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-rw-r--r--kernel/audit.c2464
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diff --git a/kernel/audit.c b/kernel/audit.c
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+++ b/kernel/audit.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/* audit.c -- Auditing support
+ * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
+ * System-call specific features have moved to auditsc.c
+ *
+ * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
+ * All Rights Reserved.
+ *
+ * Written by Rickard E. (Rik) Faith <faith@redhat.com>
+ *
+ * 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
+ * is generated (defer as much work as possible to record
+ * generation time):
+ * i) context is allocated,
+ * ii) names from getname are stored without a copy, and
+ * iii) inode information stored from path_lookup.
+ * 3) Ability to disable syscall auditing at boot time (audit=0).
+ * 4) Usable by other parts of the kernel (if audit_log* is called,
+ * then a syscall record will be generated automatically for the
+ * current syscall).
+ * 5) Netlink interface to user-space.
+ * 6) Support low-overhead kernel-based filtering to minimize the
+ * information that must be passed to user-space.
+ *
+ * Audit userspace, documentation, tests, and bug/issue trackers:
+ * https://github.com/linux-audit
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/file.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/atomic.h>
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/kthread.h>
+#include <linux/kernel.h>
+#include <linux/syscalls.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/mutex.h>
+#include <linux/gfp.h>
+#include <linux/pid.h>
+
+#include <linux/audit.h>
+
+#include <net/sock.h>
+#include <net/netlink.h>
+#include <linux/skbuff.h>
+#ifdef CONFIG_SECURITY
+#include <linux/security.h>
+#endif
+#include <linux/freezer.h>
+#include <linux/pid_namespace.h>
+#include <net/netns/generic.h>
+
+#include "audit.h"
+
+/* 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 = AUDIT_UNINITIALIZED;
+
+u32 audit_enabled = AUDIT_OFF;
+bool audit_ever_enabled = !!AUDIT_OFF;
+
+EXPORT_SYMBOL_GPL(audit_enabled);
+
+/* Default state when kernel boots without any parameters. */
+static u32 audit_default = AUDIT_OFF;
+
+/* If auditing cannot proceed, audit_failure selects what happens. */
+static u32 audit_failure = AUDIT_FAIL_PRINTK;
+
+/* private audit network namespace index */
+static unsigned int audit_net_id;
+
+/**
+ * struct audit_net - audit private network namespace data
+ * @sk: communication socket
+ */
+struct audit_net {
+ struct sock *sk;
+};
+
+/**
+ * struct auditd_connection - kernel/auditd connection state
+ * @pid: auditd PID
+ * @portid: netlink portid
+ * @net: the associated network namespace
+ * @rcu: RCU head
+ *
+ * Description:
+ * This struct is RCU protected; you must either hold the RCU lock for reading
+ * or the associated spinlock for writing.
+ */
+struct auditd_connection {
+ struct pid *pid;
+ u32 portid;
+ struct net *net;
+ struct rcu_head rcu;
+};
+static struct auditd_connection __rcu *auditd_conn;
+static DEFINE_SPINLOCK(auditd_conn_lock);
+
+/* 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 u32 audit_rate_limit;
+
+/* Number of outstanding audit_buffers allowed.
+ * When set to zero, this means unlimited. */
+static u32 audit_backlog_limit = 64;
+#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
+static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
+
+/* The identity of the user shutting down the audit system. */
+static kuid_t audit_sig_uid = INVALID_UID;
+static pid_t audit_sig_pid = -1;
+static u32 audit_sig_sid;
+
+/* Records can be lost in several ways:
+ 0) [suppressed in audit_alloc]
+ 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
+ 2) out of memory in audit_log_move [alloc_skb]
+ 3) suppressed due to audit_rate_limit
+ 4) suppressed due to audit_backlog_limit
+*/
+static atomic_t audit_lost = ATOMIC_INIT(0);
+
+/* Monotonically increasing sum of time the kernel has spent
+ * waiting while the backlog limit is exceeded.
+ */
+static atomic_t audit_backlog_wait_time_actual = ATOMIC_INIT(0);
+
+/* Hash for inode-based rules */
+struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
+
+static struct kmem_cache *audit_buffer_cache;
+
+/* queue msgs to send via kauditd_task */
+static struct sk_buff_head audit_queue;
+/* queue msgs due to temporary unicast send problems */
+static struct sk_buff_head audit_retry_queue;
+/* queue msgs waiting for new auditd connection */
+static struct sk_buff_head audit_hold_queue;
+
+/* queue servicing thread */
+static struct task_struct *kauditd_task;
+static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
+
+/* waitqueue for callers who are blocked on the audit backlog */
+static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
+
+static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
+ .mask = -1,
+ .features = 0,
+ .lock = 0,};
+
+static char *audit_feature_names[2] = {
+ "only_unset_loginuid",
+ "loginuid_immutable",
+};
+
+/**
+ * struct audit_ctl_mutex - serialize requests from userspace
+ * @lock: the mutex used for locking
+ * @owner: the task which owns the lock
+ *
+ * Description:
+ * This is the lock struct used to ensure we only process userspace requests
+ * in an orderly fashion. We can't simply use a mutex/lock here because we
+ * need to track lock ownership so we don't end up blocking the lock owner in
+ * audit_log_start() or similar.
+ */
+static struct audit_ctl_mutex {
+ struct mutex lock;
+ void *owner;
+} 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
+ * should be at least that large. */
+#define AUDIT_BUFSIZ 1024
+
+/* The audit_buffer is used when formatting an audit record. The caller
+ * locks briefly to get the record off the freelist or to allocate the
+ * buffer, and locks briefly to send the buffer to the netlink layer or
+ * to place it on a transmit queue. Multiple audit_buffers can be in
+ * use simultaneously. */
+struct audit_buffer {
+ struct sk_buff *skb; /* formatted skb ready to send */
+ struct audit_context *ctx; /* NULL or associated context */
+ gfp_t gfp_mask;
+};
+
+struct audit_reply {
+ __u32 portid;
+ struct net *net;
+ struct sk_buff *skb;
+};
+
+/**
+ * auditd_test_task - Check to see if a given task is an audit daemon
+ * @task: the task to check
+ *
+ * Description:
+ * Return 1 if the task is a registered audit daemon, 0 otherwise.
+ */
+int auditd_test_task(struct task_struct *task)
+{
+ int rc;
+ struct auditd_connection *ac;
+
+ rcu_read_lock();
+ ac = rcu_dereference(auditd_conn);
+ rc = (ac && ac->pid == task_tgid(task) ? 1 : 0);
+ rcu_read_unlock();
+
+ return rc;
+}
+
+/**
+ * audit_ctl_lock - Take the audit control lock
+ */
+void audit_ctl_lock(void)
+{
+ mutex_lock(&audit_cmd_mutex.lock);
+ audit_cmd_mutex.owner = current;
+}
+
+/**
+ * audit_ctl_unlock - Drop the audit control lock
+ */
+void audit_ctl_unlock(void)
+{
+ audit_cmd_mutex.owner = NULL;
+ mutex_unlock(&audit_cmd_mutex.lock);
+}
+
+/**
+ * audit_ctl_owner_current - Test to see if the current task owns the lock
+ *
+ * Description:
+ * Return true if the current task owns the audit control lock, false if it
+ * doesn't own the lock.
+ */
+static bool audit_ctl_owner_current(void)
+{
+ return (current == audit_cmd_mutex.owner);
+}
+
+/**
+ * auditd_pid_vnr - Return the auditd PID relative to the namespace
+ *
+ * Description:
+ * Returns the PID in relation to the namespace, 0 on failure.
+ */
+static pid_t auditd_pid_vnr(void)
+{
+ pid_t pid;
+ const struct auditd_connection *ac;
+
+ rcu_read_lock();
+ ac = rcu_dereference(auditd_conn);
+ if (!ac || !ac->pid)
+ pid = 0;
+ else
+ pid = pid_vnr(ac->pid);
+ rcu_read_unlock();
+
+ return pid;
+}
+
+/**
+ * audit_get_sk - Return the audit socket for the given network namespace
+ * @net: the destination network namespace
+ *
+ * Description:
+ * Returns the sock pointer if valid, NULL otherwise. The caller must ensure
+ * that a reference is held for the network namespace while the sock is in use.
