
+ int new_pid = status_get->pid;
+
+ if (audit_enabled != AUDIT_OFF)
+ audit_log_config_change("audit_pid", new_pid,
+ audit_pid, loginuid,
+ sessionid, sid, 1);
+
+ audit_pid = new_pid;
+ audit_nlk_pid = NETLINK_CB(skb).pid;
+ }
+ if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
+ err = audit_set_rate_limit(status_get->rate_limit,
+ loginuid, sessionid, sid);
+ if (err < 0)
+ return err;
}
- if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
- 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, sid);
+ err = audit_set_backlog_limit(status_get->backlog_limit,
+ loginuid, sessionid, sid);
break;
case AUDIT_USER:
- case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
- case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2:
+ 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);
+ err = audit_filter_user(&NETLINK_CB(skb));
if (err == 1) {
err = 0;
- 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) {
- char *ctx = NULL;
- u32 len;
- if (selinux_ctxid_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) {
+ err = audit_prepare_user_tty(pid, loginuid,
+ sessionid);
+ if (err)
+ break;
+ }
+ audit_log_common_recv_msg(&ab, msg_type, pid, uid,
+ loginuid, sessionid, sid);
+
+ if (msg_type != AUDIT_USER_TTY)
audit_log_format(ab, " msg='%.1024s'",
- (char *)data);
- audit_set_pid(ab, pid);
- audit_log_end(ab);
+ (char *)data);
+ else {
+ int size;
+
+ audit_log_format(ab, " msg=");
+ size = nlmsg_len(nlh);
+ if (size > 0 &&
+ ((unsigned char *)data)[size - 1] == '\0')
+ size--;
+ audit_log_n_untrustedstring(ab, data, size);
}
+ audit_set_pid(ab, pid);
+ audit_log_end(ab);
}
break;
case AUDIT_ADD:
case AUDIT_DEL:
if (nlmsg_len(nlh) < sizeof(struct audit_rule))
return -EINVAL;
+ if (audit_enabled == AUDIT_LOCKED) {
+ audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
+ uid, loginuid, sessionid, sid);
+
+ 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,
+ err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
uid, seq, data, nlmsg_len(nlh),
- loginuid, sid);
+ loginuid, sessionid, sid);
break;
case AUDIT_ADD_RULE:
case AUDIT_DEL_RULE:
if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
return -EINVAL;
+ if (audit_enabled == AUDIT_LOCKED) {
+ audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
+ uid, loginuid, sessionid, sid);
+
+ 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,
+ err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
uid, seq, data, nlmsg_len(nlh),
- loginuid, sid);
+ loginuid, sessionid, sid);
+ break;
+ case AUDIT_TRIM:
+ audit_trim_trees();
+
+ audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
+ uid, loginuid, sessionid, sid);
+
+ audit_log_format(ab, " op=trim res=1");
+ audit_log_end(ab);
break;
+ case AUDIT_MAKE_EQUIV: {
+ void *bufp = data;
+ u32 sizes[2];
+ size_t msglen = nlmsg_len(nlh);
+ char *old, *new;
+
+ err = -EINVAL;
+ if (msglen < 2 * sizeof(u32))
+ break;
+ memcpy(sizes, bufp, 2 * sizeof(u32));
+ bufp += 2 * sizeof(u32);
+ msglen -= 2 * sizeof(u32);
+ old = audit_unpack_string(&bufp, &msglen, sizes[0]);
+ if (IS_ERR(old)) {
+ err = PTR_ERR(old);
+ break;
+ }
+ new = audit_unpack_string(&bufp, &msglen, sizes[1]);
+ if (IS_ERR(new)) {
+ err = PTR_ERR(new);
+ kfree(old);
+ break;
+ }
+ /* OK, here comes... */
+ err = audit_tag_tree(old, new);
+
+ audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
+ uid, loginuid, sessionid, sid);
+
+ audit_log_format(ab, " op=make_equiv old=");
+ audit_log_untrustedstring(ab, old);
+ audit_log_format(ab, " new=");
+ audit_log_untrustedstring(ab, new);
+ audit_log_format(ab, " res=%d", !err);
+ audit_log_end(ab);
+ kfree(old);
