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kernel/audit.c
39.4 KB
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/* audit.c -- Auditing support |
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* Gateway between the kernel (e.g., selinux) and the user-space audit daemon. * System-call specific features have moved to auditsc.c * |
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* Copyright 2003-2007 Red Hat Inc., Durham, North Carolina. |
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* All Rights Reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Written by Rickard E. (Rik) Faith <faith@redhat.com> * |
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* Goals: 1) Integrate fully with Security Modules. |
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* 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. * |
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* Example user-space utilities: http://people.redhat.com/sgrubb/audit/ |
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*/ #include <linux/init.h> |
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#include <asm/types.h> |
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#include <asm/atomic.h> |
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#include <linux/mm.h> #include <linux/module.h> |
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#include <linux/err.h> #include <linux/kthread.h> |
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#include <linux/audit.h> #include <net/sock.h> |
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#include <net/netlink.h> |
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#include <linux/skbuff.h> #include <linux/netlink.h> |
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#include <linux/inotify.h> |
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#include <linux/freezer.h> |
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#include <linux/tty.h> |
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#include "audit.h" |
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/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
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* (Initialization happens after skb_init is called.) */ |
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#define AUDIT_DISABLED -1 #define AUDIT_UNINITIALIZED 0 #define AUDIT_INITIALIZED 1 |
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static int audit_initialized; |
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#define AUDIT_OFF 0 #define AUDIT_ON 1 #define AUDIT_LOCKED 2 |
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int audit_enabled; |
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int audit_ever_enabled; |
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/* 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; |
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/* * 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. */ |
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int audit_pid; |
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static int audit_nlk_pid; |
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/* If audit_rate_limit is non-zero, limit the rate of sending audit records |
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* to that number per second. This prevents DoS attacks, but results in * audit records being dropped. */ static int audit_rate_limit; /* Number of outstanding audit_buffers allowed. */ static int audit_backlog_limit = 64; |
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static int audit_backlog_wait_time = 60 * HZ; static int audit_backlog_wait_overflow = 0; |
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/* The identity of the user shutting down the audit system. */ uid_t audit_sig_uid = -1; pid_t audit_sig_pid = -1; |
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u32 audit_sig_sid = 0; |
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/* 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); /* The netlink socket. */ static struct sock *audit_sock; |
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/* Hash for inode-based rules */ struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; |
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/* The audit_freelist is a list of pre-allocated audit buffers (if more |
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* than AUDIT_MAXFREE are in use, the audit buffer is freed instead of * being placed on the freelist). */ |
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static DEFINE_SPINLOCK(audit_freelist_lock); |
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static int audit_freelist_count; |
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static LIST_HEAD(audit_freelist); |