+ */
+static struct sock *audit_get_sk(const struct net *net)
+{
+ struct audit_net *aunet;
+
+ if (!net)
+ return NULL;
+
+ aunet = net_generic(net, audit_net_id);
+ return aunet->sk;
+}
+
+void audit_panic(const char *message)
+{
+ switch (audit_failure) {
+ case AUDIT_FAIL_SILENT:
+ break;
+ case AUDIT_FAIL_PRINTK:
+ if (printk_ratelimit())
+ pr_err("%s\n", message);
+ break;
+ case AUDIT_FAIL_PANIC:
+ panic("audit: %s\n", message);
+ break;
+ }
+}
+
+static inline int audit_rate_check(void)
+{
+ static unsigned long last_check = 0;
+ static int messages = 0;
+ static DEFINE_SPINLOCK(lock);
+ unsigned long flags;
+ unsigned long now;
+ int retval = 0;
+
+ if (!audit_rate_limit) return 1;
+
+ spin_lock_irqsave(&lock, flags);
+ if (++messages < audit_rate_limit) {
+ retval = 1;
+ } else {
+ now = jiffies;
+ if (time_after(now, last_check + HZ)) {
+ last_check = now;
+ messages = 0;
+ retval = 1;
+ }
+ }
+ spin_unlock_irqrestore(&lock, flags);
+
+ return retval;
+}
+
+/**
+ * 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;
+ static DEFINE_SPINLOCK(lock);
+ unsigned long flags;
+ unsigned long now;
+ int print;
+
+ atomic_inc(&audit_lost);
+
+ print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
+
+ if (!print) {
+ spin_lock_irqsave(&lock, flags);
+ now = jiffies;
+ if (time_after(now, last_msg + HZ)) {
+ print = 1;
+ last_msg = now;
+ }
+ spin_unlock_irqrestore(&lock, flags);
+ }
+
+ if (print) {
+ if (printk_ratelimit())
+ pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
+ atomic_read(&audit_lost),
+ audit_rate_limit,
+ audit_backlog_limit);
+ audit_panic(message);
+ }
+}
+
+static int audit_log_config_change(char *function_name, u32 new, u32 old,
+ int allow_changes)
+{
+ struct audit_buffer *ab;
+ int rc = 0;
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ if (unlikely(!ab))
+ return rc;
+ audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old);
+ audit_log_session_info(ab);
+ rc = audit_log_task_context(ab);
+ if (rc)
+ allow_changes = 0; /* Something weird, deny request */
+ audit_log_format(ab, " res=%d", allow_changes);
+ audit_log_end(ab);
+ return rc;
+}
+
+static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
+{
+ int allow_changes, rc = 0;
+ u32 old = *to_change;
+
+ /* 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, 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(u32 limit)
+{
+ return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
+}
+
+static int audit_set_backlog_limit(u32 limit)
+{
+ return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
+}
+
+static int audit_set_backlog_wait_time(u32 timeout)
+{
+ return audit_do_config_change("audit_backlog_wait_time",
+ &audit_backlog_wait_time, timeout);
+}
+
+static int audit_set_enabled(u32 state)
+{
+ int rc;
+ if (state > AUDIT_LOCKED)
+ return -EINVAL;
+
+ rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
+ if (!rc)
+ audit_ever_enabled |= !!state;
+
+ return rc;
+}
+
+static int audit_set_failure(u32 state)
+{
+ if (state != AUDIT_FAIL_SILENT
+ && state != AUDIT_FAIL_PRINTK
+ && state != AUDIT_FAIL_PANIC)
+ return -EINVAL;
+
+ return audit_do_config_change("audit_failure", &audit_failure, state);
+}
+
+/**
+ * auditd_conn_free - RCU helper to release an auditd connection struct
+ * @rcu: RCU head
+ *
+ * Description:
+ * Drop any references inside the auditd connection tracking struct and free
+ * the memory.
+ */
+static void auditd_conn_free(struct rcu_head *rcu)
+{
+ struct auditd_connection *ac;
+
+ ac = container_of(rcu, struct auditd_connection, rcu);
+ put_pid(ac->pid);
+ put_net(ac->net);
+ kfree(ac);
+}
+
+/**
+ * auditd_set - Set/Reset the auditd connection state
+ * @pid: auditd PID
+ * @portid: auditd netlink portid
+ * @net: auditd network namespace pointer
+ *
+ * Description:
+ * This function will obtain and drop network namespace references as
+ * necessary. Returns zero on success, negative values on failure.
+ */
+static int auditd_set(struct pid *pid, u32 portid, struct net *net)
+{
+ unsigned long flags;
+ struct auditd_connection *ac_old, *ac_new;
+
+ if (!pid || !net)
+ return -EINVAL;
+
+ ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL);
+ if (!ac_new)
+ return -ENOMEM;
+ ac_new->pid = get_pid(pid);
+ ac_new->portid = portid;
+ ac_new->net = get_net(net);
+
+ spin_lock_irqsave(&auditd_conn_lock, flags);
+ ac_old = rcu_dereference_protected(auditd_conn,
+ lockdep_is_held(&auditd_conn_lock));
+ rcu_assign_pointer(auditd_conn, ac_new);
+ spin_unlock_irqrestore(&auditd_conn_lock, flags);
+
+ if (ac_old)
+ call_rcu(&ac_old->rcu, auditd_conn_free);
+
+ return 0;
+}
+
+/**
+ * kauditd_printk_skb - Print the audit record to the ring buffer
+ * @skb: audit record
+ *
+ * Whatever the reason, this packet may not make it to the auditd connection
+ * so write it via printk so the information isn't completely lost.
+ */
+static void kauditd_printk_skb(struct sk_buff *skb)
+{
+ struct nlmsghdr *nlh = nlmsg_hdr(skb);
+ char *data = nlmsg_data(nlh);
+
+ if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit())
+ pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
+}
+
+/**
+ * kauditd_rehold_skb - Handle a audit record send failure in the hold queue
+ * @skb: audit record
+ * @error: error code (unused)
+ *
+ * Description:
+ * This should only be used by the kauditd_thread when it fails to flush the
+ * hold queue.
+ */
+static void kauditd_rehold_skb(struct sk_buff *skb, __always_unused int error)
+{
+ /* put the record back in the queue */
+ skb_queue_tail(&audit_hold_queue, skb);
+}
+
+/**
+ * kauditd_hold_skb - Queue an audit record, waiting for auditd
+ * @skb: audit record
+ * @error: error code
+ *
+ * Description:
+ * Queue the audit record, waiting for an instance of auditd. When this
+ * function is called we haven't given up yet on sending the record, but things
+ * are not looking good. The first thing we want to do is try to write the
+ * record via printk and then see if we want to try and hold on to the record
+ * and queue it, if we have room. If we want to hold on to the record, but we
+ * don't have room, record a record lost message.
+ */
+static void kauditd_hold_skb(struct sk_buff *skb, int error)
+{
+ /* at this point it is uncertain if we will ever send this to auditd so
+ * try to send the message via printk before we go any further */
+ kauditd_printk_skb(skb);
+
+ /* can we just silently drop the message? */
+ if (!audit_default)
+ goto drop;
+
+ /* the hold queue is only for when the daemon goes away completely,
+ * not -EAGAIN failures; if we are in a -EAGAIN state requeue the
+ * record on the retry queue unless it's full, in which case drop it
+ */
+ if (error == -EAGAIN) {
+ if (!audit_backlog_limit ||
+ skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
+ skb_queue_tail(&audit_retry_queue, skb);
+ return;
+ }
+ audit_log_lost("kauditd retry queue overflow");
+ goto drop;
+ }
+
+ /* if we have room in the hold queue, queue the message */
+ if (!audit_backlog_limit ||
+ skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
+ skb_queue_tail(&audit_hold_queue, skb);
+ return;
+ }
+
+ /* we have no other options - drop the message */
+ audit_log_lost("kauditd hold queue overflow");
+drop:
+ kfree_skb(skb);
+}
+
+/**
+ * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
+ * @skb: audit record
+ * @error: error code (unused)
+ *
+ * Description:
+ * Not as serious as kauditd_hold_skb() as we still have a connected auditd,
+ * but for some reason we are having problems sending it audit records so
+ * queue the given record and attempt to resend.