+ kfree(new);
+ break;
+ }
case AUDIT_SIGNAL_INFO:
- sig_data.uid = audit_sig_uid;
- sig_data.pid = audit_sig_pid;
- audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
- 0, 0, &sig_data, sizeof(sig_data));
+ len = 0;
+ if (audit_sig_sid) {
+ err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
+ if (err)
+ return err;
+ }
+ sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
+ if (!sig_data) {
+ if (audit_sig_sid)
+ security_release_secctx(ctx, len);
+ return -ENOMEM;
+ }
+ sig_data->uid = audit_sig_uid;
+ sig_data->pid = audit_sig_pid;
+ if (audit_sig_sid) {
+ memcpy(sig_data->ctx, ctx, len);
+ security_release_secctx(ctx, len);
+ }
+ audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
+ 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;
+ unsigned long flags;
+
+ rcu_read_lock();
+ tsk = find_task_by_vpid(pid);
+ if (tsk && lock_task_sighand(tsk, &flags)) {
+ s.enabled = tsk->signal->audit_tty != 0;
+ unlock_task_sighand(tsk, &flags);
+ } else
+ err = -ESRCH;
+ rcu_read_unlock();
+
+ if (!err)
+ 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;
+ unsigned long flags;
+
+ if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
+ return -EINVAL;
+ s = data;
+ if (s->enabled != 0 && s->enabled != 1)
+ return -EINVAL;
+ rcu_read_lock();
+ tsk = find_task_by_vpid(pid);
+ if (tsk && lock_task_sighand(tsk, &flags)) {
+ tsk->signal->audit_tty = s->enabled != 0;
+ unlock_task_sighand(tsk, &flags);
+ } else
+ err = -ESRCH;
+ rcu_read_unlock();
break;
+ }
default:
err = -EINVAL;
break;
}
/*
- * 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.
+ * Get message from skb. Each message is processed by audit_receive_msg.
+ * Malformed skbs with wrong length are discarded silently.
*/
static void audit_receive_skb(struct sk_buff *skb)
{
- int err;
- struct nlmsghdr *nlh;
- u32 rlen;
-
- while (skb->len >= NLMSG_SPACE(0)) {
- nlh = (struct nlmsghdr *)skb->data;
- if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
- return;
- rlen = NLMSG_ALIGN(nlh->nlmsg_len);
- if (rlen > skb->len)
- rlen = skb->len;
- if ((err = audit_receive_msg(skb, nlh))) {
+ struct nlmsghdr *nlh;
+ /*
+ * len MUST be signed for NLMSG_NEXT to be able to dec it below 0
+ * if the nlmsg_len was not aligned
+ */
+ int len;
+ int err;
+
+ nlh = nlmsg_hdr(skb);
+ len = skb->len;
+
+ while (NLMSG_OK(nlh, len)) {
+ err = audit_receive_msg(skb, nlh);
+ /* if err or if this message says it wants a response */
+ if (err || (nlh->nlmsg_flags & NLM_F_ACK))
netlink_ack(skb, nlh, err);
- } else if (nlh->nlmsg_flags & NLM_F_ACK)
- netlink_ack(skb, nlh, 0);
- skb_pull(skb, rlen);
+
+ nlh = NLMSG_NEXT(nlh, 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;
-
- 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);
- }
- mutex_unlock(&audit_netlink_mutex);
+ mutex_lock(&audit_cmd_mutex);
+ audit_receive_skb(skb);
+ mutex_unlock(&audit_cmd_mutex);
}
-
/* Initialize audit support at boot time. */
static int __init audit_init(void)
{
+ int i;
+
+ if (audit_initialized == AUDIT_DISABLED)
+ return 0;
+
printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
audit_default ? "enabled" : "disabled");
- audit_sock = netlink_kernel_create(NETLINK_AUDIT, 0, audit_receive,
- THIS_MODULE);
+ 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;
skb_queue_head_init(&audit_skb_queue);
- audit_initialized = 1;
+ skb_queue_head_init(&audit_skb_hold_queue);
+ audit_initialized = AUDIT_INITIALIZED;
audit_enabled = audit_default;
-
- /* 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_ever_enabled |= !!audit_default;
audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
+