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static struct sk_buff_head audit_skb_queue; |
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/* queue of skbs to send to auditd when/if it comes back */ static struct sk_buff_head audit_skb_hold_queue; |
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static struct task_struct *kauditd_task; static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); |
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static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
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/* Serialize requests from userspace. */ |
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DEFINE_MUTEX(audit_cmd_mutex); |
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/* 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 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ #define AUDIT_MAXFREE (2*NR_CPUS) /* 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 list_head list; |
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struct sk_buff *skb; /* formatted skb ready to send */ |
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struct audit_context *ctx; /* NULL or associated context */ |
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gfp_t gfp_mask; |
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}; |
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struct audit_reply { int pid; struct sk_buff *skb; }; |
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static void audit_set_pid(struct audit_buffer *ab, pid_t pid) { |
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if (ab) { struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); nlh->nlmsg_pid = pid; } |
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} |
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void audit_panic(const char *message) |
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{ switch (audit_failure) { case AUDIT_FAIL_SILENT: break; case AUDIT_FAIL_PRINTK: |
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if (printk_ratelimit()) printk(KERN_ERR "audit: %s ", message); |
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break; case AUDIT_FAIL_PANIC: |
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/* test audit_pid since printk is always losey, why bother? */ if (audit_pid) panic("audit: %s ", message); |
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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; unsigned long elapsed; int retval = 0; if (!audit_rate_limit) return 1; spin_lock_irqsave(&lock, flags); if (++messages < audit_rate_limit) { retval = 1; } else { now = jiffies; elapsed = now - last_check; if (elapsed > HZ) { last_check = now; messages = 0; retval = 1; } } spin_unlock_irqrestore(&lock, flags); return retval; } |
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/** * 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. */ |
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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 (now - last_msg > HZ) { print = 1; last_msg = now; } spin_unlock_irqrestore(&lock, flags); } if (print) { |
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if (printk_ratelimit()) printk(KERN_WARNING "audit: audit_lost=%d audit_rate_limit=%d " "audit_backlog_limit=%d ", atomic_read(&audit_lost), audit_rate_limit, audit_backlog_limit); |
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audit_panic(message); } |
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} |
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static int audit_log_config_change(char *function_name, int new, int old, |
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uid_t loginuid, u32 sessionid, u32 sid, int allow_changes) |
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{ |
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struct audit_buffer *ab; int rc = 0; |
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ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
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audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new, old, loginuid, sessionid); |
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if (sid) { char *ctx = NULL; u32 len; |
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rc = security_secid_to_secctx(sid, &ctx, &len); |
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if (rc) { audit_log_format(ab, " sid=%u", sid); allow_changes = 0; /* Something weird, deny request */ } else { audit_log_format(ab, " subj=%s", ctx); |
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security_release_secctx(ctx, len); |
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} |
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} |