+ */
+static void kauditd_retry_skb(struct sk_buff *skb, __always_unused int error)
+{
+ if (!audit_backlog_limit ||
+ skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
+ skb_queue_tail(&audit_retry_queue, skb);
+ return;
+ }
+
+ /* we have to drop the record, send it via printk as a last effort */
+ kauditd_printk_skb(skb);
+ audit_log_lost("kauditd retry queue overflow");
+ kfree_skb(skb);
+}
+
+/**
+ * auditd_reset - Disconnect the auditd connection
+ * @ac: auditd connection state
+ *
+ * Description:
+ * Break the auditd/kauditd connection and move all the queued records into the
+ * hold queue in case auditd reconnects. It is important to note that the @ac
+ * pointer should never be dereferenced inside this function as it may be NULL
+ * or invalid, you can only compare the memory address! If @ac is NULL then
+ * the connection will always be reset.
+ */
+static void auditd_reset(const struct auditd_connection *ac)
+{
+ unsigned long flags;
+ struct sk_buff *skb;
+ struct auditd_connection *ac_old;
+
+ /* if it isn't already broken, break the connection */
+ spin_lock_irqsave(&auditd_conn_lock, flags);
+ ac_old = rcu_dereference_protected(auditd_conn,
+ lockdep_is_held(&auditd_conn_lock));
+ if (ac && ac != ac_old) {
+ /* someone already registered a new auditd connection */
+ spin_unlock_irqrestore(&auditd_conn_lock, flags);
+ return;
+ }
+ rcu_assign_pointer(auditd_conn, NULL);
+ spin_unlock_irqrestore(&auditd_conn_lock, flags);
+
+ if (ac_old)
+ call_rcu(&ac_old->rcu, auditd_conn_free);
+
+ /* flush the retry queue to the hold queue, but don't touch the main
+ * queue since we need to process that normally for multicast */
+ while ((skb = skb_dequeue(&audit_retry_queue)))
+ kauditd_hold_skb(skb, -ECONNREFUSED);
+}
+
+/**
+ * auditd_send_unicast_skb - Send a record via unicast to auditd
+ * @skb: audit record
+ *
+ * Description:
+ * Send a skb to the audit daemon, returns positive/zero values on success and
+ * negative values on failure; in all cases the skb will be consumed by this
+ * function. If the send results in -ECONNREFUSED the connection with auditd
+ * will be reset. This function may sleep so callers should not hold any locks
+ * where this would cause a problem.
+ */
+static int auditd_send_unicast_skb(struct sk_buff *skb)
+{
+ int rc;
+ u32 portid;
+ struct net *net;
+ struct sock *sk;
+ struct auditd_connection *ac;
+
+ /* NOTE: we can't call netlink_unicast while in the RCU section so
+ * take a reference to the network namespace and grab local
+ * copies of the namespace, the sock, and the portid; the
+ * namespace and sock aren't going to go away while we hold a
+ * reference and if the portid does become invalid after the RCU
+ * section netlink_unicast() should safely return an error */
+
+ rcu_read_lock();
+ ac = rcu_dereference(auditd_conn);
+ if (!ac) {
+ rcu_read_unlock();
+ kfree_skb(skb);
+ rc = -ECONNREFUSED;
+ goto err;
+ }
+ net = get_net(ac->net);
+ sk = audit_get_sk(net);
+ portid = ac->portid;
+ rcu_read_unlock();
+
+ rc = netlink_unicast(sk, skb, portid, 0);
+ put_net(net);
+ if (rc < 0)
+ goto err;
+
+ return rc;
+
+err:
+ if (ac && rc == -ECONNREFUSED)
+ auditd_reset(ac);
+ return rc;
+}
+
+/**
+ * kauditd_send_queue - Helper for kauditd_thread to flush skb queues
+ * @sk: the sending sock
+ * @portid: the netlink destination
+ * @queue: the skb queue to process
+ * @retry_limit: limit on number of netlink unicast failures
+ * @skb_hook: per-skb hook for additional processing
+ * @err_hook: hook called if the skb fails the netlink unicast send
+ *
+ * Description:
+ * Run through the given queue and attempt to send the audit records to auditd,
+ * returns zero on success, negative values on failure. It is up to the caller
+ * to ensure that the @sk is valid for the duration of this function.
+ *
+ */
+static int kauditd_send_queue(struct sock *sk, u32 portid,
+ struct sk_buff_head *queue,
+ unsigned int retry_limit,
+ void (*skb_hook)(struct sk_buff *skb),
+ void (*err_hook)(struct sk_buff *skb, int error))
+{
+ int rc = 0;
+ struct sk_buff *skb = NULL;
+ struct sk_buff *skb_tail;
+ unsigned int failed = 0;
+
+ /* NOTE: kauditd_thread takes care of all our locking, we just use
+ * the netlink info passed to us (e.g. sk and portid) */
+
+ skb_tail = skb_peek_tail(queue);
+ while ((skb != skb_tail) && (skb = skb_dequeue(queue))) {
+ /* call the skb_hook for each skb we touch */
+ if (skb_hook)
+ (*skb_hook)(skb);
+
+ /* can we send to anyone via unicast? */
+ if (!sk) {
+ if (err_hook)
+ (*err_hook)(skb, -ECONNREFUSED);
+ continue;
+ }
+
+retry:
+ /* grab an extra skb reference in case of error */
+ skb_get(skb);
+ rc = netlink_unicast(sk, skb, portid, 0);
+ if (rc < 0) {
+ /* send failed - try a few times unless fatal error */
+ if (++failed >= retry_limit ||
+ rc == -ECONNREFUSED || rc == -EPERM) {
+ sk = NULL;
+ if (err_hook)
+ (*err_hook)(skb, rc);
+ if (rc == -EAGAIN)
+ rc = 0;
+ /* continue to drain the queue */
+ continue;
+ } else
+ goto retry;
+ } else {
+ /* skb sent - drop the extra reference and continue */
+ consume_skb(skb);
+ failed = 0;
+ }
+ }
+
+ return (rc >= 0 ? 0 : rc);
+}
+
+/*
+ * kauditd_send_multicast_skb - Send a record to any multicast listeners
+ * @skb: audit record
+ *
+ * Description:
+ * Write a multicast message to anyone listening in the initial network
+ * namespace. This function doesn't consume an skb as might be expected since
+ * it has to copy it anyways.
+ */
+static void kauditd_send_multicast_skb(struct sk_buff *skb)
+{
+ struct sk_buff *copy;
+ struct sock *sock = audit_get_sk(&init_net);
+ struct nlmsghdr *nlh;
+
+ /* NOTE: we are not taking an additional reference for init_net since
+ * we don't have to worry about it going away */
+
+ if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
+ return;
+
+ /*
+ * The seemingly wasteful skb_copy() rather than bumping the refcount
+ * using skb_get() is necessary because non-standard mods are made to
+ * the skb by the original kaudit unicast socket send routine. The
+ * existing auditd daemon assumes this breakage. Fixing this would
+ * require co-ordinating a change in the established protocol between
+ * the kaudit kernel subsystem and the auditd userspace code. There is
+ * no reason for new multicast clients to continue with this
+ * non-compliance.