+ for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
+ INIT_LIST_HEAD(&audit_inode_hash[i]);
+
return 0;
}
__initcall(audit_init);
static int __init audit_enable(char *str)
{
audit_default = !!simple_strtol(str, NULL, 0);
- printk(KERN_INFO "audit: %s%s\n",
- audit_default ? "enabled" : "disabled",
- audit_initialized ? "" : " (after initialization)");
- if (audit_initialized)
+ if (!audit_default)
+ audit_initialized = AUDIT_DISABLED;
+
+ printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
+
+ if (audit_initialized == AUDIT_INITIALIZED) {
audit_enabled = audit_default;
+ audit_ever_enabled |= !!audit_default;
+ } else if (audit_initialized == AUDIT_UNINITIALIZED) {
+ printk(" (after initialization)");
+ } else {
+ printk(" (until reboot)");
+ }
+ printk("\n");
+
return 1;
}
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);
}
goto err;
}
- ab->skb = alloc_skb(AUDIT_BUFSIZ, gfp_mask);
- if (!ab->skb)
- 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;
- nlh->nlmsg_pid = 0;
- nlh->nlmsg_seq = 0;
+
+ ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
+ if (!ab->skb)
+ goto nlmsg_failure;
+
+ nlh = NLMSG_NEW(ab->skb, 0, 0, type, 0, 0);
+
return ab;
+
+nlmsg_failure: /* Used by NLMSG_NEW */
+ kfree_skb(ab->skb);
+ ab->skb = NULL;
err:
audit_buffer_free(ab);
return NULL;
*/
unsigned int audit_serial(void)
{
- static spinlock_t serial_lock = SPIN_LOCK_UNLOCKED;
+ static DEFINE_SPINLOCK(serial_lock);
static unsigned int serial = 0;
unsigned long flags;
return ret;
}
-static inline void audit_get_stamp(struct audit_context *ctx,
+static inline void audit_get_stamp(struct audit_context *ctx,
struct timespec *t, unsigned int *serial)
{
- if (ctx)
- auditsc_get_stamp(ctx, t, serial);
- else {
+ if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
*t = CURRENT_TIME;
*serial = audit_serial();
}
{
struct audit_buffer *ab = NULL;
struct timespec t;
- unsigned int serial;
+ unsigned int uninitialized_var(serial);
int reserve;
unsigned long timeout_start = jiffies;
- if (!audit_initialized)
+ if (audit_initialized != AUDIT_INITIALIZED)
return NULL;
if (unlikely(audit_filter_type(type)))
if (gfp_mask & __GFP_WAIT)
reserve = 0;
else
- reserve = 5; /* Allow atomic callers to go up to five
+ reserve = 5; /* Allow atomic callers to go up to five
entries over the normal backlog limit */
while (audit_backlog_limit
remove_wait_queue(&audit_backlog_wait, &wait);
continue;
}
- if (audit_rate_check())
+ if (audit_rate_check() && printk_ratelimit())
printk(KERN_WARNING
"audit: audit_backlog=%d > "
"audit_backlog_limit=%d\n",
static inline int audit_expand(struct audit_buffer *ab, int extra)
{
struct sk_buff *skb = ab->skb;
- int ret = pskb_expand_head(skb, skb_headroom(skb), extra,
- ab->gfp_mask);
+ int oldtail = skb_tailroom(skb);
+ int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
+ int newtail = skb_tailroom(skb);
+
if (ret < 0) {
audit_log_lost("out of memory in audit_expand");
return 0;
}
- return skb_tailroom(skb);
+
+ skb->truesize += newtail - oldtail;
+ return newtail;
}
/*
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
avail = audit_expand(ab,
max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
if (!avail)
- goto out;
- len = vsnprintf(skb->tail, avail, fmt, args2);
+ goto out_va_end;
+ len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
}
if (len > 0)
skb_put(skb, len);
+out_va_end:
+ va_end(args2);
out:
return;
}
* 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,
+void audit_log_n_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 */
}
+/*
+ * Format a string of no more than slen characters into the audit buffer,
+ * enclosed in quote marks.