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audit_log_format(ab, " res=%d", allow_changes); audit_log_end(ab); |
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return rc; |
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} |
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static int audit_do_config_change(char *function_name, int *to_change, |
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int new, uid_t loginuid, u32 sessionid, u32 sid) |
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{ |
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int allow_changes, rc = 0, old = *to_change; |
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/* check if we are locked */ |
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if (audit_enabled == AUDIT_LOCKED) allow_changes = 0; |
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else |
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allow_changes = 1; |
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if (audit_enabled != AUDIT_OFF) { |
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rc = audit_log_config_change(function_name, new, old, loginuid, sessionid, sid, allow_changes); |
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if (rc) allow_changes = 0; |
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} |
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/* If we are allowed, make the change */ |
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if (allow_changes == 1) *to_change = new; |
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/* Not allowed, update reason */ else if (rc == 0) rc = -EPERM; return rc; |
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} |
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static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid, u32 sid) |
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{ |
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return audit_do_config_change("audit_rate_limit", &audit_rate_limit, |
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limit, loginuid, sessionid, sid); |
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} |
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static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid, u32 sid) |
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{ return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, |
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limit, loginuid, sessionid, sid); |
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} |
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static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid) |
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{ |
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int rc; |
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if (state < AUDIT_OFF || state > AUDIT_LOCKED) return -EINVAL; |
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rc = audit_do_config_change("audit_enabled", &audit_enabled, state, |
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loginuid, sessionid, sid); |
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if (!rc) audit_ever_enabled |= !!state; return rc; |
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} |
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static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid) |
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{ |
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if (state != AUDIT_FAIL_SILENT && state != AUDIT_FAIL_PRINTK && state != AUDIT_FAIL_PANIC) return -EINVAL; |
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return audit_do_config_change("audit_failure", &audit_failure, state, |
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loginuid, sessionid, sid); |
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} |
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/* * 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); } |
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/* * 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 ", nlh->nlmsg_type, data); else audit_log_lost("printk limit exceeded "); } audit_hold_skb(skb); } |
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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); /* Shoudn't happen */ printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d ", audit_pid); audit_log_lost("auditd dissapeared "); audit_pid = 0; /* we might get lucky and get this in the next auditd */ audit_hold_skb(skb); } else /* drop the extra reference if sent ok */ kfree_skb(skb); } |
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static int kauditd_thread(void *dummy) |
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{ struct sk_buff *skb; |
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set_freezable(); |