+ */
+ copy = skb_copy(skb, GFP_KERNEL);
+ if (!copy)
+ return;
+ nlh = nlmsg_hdr(copy);
+ nlh->nlmsg_len = skb->len;
+
+ nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
+}
+
+/**
+ * kauditd_thread - Worker thread to send audit records to userspace
+ * @dummy: unused
+ */
+static int kauditd_thread(void *dummy)
+{
+ int rc;
+ u32 portid = 0;
+ struct net *net = NULL;
+ struct sock *sk = NULL;
+ struct auditd_connection *ac;
+
+#define UNICAST_RETRIES 5
+
+ set_freezable();
+ while (!kthread_should_stop()) {
+ /* NOTE: see the lock comments in auditd_send_unicast_skb() */
+ rcu_read_lock();
+ ac = rcu_dereference(auditd_conn);
+ if (!ac) {
+ rcu_read_unlock();
+ goto main_queue;
+ }
+ net = get_net(ac->net);
+ sk = audit_get_sk(net);
+ portid = ac->portid;
+ rcu_read_unlock();
+
+ /* attempt to flush the hold queue */
+ rc = kauditd_send_queue(sk, portid,
+ &audit_hold_queue, UNICAST_RETRIES,
+ NULL, kauditd_rehold_skb);
+ if (rc < 0) {
+ sk = NULL;
+ auditd_reset(ac);
+ goto main_queue;
+ }
+
+ /* attempt to flush the retry queue */
+ rc = kauditd_send_queue(sk, portid,
+ &audit_retry_queue, UNICAST_RETRIES,
+ NULL, kauditd_hold_skb);
+ if (rc < 0) {
+ sk = NULL;
+ auditd_reset(ac);
+ goto main_queue;
+ }
+
+main_queue:
+ /* process the main queue - do the multicast send and attempt
+ * unicast, dump failed record sends to the retry queue; if
+ * sk == NULL due to previous failures we will just do the
+ * multicast send and move the record to the hold queue */
+ rc = kauditd_send_queue(sk, portid, &audit_queue, 1,
+ kauditd_send_multicast_skb,
+ (sk ?
+ kauditd_retry_skb : kauditd_hold_skb));
+ if (ac && rc < 0)
+ auditd_reset(ac);
+ sk = NULL;
+
+ /* drop our netns reference, no auditd sends past this line */
+ if (net) {
+ put_net(net);
+ net = NULL;
+ }
+
+ /* we have processed all the queues so wake everyone */
+ wake_up(&audit_backlog_wait);
+
+ /* NOTE: we want to wake up if there is anything on the queue,
+ * regardless of if an auditd is connected, as we need to
+ * do the multicast send and rotate records from the
+ * main queue to the retry/hold queues */
+ wait_event_freezable(kauditd_wait,
+ (skb_queue_len(&audit_queue) ? 1 : 0));
+ }
+
+ return 0;
+}
+
+int audit_send_list_thread(void *_dest)
+{
+ struct audit_netlink_list *dest = _dest;
+ struct sk_buff *skb;
+ struct sock *sk = audit_get_sk(dest->net);
+
+ /* wait for parent to finish and send an ACK */
+ audit_ctl_lock();
+ audit_ctl_unlock();
+
+ while ((skb = __skb_dequeue(&dest->q)) != NULL)
+ netlink_unicast(sk, skb, dest->portid, 0);
+
+ put_net(dest->net);
+ kfree(dest);
+
+ return 0;
+}
+
+struct sk_buff *audit_make_reply(int seq, int type, int done,
+ int multi, const void *payload, int size)
+{
+ struct sk_buff *skb;
+ struct nlmsghdr *nlh;
+ void *data;
+ int flags = multi ? NLM_F_MULTI : 0;
+ int t = done ? NLMSG_DONE : type;
+
+ skb = nlmsg_new(size, GFP_KERNEL);
+ if (!skb)
+ return NULL;
+
+ nlh = nlmsg_put(skb, 0, seq, t, size, flags);
+ if (!nlh)
+ goto out_kfree_skb;
+ data = nlmsg_data(nlh);
+ memcpy(data, payload, size);
+ return skb;
+
+out_kfree_skb:
+ kfree_skb(skb);
+ return NULL;
+}
+
+static void audit_free_reply(struct audit_reply *reply)
+{
+ if (!reply)
+ return;
+
+ kfree_skb(reply->skb);
+ if (reply->net)
+ put_net(reply->net);
+ kfree(reply);
+}
+
+static int audit_send_reply_thread(void *arg)
+{
+ struct audit_reply *reply = (struct audit_reply *)arg;
+
+ audit_ctl_lock();
+ audit_ctl_unlock();
+
+ /* Ignore failure. It'll only happen if the sender goes away,
+ because our timeout is set to infinite. */
+ netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0);
+ reply->skb = NULL;
+ audit_free_reply(reply);
+ return 0;
+}
+
+/**
+ * audit_send_reply - send an audit reply message via netlink
+ * @request_skb: skb of request we are replying to (used to target the reply)
+ * @seq: sequence number
+ * @type: audit message type
+ * @done: done (last) flag
+ * @multi: multi-part message flag
+ * @payload: payload data
+ * @size: payload size
+ *
+ * Allocates a skb, builds the netlink message, and sends it to the port id.
+ */
+static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
+ int multi, const void *payload, int size)
+{
+ struct task_struct *tsk;
+ struct audit_reply *reply;
+
+ reply = kzalloc(sizeof(*reply), GFP_KERNEL);
+ if (!reply)
+ return;
+
+ reply->skb = audit_make_reply(seq, type, done, multi, payload, size);
+ if (!reply->skb)
+ goto err;
+ reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
+ reply->portid = NETLINK_CB(request_skb).portid;
+
+ tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
+ if (IS_ERR(tsk))
+ goto err;
+
+ return;
+
+err:
+ audit_free_reply(reply);
+}
+
+/*
+ * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
+ * control messages.
+ */
+static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
+{
+ int err = 0;
+
+ /* Only support initial user namespace for now. */
+ /*
+ * We return ECONNREFUSED because it tricks userspace into thinking
+ * that audit was not configured into the kernel. Lots of users
+ * configure their PAM stack (because that's what the distro does)
+ * to reject login if unable to send messages to audit. If we return
+ * ECONNREFUSED the PAM stack thinks the kernel does not have audit
+ * configured in and will let login proceed. If we return EPERM
+ * userspace will reject all logins. This should be removed when we
+ * support non init namespaces!!
+ */
+ if (current_user_ns() != &init_user_ns)
+ return -ECONNREFUSED;
+
+ switch (msg_type) {
+ case AUDIT_LIST:
+ case AUDIT_ADD:
+ case AUDIT_DEL:
+ return -EOPNOTSUPP;
+ case AUDIT_GET:
+ case AUDIT_SET:
+ case AUDIT_GET_FEATURE:
+ case AUDIT_SET_FEATURE:
+ case AUDIT_LIST_RULES:
+ case AUDIT_ADD_RULE:
+ case AUDIT_DEL_RULE:
+ case AUDIT_SIGNAL_INFO:
+ case AUDIT_TTY_GET:
+ case AUDIT_TTY_SET:
+ case AUDIT_TRIM:
+ case AUDIT_MAKE_EQUIV:
+ /* Only support auditd and auditctl in initial pid namespace
+ * for now. */
+ if (task_active_pid_ns(current) != &init_pid_ns)
+ return -EPERM;
+
+ if (!netlink_capable(skb, 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 (!netlink_capable(skb, CAP_AUDIT_WRITE))
+ err = -EPERM;
+ break;
+ default: /* bad msg */
+ err = -EINVAL;
+ }
+
+ return err;
+}
+
+static void audit_log_common_recv_msg(struct audit_context *context,
+ struct audit_buffer **ab, u16 msg_type)
+{
+ uid_t uid = from_kuid(&init_user_ns, current_uid());
+ pid_t pid = task_tgid_nr(current);
+
+ if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
+ *ab = NULL;
+ return;
+ }
+
+ *ab = audit_log_start(context, GFP_KERNEL, msg_type);
+ if (unlikely(!*ab))
+ return;
+ audit_log_format(*ab, "pid=%d uid=%u ", pid, uid);
+ audit_log_session_info(*ab);
+ audit_log_task_context(*ab);
+}
+
+static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
+ u16 msg_type)
+{
+ audit_log_common_recv_msg(NULL, ab, msg_type);
+}
+
+static int is_audit_feature_set(int i)
+{
+ return af.features & AUDIT_FEATURE_TO_MASK(i);
+}
+
+
+static int audit_get_feature(struct sk_buff *skb)
+{
+ u32 seq;
+
+ seq = nlmsg_hdr(skb)->nlmsg_seq;
+
+ audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
+
+ return 0;
+}
+
+static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
+ u32 old_lock, u32 new_lock, int res)
+{
+ struct audit_buffer *ab;
+
+ if (audit_enabled == AUDIT_OFF)
+ return;