+ */
+void audit_log_n_string(struct audit_buffer *ab, const char *string,
+ size_t slen)
+{
+ 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_string_contains_control - does a string need to be logged in hex
+ * @string: string to be checked
+ * @len: max length of the string to check
+ */
+int audit_string_contains_control(const char *string, size_t len)
+{
+ const unsigned char *p;
+ for (p = string; p < (const unsigned char *)string + len; p++) {
+ if (*p == '"' || *p < 0x21 || *p > 0x7e)
+ return 1;
+ }
+ return 0;
+}
+
/**
- * audit_log_unstrustedstring - log a string that may contain random characters
+ * audit_log_n_untrustedstring - log a string that may contain random characters
* @ab: audit_buffer
+ * @len: length 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).
+ *
+ * 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_untrustedstring(struct audit_buffer *ab, const char *string)
+void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
+ size_t len)
{
- const unsigned char *p = string;
- size_t len = strlen(string);
+ if (audit_string_contains_control(string, len))
+ audit_log_n_hex(ab, string, len);
+ else
+ audit_log_n_string(ab, string, len);
+}
- while (*p) {
- if (*p == '"' || *p < 0x21 || *p > 0x7f) {
- audit_log_hex(ab, string, len);
- return string + len + 1;
- }
- p++;
- }
- audit_log_format(ab, "\"%s\"", 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.
+ */
+void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
+{
+ audit_log_n_untrustedstring(ab, string, strlen(string));
}
/* This is a helper-function to print the escaped d_path */
void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
- struct dentry *dentry, struct vfsmount *vfsmnt)
+ const struct path *path)
{
- char *p, *path;
+ char *p, *pathname;
if (prefix)
- audit_log_format(ab, " %s", prefix);
+ audit_log_format(ab, "%s", prefix);
/* We will allow 11 spaces for ' (deleted)' to be appended */
- path = kmalloc(PATH_MAX+11, ab->gfp_mask);
- if (!path) {
- audit_log_format(ab, "<no memory>");
+ pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
+ if (!pathname) {
+ audit_log_string(ab, "<no_memory>");
return;
}
- p = d_path(dentry, vfsmnt, path, PATH_MAX+11);
+ p = d_path(path, pathname, PATH_MAX+11);
if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
/* FIXME: can we save some information here? */
- audit_log_format(ab, "<too long>");
- } else
+ audit_log_string(ab, "<too_long>");
+ } else
audit_log_untrustedstring(ab, p);
- kfree(path);
+ kfree(pathname);
+}
+
+void audit_log_key(struct audit_buffer *ab, char *key)
+{
+ audit_log_format(ab, " key=");
+ if (key)
+ audit_log_untrustedstring(ab, key);
+ else
+ audit_log_format(ab, "(null)");
}
/**
if (!audit_rate_check()) {
audit_log_lost("rate limit exceeded");
} else {
+ struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
+ nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
+
if (audit_pid) {
- struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data;
- 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(KERN_NOTICE "%s\n", ab->skb->data + NLMSG_SPACE(0));
+ audit_printk_skb(ab->skb);
}
+ ab->skb = NULL;
}
audit_buffer_free(ab);
}
* 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,
+void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
const char *fmt, ...)
{
struct audit_buffer *ab;
}
}
+#ifdef CONFIG_SECURITY
+/**
+ * audit_log_secctx - Converts and logs SELinux context
+ * @ab: audit_buffer
+ * @secid: security number
+ *
+ * This is a helper function that calls security_secid_to_secctx to convert
+ * secid to secctx and then adds the (converted) SELinux context to the audit
+ * log by calling audit_log_format, thus also preventing leak of internal secid
+ * to userspace. If secid cannot be converted audit_panic is called.
+ */
+void audit_log_secctx(struct audit_buffer *ab, u32 secid)
+{
+ u32 len;
+ char *secctx;
+
+ if (security_secid_to_secctx(secid, &secctx, &len)) {
+ audit_panic("Cannot convert secid to context");
+ } else {
+ audit_log_format(ab, " obj=%s", secctx);
+ security_release_secctx(secctx, len);
+ }
+}
+EXPORT_SYMBOL(audit_log_secctx);
+#endif
+
EXPORT_SYMBOL(audit_log_start);
EXPORT_SYMBOL(audit_log_end);
EXPORT_SYMBOL(audit_log_format);
Code Review / linux-2.6.git / blobdiff