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while (!kthread_should_stop()) { |
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/* * 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); } } } |
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skb = skb_dequeue(&audit_skb_queue); |
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wake_up(&audit_backlog_wait); |
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if (skb) { |
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if (audit_pid) kauditd_send_skb(skb); |
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else audit_printk_skb(skb); |
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} else { DECLARE_WAITQUEUE(wait, current); set_current_state(TASK_INTERRUPTIBLE); add_wait_queue(&kauditd_wait, &wait); |
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if (!skb_queue_len(&audit_skb_queue)) { try_to_freeze(); |
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schedule(); |
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} |
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__set_current_state(TASK_RUNNING); remove_wait_queue(&kauditd_wait, &wait); } } |
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return 0; |
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} |
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static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid) |
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{ struct task_struct *tsk; int err; read_lock(&tasklist_lock); |
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tsk = find_task_by_vpid(pid); |
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err = -ESRCH; if (!tsk) goto out; err = 0; spin_lock_irq(&tsk->sighand->siglock); if (!tsk->signal->audit_tty) err = -EPERM; spin_unlock_irq(&tsk->sighand->siglock); if (err) goto out; |
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tty_audit_push_task(tsk, loginuid, sessionid); |
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out: read_unlock(&tasklist_lock); return err; } |
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int audit_send_list(void *_dest) { struct audit_netlink_list *dest = _dest; int pid = dest->pid; struct sk_buff *skb; /* wait for parent to finish and send an ACK */ |
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mutex_lock(&audit_cmd_mutex); mutex_unlock(&audit_cmd_mutex); |
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while ((skb = __skb_dequeue(&dest->q)) != NULL) netlink_unicast(audit_sock, skb, pid, 0); kfree(dest); return 0; } struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, int multi, void *payload, int size) { struct sk_buff *skb; struct nlmsghdr *nlh; |
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void *data; int flags = multi ? NLM_F_MULTI : 0; int t = done ? NLMSG_DONE : type; |
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skb = nlmsg_new(size, GFP_KERNEL); |
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if (!skb) return NULL; |
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nlh = NLMSG_NEW(skb, pid, seq, t, size, flags); data = NLMSG_DATA(nlh); |
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memcpy(data, payload, size); return skb; |
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nlmsg_failure: /* Used by NLMSG_NEW */ |
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if (skb) kfree_skb(skb); return NULL; } |
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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; } |
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/** * audit_send_reply - send an audit reply message via netlink * @pid: process id to send reply to * @seq: sequence number * @type: audit message type * @done: done (last) flag * @multi: multi-part message flag * @payload: payload data * @size: payload size * * Allocates an skb, builds the netlink message, and sends it to the pid. * No failure notifications. */ |
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void audit_send_reply(int pid, int seq, int type, int done, int multi, void *payload, int size) { |
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struct sk_buff *skb; struct task_struct *tsk; struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), GFP_KERNEL); if (!reply) return; |
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skb = audit_make_reply(pid, seq, type, done, multi, payload, size); |
1da177e4c
|
549 |
if (!skb) |
fcaf1eb86
|
550 |
goto out; |
f09ac9db2
|
551 552 553 554 555 |
reply->pid = pid; reply->skb = skb; tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); |
fcaf1eb86
|
556 557 558 559 560 |
if (!IS_ERR(tsk)) return; kfree_skb(skb); out: kfree(reply); |
1da177e4c
|
561 562 563 564 565 566 |