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_FEATURE_CHANGE);
+ if (!ab)
+ return;
+ audit_log_task_info(ab);
+ audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
+ audit_feature_names[which], !!old_feature, !!new_feature,
+ !!old_lock, !!new_lock, res);
+ audit_log_end(ab);
+}
+
+static int audit_set_feature(struct audit_features *uaf)
+{
+ int i;
+
+ BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
+
+ /* if there is ever a version 2 we should handle that here */
+
+ for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
+ u32 feature = AUDIT_FEATURE_TO_MASK(i);
+ u32 old_feature, new_feature, old_lock, new_lock;
+
+ /* if we are not changing this feature, move along */
+ if (!(feature & uaf->mask))
+ continue;
+
+ old_feature = af.features & feature;
+ new_feature = uaf->features & feature;
+ new_lock = (uaf->lock | af.lock) & feature;
+ old_lock = af.lock & feature;
+
+ /* are we changing a locked feature? */
+ if (old_lock && (new_feature != old_feature)) {
+ audit_log_feature_change(i, old_feature, new_feature,
+ old_lock, new_lock, 0);
+ return -EPERM;
+ }
+ }
+ /* nothing invalid, do the changes */
+ for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
+ u32 feature = AUDIT_FEATURE_TO_MASK(i);
+ u32 old_feature, new_feature, old_lock, new_lock;
+
+ /* if we are not changing this feature, move along */
+ if (!(feature & uaf->mask))
+ continue;
+
+ old_feature = af.features & feature;
+ new_feature = uaf->features & feature;
+ old_lock = af.lock & feature;
+ new_lock = (uaf->lock | af.lock) & feature;
+
+ if (new_feature != old_feature)
+ audit_log_feature_change(i, old_feature, new_feature,
+ old_lock, new_lock, 1);
+
+ if (new_feature)
+ af.features |= feature;
+ else
+ af.features &= ~feature;
+ af.lock |= new_lock;
+ }
+
+ return 0;
+}
+
+static int audit_replace(struct pid *pid)
+{
+ pid_t pvnr;
+ struct sk_buff *skb;
+
+ pvnr = pid_vnr(pid);
+ skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr));
+ if (!skb)
+ return -ENOMEM;
+ return auditd_send_unicast_skb(skb);
+}
+
+static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ u32 seq;
+ void *data;
+ int data_len;
+ int err;
+ struct audit_buffer *ab;
+ u16 msg_type = nlh->nlmsg_type;
+ struct audit_sig_info *sig_data;
+ char *ctx = NULL;
+ u32 len;
+
+ err = audit_netlink_ok(skb, msg_type);
+ if (err)
+ return err;
+
+ seq = nlh->nlmsg_seq;
+ data = nlmsg_data(nlh);
+ data_len = nlmsg_len(nlh);
+
+ switch (msg_type) {
+ case AUDIT_GET: {
+ struct audit_status s;
+ memset(&s, 0, sizeof(s));
+ s.enabled = audit_enabled;
+ s.failure = audit_failure;
+ /* NOTE: use pid_vnr() so the PID is relative to the current
+ * namespace */
+ s.pid = auditd_pid_vnr();
+ s.rate_limit = audit_rate_limit;
+ s.backlog_limit = audit_backlog_limit;
+ s.lost = atomic_read(&audit_lost);
+ s.backlog = skb_queue_len(&audit_queue);
+ s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
+ s.backlog_wait_time = audit_backlog_wait_time;
+ s.backlog_wait_time_actual = atomic_read(&audit_backlog_wait_time_actual);
+ audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
+ break;
+ }
+ case AUDIT_SET: {
+ struct audit_status s;
+ memset(&s, 0, sizeof(s));
+ /* guard against past and future API changes */
+ memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
+ if (s.mask & AUDIT_STATUS_ENABLED) {
+ err = audit_set_enabled(s.enabled);
+ if (err < 0)
+ return err;
+ }
+ if (s.mask & AUDIT_STATUS_FAILURE) {
+ err = audit_set_failure(s.failure);
+ if (err < 0)
+ return err;
+ }
+ if (s.mask & AUDIT_STATUS_PID) {
+ /* NOTE: we are using the vnr PID functions below
+ * because the s.pid value is relative to the
+ * namespace of the caller; at present this
+ * doesn't matter much since you can really only
+ * run auditd from the initial pid namespace, but
+ * something to keep in mind if this changes */
+ pid_t new_pid = s.pid;
+ pid_t auditd_pid;
+ struct pid *req_pid = task_tgid(current);
+
+ /* Sanity check - PID values must match. Setting
+ * pid to 0 is how auditd ends auditing. */
+ if (new_pid && (new_pid != pid_vnr(req_pid)))
+ return -EINVAL;
+
+ /* test the auditd connection */
+ audit_replace(req_pid);
+
+ auditd_pid = auditd_pid_vnr();
+ if (auditd_pid) {
+ /* replacing a healthy auditd is not allowed */
+ if (new_pid) {
+ audit_log_config_change("audit_pid",
+ new_pid, auditd_pid, 0);
+ return -EEXIST;
+ }
+ /* only current auditd can unregister itself */
+ if (pid_vnr(req_pid) != auditd_pid) {
+ audit_log_config_change("audit_pid",
+ new_pid, auditd_pid, 0);
+ return -EACCES;
+ }
+ }
+
+ if (new_pid) {
+ /* register a new auditd connection */
+ err = auditd_set(req_pid,
+ NETLINK_CB(skb).portid,
+ sock_net(NETLINK_CB(skb).sk));
+ if (audit_enabled != AUDIT_OFF)
+ audit_log_config_change("audit_pid",
+ new_pid,
+ auditd_pid,
+ err ? 0 : 1);
+ if (err)
+ return err;
+
+ /* try to process any backlog */
+ wake_up_interruptible(&kauditd_wait);
+ } else {
+ if (audit_enabled != AUDIT_OFF)
+ audit_log_config_change("audit_pid",
+ new_pid,
+ auditd_pid, 1);
+
+ /* unregister the auditd connection */
+ auditd_reset(NULL);
+ }
+ }
+ if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
+ err = audit_set_rate_limit(s.rate_limit);
+ if (err < 0)
+ return err;
+ }
+ if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
+ err = audit_set_backlog_limit(s.backlog_limit);
+ if (err < 0)
+ return err;
+ }
+ if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
+ if (sizeof(s) > (size_t)nlh->nlmsg_len)
+ return -EINVAL;
+ if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
+ return -EINVAL;
+ err = audit_set_backlog_wait_time(s.backlog_wait_time);
+ if (err < 0)
+ return err;
+ }
+ if (s.mask == AUDIT_STATUS_LOST) {
+ u32 lost = atomic_xchg(&audit_lost, 0);
+
+ audit_log_config_change("lost", 0, lost, 1);
+ return lost;
+ }
+ if (s.mask == AUDIT_STATUS_BACKLOG_WAIT_TIME_ACTUAL) {
+ u32 actual = atomic_xchg(&audit_backlog_wait_time_actual, 0);
+
+ audit_log_config_change("backlog_wait_time_actual", 0, actual, 1);
+ return actual;
+ }
+ break;
+ }
+ case AUDIT_GET_FEATURE:
+ err = audit_get_feature(skb);
+ if (err)
+ return err;
+ break;
+ case AUDIT_SET_FEATURE:
+ if (data_len < sizeof(struct audit_features))
+ return -EINVAL;
+ err = audit_set_feature(data);
+ if (err)
+ return err;
+ 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;
+ /* exit early if there isn't at least one character to print */
+ if (data_len < 2)
+ return -EINVAL;
+
+ err = audit_filter(msg_type, AUDIT_FILTER_USER);
+ if (err == 1) { /* match or error */
+ char *str = data;
+
+ err = 0;
+ if (msg_type == AUDIT_USER_TTY) {
+ err = tty_audit_push();
+ if (err)
+ break;
+ }
+ audit_log_user_recv_msg(&ab, msg_type);
+ if (msg_type != AUDIT_USER_TTY) {
+ /* ensure NULL termination */
+ str[data_len - 1] = '\0';
+ audit_log_format(ab, " msg='%.*s'",
+ AUDIT_MESSAGE_TEXT_MAX,
+ str);
+ } else {
+ audit_log_format(ab, " data=");
+ if (str[data_len - 1] == '\0')
+ data_len--;
+ audit_log_n_untrustedstring(ab, str, data_len);
+ }
+ audit_log_end(ab);
+ }
+ break;
+ case AUDIT_ADD_RULE:
+ case AUDIT_DEL_RULE:
+ if (data_len < sizeof(struct audit_rule_data))
+ return -EINVAL;
+ if (audit_enabled == AUDIT_LOCKED) {
+ audit_log_common_recv_msg(audit_context(), &ab,
+ AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, " op=%s audit_enabled=%d res=0",
+ msg_type == AUDIT_ADD_RULE ?