} /* * Check for appropriate CAP_AUDIT_ capabilities on incoming audit * control messages. */ |
c7bdb545d
|
567 |
static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4c
|
568 569 570 571 572 573 |
{ int err = 0; switch (msg_type) { case AUDIT_GET: case AUDIT_LIST: |
93315ed6d
|
574 |
case AUDIT_LIST_RULES: |
1da177e4c
|
575 576 |
case AUDIT_SET: case AUDIT_ADD: |
93315ed6d
|
577 |
case AUDIT_ADD_RULE: |
1da177e4c
|
578 |
case AUDIT_DEL: |
93315ed6d
|
579 |
case AUDIT_DEL_RULE: |
c2f0c7c35
|
580 |
case AUDIT_SIGNAL_INFO: |
522ed7767
|
581 582 |
case AUDIT_TTY_GET: case AUDIT_TTY_SET: |
74c3cbe33
|
583 584 |
case AUDIT_TRIM: case AUDIT_MAKE_EQUIV: |
c7bdb545d
|
585 |
if (security_netlink_recv(skb, CAP_AUDIT_CONTROL)) |
1da177e4c
|
586 587 |
err = -EPERM; break; |
05474106a
|
588 |
case AUDIT_USER: |
039b6b3ed
|
589 590 |
case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: |
c7bdb545d
|
591 |
if (security_netlink_recv(skb, CAP_AUDIT_WRITE)) |
1da177e4c
|
592 593 594 595 596 597 598 599 |
err = -EPERM; break; default: /* bad msg */ err = -EINVAL; } return err; } |
50397bd1e
|
600 |
static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type, |
2532386f4
|
601 602 |
u32 pid, u32 uid, uid_t auid, u32 ses, u32 sid) |
50397bd1e
|
603 604 605 606 607 608 609 610 611 612 613 |
{ int rc = 0; char *ctx = NULL; u32 len; if (!audit_enabled) { *ab = NULL; return rc; } *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); |
2532386f4
|
614 615 |
audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u", pid, uid, auid, ses); |
50397bd1e
|
616 |
if (sid) { |
2a862b32f
|
617 |
rc = security_secid_to_secctx(sid, &ctx, &len); |
50397bd1e
|
618 619 |
if (rc) audit_log_format(*ab, " ssid=%u", sid); |
2a862b32f
|
620 |
else { |
50397bd1e
|
621 |
audit_log_format(*ab, " subj=%s", ctx); |
2a862b32f
|
622 623 |
security_release_secctx(ctx, len); } |
50397bd1e
|
624 625 626 627 |
} return rc; } |
1da177e4c
|
628 629 |
static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) { |
e7c349701
|
630 |
u32 uid, pid, seq, sid; |
1da177e4c
|
631 632 633 |
void *data; struct audit_status *status_get, status_set; int err; |
c04049939
|
634 |
struct audit_buffer *ab; |
1da177e4c
|
635 |
u16 msg_type = nlh->nlmsg_type; |
c94c257c8
|
636 |
uid_t loginuid; /* loginuid of sender */ |
2532386f4
|
637 |
u32 sessionid; |
e1396065e
|
638 |
struct audit_sig_info *sig_data; |
50397bd1e
|
639 |
char *ctx = NULL; |
e1396065e
|
640 |
u32 len; |
1da177e4c
|
641 |
|
c7bdb545d
|
642 |
err = audit_netlink_ok(skb, msg_type); |
1da177e4c
|
643 644 |
if (err) return err; |
b0dd25a82
|
645 646 |
/* As soon as there's any sign of userspace auditd, * start kauditd to talk to it */ |
b7d112581
|
647 648 649 650 651 652 653 |
if (!kauditd_task) kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); if (IS_ERR(kauditd_task)) { err = PTR_ERR(kauditd_task); kauditd_task = NULL; return err; } |
1da177e4c
|
654 655 |
pid = NETLINK_CREDS(skb)->pid; uid = NETLINK_CREDS(skb)->uid; |
c94c257c8
|
656 |
loginuid = NETLINK_CB(skb).loginuid; |
2532386f4
|
657 |
sessionid = NETLINK_CB(skb).sessionid; |
e7c349701
|
658 |
sid = NETLINK_CB(skb).sid; |
1da177e4c
|
659 660 661 662 663 664 665 666 667 668 669 |
seq = nlh->nlmsg_seq; data = NLMSG_DATA(nlh); switch (msg_type) { case AUDIT_GET: status_set.enabled = audit_enabled; status_set.failure = audit_failure; status_set.pid = audit_pid; status_set.rate_limit = audit_rate_limit; status_set.backlog_limit = audit_backlog_limit; status_set.lost = atomic_read(&audit_lost); |
b7d112581
|
670 |
status_set.backlog = skb_queue_len(&audit_skb_queue); |
1da177e4c
|
671 672 673 674 675 676 677 678 |
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0, &status_set, sizeof(status_set)); break; case AUDIT_SET: if (nlh->nlmsg_len < sizeof(struct audit_status)) return -EINVAL; status_get = (struct audit_status *)data; if (status_get->mask & AUDIT_STATUS_ENABLED) { |
ce29b682e
|
679 |
err = audit_set_enabled(status_get->enabled, |
2532386f4
|
680 |
loginuid, sessionid, sid); |
20c6aaa39
|
681 682 |
if (err < 0) return err; |
1da177e4c
|
683 684 |
} if (status_get->mask & AUDIT_STATUS_FAILURE) { |
ce29b682e
|
685 |
err = audit_set_failure(status_get->failure, |
2532386f4
|
686 |
loginuid, sessionid, sid); |
20c6aaa39
|
687 688 |
if (err < 0) return err; |
1da177e4c
|
689 690 |
} if (status_get->mask & AUDIT_STATUS_PID) { |
1a6b9f231
|
691 692 693 694 695 |
int new_pid = status_get->pid; if (audit_enabled != AUDIT_OFF) audit_log_config_change("audit_pid", new_pid, audit_pid, loginuid, |
2532386f4
|
696 |
sessionid, sid, 1); |
1a6b9f231
|
697 698 |
audit_pid = new_pid; |
75c0371a2
|
699 |
audit_nlk_pid = NETLINK_CB(skb).pid; |
1da177e4c
|
700 |
} |
20c6aaa39
|
701 |
if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { |
5d136a010
|
702 |