+ "add_rule" : "remove_rule",
+ audit_enabled);
+ audit_log_end(ab);
+ return -EPERM;
+ }
+ err = audit_rule_change(msg_type, seq, data, data_len);
+ break;
+ case AUDIT_LIST_RULES:
+ err = audit_list_rules_send(skb, seq);
+ break;
+ case AUDIT_TRIM:
+ audit_trim_trees();
+ audit_log_common_recv_msg(audit_context(), &ab,
+ AUDIT_CONFIG_CHANGE);
+ 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 = data_len;
+ 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(audit_context(), &ab,
+ AUDIT_CONFIG_CHANGE);
+ 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:
+ len = 0;
+ if (audit_sig_sid) {
+ err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
+ if (err)
+ return err;
+ }
+ sig_data = kmalloc(struct_size(sig_data, ctx, len), GFP_KERNEL);
+ if (!sig_data) {
+ if (audit_sig_sid)
+ security_release_secctx(ctx, len);
+ return -ENOMEM;
+ }
+ sig_data->uid = from_kuid(&init_user_ns, 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(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
+ sig_data, struct_size(sig_data, ctx, len));
+ kfree(sig_data);
+ break;
+ case AUDIT_TTY_GET: {
+ struct audit_tty_status s;
+ unsigned int t;
+
+ t = READ_ONCE(current->signal->audit_tty);
+ s.enabled = t & AUDIT_TTY_ENABLE;
+ s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
+
+ audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
+ break;
+ }
+ case AUDIT_TTY_SET: {
+ struct audit_tty_status s, old;
+ struct audit_buffer *ab;
+ unsigned int t;
+
+ memset(&s, 0, sizeof(s));
+ /* guard against past and future API changes */
+ memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
+ /* check if new data is valid */
+ if ((s.enabled != 0 && s.enabled != 1) ||
+ (s.log_passwd != 0 && s.log_passwd != 1))
+ err = -EINVAL;
+
+ if (err)
+ t = READ_ONCE(current->signal->audit_tty);
+ else {
+ t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
+ t = xchg(&current->signal->audit_tty, t);
+ }
+ old.enabled = t & AUDIT_TTY_ENABLE;
+ old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
+
+ audit_log_common_recv_msg(audit_context(), &ab,
+ AUDIT_CONFIG_CHANGE);
+ audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
+ " old-log_passwd=%d new-log_passwd=%d res=%d",
+ old.enabled, s.enabled, old.log_passwd,
+ s.log_passwd, !err);
+ audit_log_end(ab);
+ break;
+ }
+ default:
+ err = -EINVAL;
+ break;
+ }
+
+ return err < 0 ? err : 0;
+}
+
+/**
+ * audit_receive - receive messages from a netlink control socket
+ * @skb: the message buffer
+ *
+ * Parse the provided skb and deal with any messages that may be present,
+ * malformed skbs are discarded.
+ */
+static void audit_receive(struct sk_buff *skb)
+{
+ 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;
+
+ audit_ctl_lock();
+ 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, NULL);
+
+ nlh = nlmsg_next(nlh, &len);
+ }
+ audit_ctl_unlock();
+
+ /* can't block with the ctrl lock, so penalize the sender now */
+ if (audit_backlog_limit &&
+ (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
+ DECLARE_WAITQUEUE(wait, current);
+
+ /* wake kauditd to try and flush the queue */
+ wake_up_interruptible(&kauditd_wait);
+
+ add_wait_queue_exclusive(&audit_backlog_wait, &wait);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ schedule_timeout(audit_backlog_wait_time);
+ remove_wait_queue(&audit_backlog_wait, &wait);
+ }
+}
+
+/* Log information about who is connecting to the audit multicast socket */
+static void audit_log_multicast(int group, const char *op, int err)
+{
+ const struct cred *cred;
+ struct tty_struct *tty;
+ char comm[sizeof(current->comm)];
+ struct audit_buffer *ab;
+
+ if (!audit_enabled)
+ return;
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
+ if (!ab)
+ return;
+
+ cred = current_cred();
+ tty = audit_get_tty();
+ audit_log_format(ab, "pid=%u uid=%u auid=%u tty=%s ses=%u",
+ task_pid_nr(current),
+ from_kuid(&init_user_ns, cred->uid),
+ from_kuid(&init_user_ns, audit_get_loginuid(current)),
+ tty ? tty_name(tty) : "(none)",
+ audit_get_sessionid(current));
+ audit_put_tty(tty);
+ audit_log_task_context(ab); /* subj= */
+ audit_log_format(ab, " comm=");
+ audit_log_untrustedstring(ab, get_task_comm(comm, current));
+ audit_log_d_path_exe(ab, current->mm); /* exe= */
+ audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
+ audit_log_end(ab);
+}
+
+/* Run custom bind function on netlink socket group connect or bind requests. */
+static int audit_multicast_bind(struct net *net, int group)
+{
+ int err = 0;
+
+ if (!capable(CAP_AUDIT_READ))
+ err = -EPERM;
+ audit_log_multicast(group, "connect", err);
+ return err;
+}
+
+static void audit_multicast_unbind(struct net *net, int group)
+{
+ audit_log_multicast(group, "disconnect", 0);
+}
+
+static int __net_init audit_net_init(struct net *net)
+{
+ struct netlink_kernel_cfg cfg = {
+ .input = audit_receive,
+ .bind = audit_multicast_bind,
+ .unbind = audit_multicast_unbind,
+ .flags = NL_CFG_F_NONROOT_RECV,
+ .groups = AUDIT_NLGRP_MAX,
+ };
+
+ struct audit_net *aunet = net_generic(net, audit_net_id);
+
+ aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
+ if (aunet->sk == NULL) {
+ audit_panic("cannot initialize netlink socket in namespace");
+ return -ENOMEM;
+ }
+ /* limit the timeout in case auditd is blocked/stopped */
+ aunet->sk->sk_sndtimeo = HZ / 10;
+
+ return 0;
+}
+
+static void __net_exit audit_net_exit(struct net *net)
+{
+ struct audit_net *aunet = net_generic(net, audit_net_id);
+
+ /* NOTE: you would think that we would want to check the auditd
+ * connection and potentially reset it here if it lives in this
+ * namespace, but since the auditd connection tracking struct holds a
+ * reference to this namespace (see auditd_set()) we are only ever
+ * going to get here after that connection has been released */
+
+ netlink_kernel_release(aunet->sk);
+}
+
+static struct pernet_operations audit_net_ops __net_initdata = {
+ .init = audit_net_init,
+ .exit = audit_net_exit,
+ .id = &audit_net_id,
+ .size = sizeof(struct audit_net),
+};
+
+/* Initialize audit support at boot time. */
+static int __init audit_init(void)
+{
+ int i;
+
+ if (audit_initialized == AUDIT_DISABLED)
+ return 0;
+
+ audit_buffer_cache = kmem_cache_create("audit_buffer",
+ sizeof(struct audit_buffer),
+ 0, SLAB_PANIC, NULL);
+
+ skb_queue_head_init(&audit_queue);
+ skb_queue_head_init(&audit_retry_queue);
+ skb_queue_head_init(&audit_hold_queue);
+
+ for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
+ INIT_LIST_HEAD(&audit_inode_hash[i]);
+
+ mutex_init(&audit_cmd_mutex.lock);
+ audit_cmd_mutex.owner = NULL;
+
+ pr_info("initializing netlink subsys (%s)\n",
+ audit_default ? "enabled" : "disabled");
+ register_pernet_subsys(&audit_net_ops);
+
+ audit_initialized = AUDIT_INITIALIZED;
+
+ kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
+ if (IS_ERR(kauditd_task)) {
+ int err = PTR_ERR(kauditd_task);
+ panic("audit: failed to start the kauditd thread (%d)\n", err);
+ }
+
+ audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL,
+ "state=initialized audit_enabled=%u res=1",
+ audit_enabled);
+
+ return 0;
+}
+postcore_initcall(audit_init);
+
+/*
+ * Process kernel command-line parameter at boot time.
+ * audit={0|off} or audit={1|on}.
+ */
+static int __init audit_enable(char *str)
+{
+ if (!strcasecmp(str, "off") || !strcmp(str, "0"))
+ audit_default = AUDIT_OFF;
+ else if (!strcasecmp(str, "on") || !strcmp(str, "1"))
+ audit_default = AUDIT_ON;
+ else {
+ pr_err("audit: invalid 'audit' parameter value (%s)\n", str);
+ audit_default = AUDIT_ON;
+ }
+
+ if (audit_default == AUDIT_OFF)
+ audit_initialized = AUDIT_DISABLED;
+ if (audit_set_enabled(audit_default))
+ pr_err("audit: error setting audit state (%d)\n",
+ audit_default);
+
+ pr_info("%s\n", audit_default ?
+ "enabled (after initialization)" : "disabled (until reboot)");
+
+ return 1;
+}
+__setup("audit=", audit_enable);
+
+/* Process kernel command-line parameter at boot time.
+ * audit_backlog_limit=<n> */
+static int __init audit_backlog_limit_set(char *str)
+{
+ u32 audit_backlog_limit_arg;
+
+ pr_info("audit_backlog_limit: ");
+ if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
+ pr_cont("using default of %u, unable to parse %s\n",
+ audit_backlog_limit, str);
+ return 1;
+ }
+
+ audit_backlog_limit = audit_backlog_limit_arg;
+ pr_cont("%d\n", audit_backlog_limit);
+
+ return 1;
+}
+__setup("audit_backlog_limit=", audit_backlog_limit_set);
+
+static void audit_buffer_free(struct audit_buffer *ab)
+{
+ if (!ab)
+ return;
+
+ kfree_skb(ab->skb);
+ kmem_cache_free(audit_buffer_cache, ab);
+}
+
+static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
+ gfp_t gfp_mask, int type)
+{
+ struct audit_buffer *ab;
+
+ ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask);
+ if (!ab)
+ return NULL;
+
+ ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
+ if (!ab->skb)
+ goto err;
+ if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
+ goto err;
+
+ ab->ctx = ctx;
+ ab->gfp_mask = gfp_mask;
+
+ return ab;
+
+err:
+ audit_buffer_free(ab);
+ return NULL;
+}
+
+/**
+ * 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
+ * determine which pieces belong to the same audit record. The
+ * (timestamp,serial) tuple is unique for each syscall and is live from
+ * syscall entry to syscall exit.
+ *
+ * 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).
+ */
+unsigned int audit_serial(void)
+{
+ static atomic_t serial = ATOMIC_INIT(0);
+
+ return atomic_inc_return(&serial);
+}
+
+static inline void audit_get_stamp(struct audit_context *ctx,
+ struct timespec64 *t, unsigned int *serial)
+{
+ if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
+ ktime_get_coarse_real_ts64(t);
+ *serial = audit_serial();
+ }
+}
+
+/**
+ * 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;
+ struct timespec64 t;
+ unsigned int serial;
+
+ if (audit_initialized != AUDIT_INITIALIZED)
+ return NULL;
+
+ if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCLUDE)))
+ return NULL;
+
+ /* NOTE: don't ever fail/sleep on these two conditions:
+ * 1. auditd generated record - since we need auditd to drain the
+ * queue; also, when we are checking for auditd, compare PIDs using
+ * task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
+ * using a PID anchored in the caller's namespace
+ * 2. generator holding the audit_cmd_mutex - we don't want to block
+ * while holding the mutex, although we do penalize the sender
+ * later in audit_receive() when it is safe to block
+ */
+ if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
+ long stime = audit_backlog_wait_time;
+
+ while (audit_backlog_limit &&
+ (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
+ /* wake kauditd to try and flush the queue */
+ wake_up_interruptible(&kauditd_wait);
+
+ /* sleep if we are allowed and we haven't exhausted our
+ * backlog wait limit */
+ if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
+ long rtime = stime;
+
+ DECLARE_WAITQUEUE(wait, current);
+
+ add_wait_queue_exclusive(&audit_backlog_wait,
+ &wait);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ stime = schedule_timeout(rtime);
+ atomic_add(rtime - stime, &audit_backlog_wait_time_actual);
+ remove_wait_queue(&audit_backlog_wait, &wait);
+ } else {
+ if (audit_rate_check() && printk_ratelimit())
+ pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
+ skb_queue_len(&audit_queue),
+ audit_backlog_limit);
+ audit_log_lost("backlog limit exceeded");
+ return NULL;
+ }
+ }
+ }
+
+ ab = audit_buffer_alloc(ctx, gfp_mask, type);
+ if (!ab) {
+ audit_log_lost("out of memory in audit_log_start");
+ return NULL;
+ }
+
+ audit_get_stamp(ab->ctx, &t, &serial);
+ /* cancel dummy context to enable supporting records */
+ if (ctx)
+ ctx->dummy = 0;
+ audit_log_format(ab, "audit(%llu.%03lu:%u): ",
+ (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
+
+ return ab;
+}
+
+/**
+ * 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.
+ */
+static inline int audit_expand(struct audit_buffer *ab, int extra)
+{
+ struct sk_buff *skb = ab->skb;
+ 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;
+ }
+
+ skb->truesize += newtail - oldtail;
+ return newtail;
+}
+
+/*
+ * 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.
+ */
+static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
+ va_list args)
+{
+ int len, avail;
+ struct sk_buff *skb;
+ va_list args2;
+
+ if (!ab)
+ return;
+
+ BUG_ON(!ab->skb);
+ skb = ab->skb;
+ avail = skb_tailroom(skb);
+ if (avail == 0) {
+ avail = audit_expand(ab, AUDIT_BUFSIZ);
+ if (!avail)
+ goto out;
+ }
+ va_copy(args2, 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));
+ if (!avail)
+ 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;
+}
+
+/**
+ * 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;
+
+ if (!ab)
+ return;
+ va_start(args, fmt);
+ audit_log_vformat(ab, fmt, args);
+ va_end(args);
+}
+
+/**
+ * audit_log_n_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_n_hex(struct audit_buffer *ab, const unsigned char *buf,
+ size_t len)
+{
+ int i, 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 = len<<1;
+ if (new_len >= avail) {
+ /* Round the buffer request up to the next multiple */
+ new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
+ avail = audit_expand(ab, new_len);
+ if (!avail)
+ return;
+ }
+
+ ptr = skb_tail_pointer(skb);
+ for (i = 0; i < len; i++)
+ ptr = hex_byte_pack_upper(ptr, buf[i]);
+ *ptr = 0;
+ 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
+ */
+bool 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 true;
+ }
+ return false;
+}
+
+/**
+ * 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.
+ */
+void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
+ size_t len)
+{
+ if (audit_string_contains_control(string, len))
+ audit_log_n_hex(ab, string, len);
+ else
+ audit_log_n_string(ab, string, len);
+}
+
+/**
+ * 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,
+ const struct path *path)
+{
+ char *p, *pathname;
+
+ if (prefix)
+ audit_log_format(ab, "%s", prefix);
+
+ /* We will allow 11 spaces for ' (deleted)' to be appended */
+ pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
+ if (!pathname) {
+ audit_log_format(ab, "\"<no_memory>\"");
+ return;
+ }
+ 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_untrustedstring(ab, p);
+ kfree(pathname);
+}
+
+void audit_log_session_info(struct audit_buffer *ab)
+{
+ unsigned int sessionid = audit_get_sessionid(current);
+ uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
+
+ audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
+}
+
+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)");
+}
+
+int audit_log_task_context(struct audit_buffer *ab)
+{
+ char *ctx = NULL;
+ unsigned len;
+ int error;
+ u32 sid;
+
+ security_current_getsecid_subj(&sid);
+ if (!sid)
+ return 0;
+
+ error = security_secid_to_secctx(sid, &ctx, &len);
+ if (error) {
+ if (error != -EINVAL)
+ goto error_path;
+ return 0;
+ }
+
+ audit_log_format(ab, " subj=%s", ctx);
+ security_release_secctx(ctx, len);
+ return 0;
+
+error_path:
+ audit_panic("error in audit_log_task_context");
+ return error;
+}
+EXPORT_SYMBOL(audit_log_task_context);
+
+void audit_log_d_path_exe(struct audit_buffer *ab,
+ struct mm_struct *mm)
+{
+ struct file *exe_file;
+
+ if (!mm)
+ goto out_null;
+
+ exe_file = get_mm_exe_file(mm);
+ if (!exe_file)
+ goto out_null;
+
+ audit_log_d_path(ab, " exe=", &exe_file->f_path);
+ fput(exe_file);
+ return;
+out_null:
+ audit_log_format(ab, " exe=(null)");
+}
+
+struct tty_struct *audit_get_tty(void)
+{
+ struct tty_struct *tty = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&current->sighand->siglock, flags);
+ if (current->signal)
+ tty = tty_kref_get(current->signal->tty);
+ spin_unlock_irqrestore(&current->sighand->siglock, flags);
+ return tty;
+}
+
+void audit_put_tty(struct tty_struct *tty)
+{
+ tty_kref_put(tty);
+}
+
+void audit_log_task_info(struct audit_buffer *ab)
+{
+ const struct cred *cred;
+ char comm[sizeof(current->comm)];
+ struct tty_struct *tty;
+
+ if (!ab)
+ return;
+
+ cred = current_cred();
+ tty = audit_get_tty();
+ audit_log_format(ab,
+ " ppid=%d pid=%d auid=%u uid=%u gid=%u"
+ " euid=%u suid=%u fsuid=%u"
+ " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
+ task_ppid_nr(current),
+ task_tgid_nr(current),
+ from_kuid(&init_user_ns, audit_get_loginuid(current)),
+ from_kuid(&init_user_ns, cred->uid),
+ from_kgid(&init_user_ns, cred->gid),
+ from_kuid(&init_user_ns, cred->euid),
+ from_kuid(&init_user_ns, cred->suid),
+ from_kuid(&init_user_ns, cred->fsuid),
+ from_kgid(&init_user_ns, cred->egid),
+ from_kgid(&init_user_ns, cred->sgid),
+ from_kgid(&init_user_ns, cred->fsgid),
+ tty ? tty_name(tty) : "(none)",
+ audit_get_sessionid(current));
+ audit_put_tty(tty);
+ audit_log_format(ab, " comm=");
+ audit_log_untrustedstring(ab, get_task_comm(comm, current));
+ audit_log_d_path_exe(ab, current->mm);
+ audit_log_task_context(ab);
+}
+EXPORT_SYMBOL(audit_log_task_info);
+
+/**
+ * audit_log_path_denied - report a path restriction denial
+ * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc)
+ * @operation: specific operation name
+ */
+void audit_log_path_denied(int type, const char *operation)
+{
+ struct audit_buffer *ab;
+
+ if (!audit_enabled || audit_dummy_context())
+ return;
+
+ /* Generate log with subject, operation, outcome. */
+ ab = audit_log_start(audit_context(), GFP_KERNEL, type);
+ if (!ab)
+ return;
+ audit_log_format(ab, "op=%s", operation);
+ audit_log_task_info(ab);
+ audit_log_format(ab, " res=0");
+ audit_log_end(ab);
+}
+
+/* global counter which is incremented every time something logs in */
+static atomic_t session_id = ATOMIC_INIT(0);
+
+static int audit_set_loginuid_perm(kuid_t loginuid)
+{
+ /* if we are unset, we don't need privs */
+ if (!audit_loginuid_set(current))
+ return 0;
+ /* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
+ if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
+ return -EPERM;
+ /* it is set, you need permission */
+ if (!capable(CAP_AUDIT_CONTROL))
+ return -EPERM;
+ /* reject if this is not an unset and we don't allow that */
+ if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID)
+ && uid_valid(loginuid))
+ return -EPERM;
+ return 0;
+}
+
+static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
+ unsigned int oldsessionid,
+ unsigned int sessionid, int rc)
+{
+ struct audit_buffer *ab;
+ uid_t uid, oldloginuid, loginuid;
+ struct tty_struct *tty;
+
+ if (!audit_enabled)
+ return;
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
+ if (!ab)
+ return;
+
+ uid = from_kuid(&init_user_ns, task_uid(current));
+ oldloginuid = from_kuid(&init_user_ns, koldloginuid);
+ loginuid = from_kuid(&init_user_ns, kloginuid);
+ tty = audit_get_tty();
+
+ audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
+ audit_log_task_context(ab);
+ audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
+ oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
+ oldsessionid, sessionid, !rc);
+ audit_put_tty(tty);
+ audit_log_end(ab);
+}
+
+/**
+ * audit_set_loginuid - set current task's loginuid
+ * @loginuid: loginuid value
+ *
+ * Returns 0.
+ *
+ * Called (set) from fs/proc/base.c::proc_loginuid_write().
+ */
+int audit_set_loginuid(kuid_t loginuid)
+{
+ unsigned int oldsessionid, sessionid = AUDIT_SID_UNSET;
+ kuid_t oldloginuid;
+ int rc;
+
+ oldloginuid = audit_get_loginuid(current);
+ oldsessionid = audit_get_sessionid(current);
+
+ rc = audit_set_loginuid_perm(loginuid);
+ if (rc)
+ goto out;
+
+ /* are we setting or clearing? */
+ if (uid_valid(loginuid)) {
+ sessionid = (unsigned int)atomic_inc_return(&session_id);
+ if (unlikely(sessionid == AUDIT_SID_UNSET))
+ sessionid = (unsigned int)atomic_inc_return(&session_id);
+ }
+
+ current->sessionid = sessionid;
+ current->loginuid = loginuid;
+out:
+ audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
+ return rc;
+}
+
+/**
+ * audit_signal_info - record signal info for shutting down audit subsystem
+ * @sig: signal value
+ * @t: task being signaled
+ *
+ * If the audit subsystem is being terminated, record the task (pid)
+ * and uid that is doing that.
+ */
+int audit_signal_info(int sig, struct task_struct *t)
+{
+ kuid_t uid = current_uid(), auid;
+
+ if (auditd_test_task(t) &&
+ (sig == SIGTERM || sig == SIGHUP ||
+ sig == SIGUSR1 || sig == SIGUSR2)) {
+ audit_sig_pid = task_tgid_nr(current);
+ auid = audit_get_loginuid(current);
+ if (uid_valid(auid))
+ audit_sig_uid = auid;
+ else
+ audit_sig_uid = uid;
+ security_current_getsecid_subj(&audit_sig_sid);
+ }
+
+ return audit_signal_info_syscall(t);
+}
+
+/**
+ * audit_log_end - end one audit record
+ * @ab: the audit_buffer
+ *
+ * We can not do a netlink send inside an irq context because it blocks (last
+ * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
+ * queue and a kthread is scheduled to remove them from the queue outside the
+ * irq context. May be called in any context.
+ */
+void audit_log_end(struct audit_buffer *ab)
+{
+ struct sk_buff *skb;
+ struct nlmsghdr *nlh;
+
+ if (!ab)
+ return;
+
+ if (audit_rate_check()) {
+ skb = ab->skb;
+ ab->skb = NULL;
+
+ /* setup the netlink header, see the comments in
+ * kauditd_send_multicast_skb() for length quirks */
+ nlh = nlmsg_hdr(skb);
+ nlh->nlmsg_len = skb->len - NLMSG_HDRLEN;
+
+ /* queue the netlink packet and poke the kauditd thread */
+ skb_queue_tail(&audit_queue, skb);
+ wake_up_interruptible(&kauditd_wait);
+ } else
+ audit_log_lost("rate limit exceeded");
+
+ audit_buffer_free(ab);
+}
+
+/**
+ * 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, gfp_mask, type);
+ if (ab) {
+ va_start(args, fmt);
+ audit_log_vformat(ab, fmt, args);
+ va_end(args);
+ audit_log_end(ab);
+ }
+}
+
+EXPORT_SYMBOL(audit_log_start);
+EXPORT_SYMBOL(audit_log_end);
+EXPORT_SYMBOL(audit_log_format);
+EXPORT_SYMBOL(audit_log);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 18:41:00 +0000