err = audit_set_rate_limit(status_get->rate_limit, |
2532386f4
|
703 |
loginuid, sessionid, sid); |
20c6aaa39
|
704 705 706 |
if (err < 0) return err; } |
1da177e4c
|
707 |
if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
5d136a010
|
708 |
err = audit_set_backlog_limit(status_get->backlog_limit, |
2532386f4
|
709 |
loginuid, sessionid, sid); |
1da177e4c
|
710 |
break; |
05474106a
|
711 |
case AUDIT_USER: |
039b6b3ed
|
712 713 |
case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: |
4a4cd633b
|
714 715 |
if (!audit_enabled && msg_type != AUDIT_USER_AVC) return 0; |
d8de72473
|
716 |
err = audit_filter_user(&NETLINK_CB(skb)); |
4a4cd633b
|
717 718 |
if (err == 1) { err = 0; |
522ed7767
|
719 |
if (msg_type == AUDIT_USER_TTY) { |
2532386f4
|
720 721 |
err = audit_prepare_user_tty(pid, loginuid, sessionid); |
522ed7767
|
722 723 724 |
if (err) break; } |
50397bd1e
|
725 |
audit_log_common_recv_msg(&ab, msg_type, pid, uid, |
2532386f4
|
726 |
loginuid, sessionid, sid); |
50397bd1e
|
727 728 729 730 731 732 733 734 735 |
if (msg_type != AUDIT_USER_TTY) audit_log_format(ab, " msg='%.1024s'", (char *)data); else { int size; audit_log_format(ab, " msg="); size = nlmsg_len(nlh); |
55ad2f8d3
|
736 737 738 |
if (size > 0 && ((unsigned char *)data)[size - 1] == '\0') size--; |
b556f8ad5
|
739 |
audit_log_n_untrustedstring(ab, data, size); |
4a4cd633b
|
740 |
} |
50397bd1e
|
741 742 |
audit_set_pid(ab, pid); audit_log_end(ab); |
0f45aa18e
|
743 |
} |
1da177e4c
|
744 745 746 |
break; case AUDIT_ADD: case AUDIT_DEL: |
93315ed6d
|
747 |
if (nlmsg_len(nlh) < sizeof(struct audit_rule)) |
1da177e4c
|
748 |
return -EINVAL; |
1a6b9f231
|
749 |
if (audit_enabled == AUDIT_LOCKED) { |
50397bd1e
|
750 |
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, |
2532386f4
|
751 |
uid, loginuid, sessionid, sid); |
50397bd1e
|
752 753 754 755 |
audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); audit_log_end(ab); |
6a01b07fa
|
756 757 |
return -EPERM; } |
1da177e4c
|
758 759 |
/* fallthrough */ case AUDIT_LIST: |
13d5ef97f
|
760 |
err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid, |
93315ed6d
|
761 |
uid, seq, data, nlmsg_len(nlh), |
2532386f4
|
762 |
loginuid, sessionid, sid); |
93315ed6d
|
763 764 765 766 767 |
break; case AUDIT_ADD_RULE: case AUDIT_DEL_RULE: if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) return -EINVAL; |
1a6b9f231
|
768 |
if (audit_enabled == AUDIT_LOCKED) { |
50397bd1e
|
769 |
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, |
2532386f4
|
770 |
uid, loginuid, sessionid, sid); |
50397bd1e
|
771 772 773 774 |
audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); audit_log_end(ab); |
6a01b07fa
|
775 776 |
return -EPERM; } |
93315ed6d
|
777 778 |
/* fallthrough */ case AUDIT_LIST_RULES: |
13d5ef97f
|
779 |
err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid, |
93315ed6d
|
780 |
uid, seq, data, nlmsg_len(nlh), |
2532386f4
|
781 |
loginuid, sessionid, sid); |
1da177e4c
|
782 |
break; |
74c3cbe33
|
783 784 |
case AUDIT_TRIM: audit_trim_trees(); |
50397bd1e
|
785 786 |
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, |
2532386f4
|
787 |
uid, loginuid, sessionid, sid); |
50397bd1e
|
788 |
|
74c3cbe33
|
789 790 791 792 793 794 |
audit_log_format(ab, " op=trim res=1"); audit_log_end(ab); break; case AUDIT_MAKE_EQUIV: { void *bufp = data; u32 sizes[2]; |
7719e437f
|
795 |
size_t msglen = nlmsg_len(nlh); |
74c3cbe33
|
796 797 798 |
char *old, *new; err = -EINVAL; |
7719e437f
|
799 |
if (msglen < 2 * sizeof(u32)) |
74c3cbe33
|
800 801 802 |
break; memcpy(sizes, bufp, 2 * sizeof(u32)); bufp += 2 * sizeof(u32); |
7719e437f
|
803 804 |
msglen -= 2 * sizeof(u32); old = audit_unpack_string(&bufp, &msglen, sizes[0]); |
74c3cbe33
|
805 806 807 808 |
if (IS_ERR(old)) { err = PTR_ERR(old); break; } |
7719e437f
|
809 |
new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe33
|
810 811 812 813 814 815 816 |
if (IS_ERR(new)) { err = PTR_ERR(new); kfree(old); break; } /* OK, here comes... */ err = audit_tag_tree(old, new); |
50397bd1e
|
817 |
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, |
2532386f4
|
818 |
uid, loginuid, sessionid, sid); |
50397bd1e
|
819 |
|
74c3cbe33
|
820 821 822 823 824 825 826 827 828 829 |
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; } |
c2f0c7c35
|
830 |
case AUDIT_SIGNAL_INFO: |
939cbf260
|
831 832 833 834 835 836 |
len = 0; if (audit_sig_sid) { err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); if (err) return err; } |
e1396065e
|
837 838 |
sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); if (!sig_data) { |
939cbf260
|
839 840 |
if (audit_sig_sid) security_release_secctx(ctx, len); |
e1396065e
|
841 842 843 844 |
return -ENOMEM; } sig_data->uid = audit_sig_uid; sig_data->pid = audit_sig_pid; |
939cbf260
|
845 846 847 848 |
if (audit_sig_sid) { memcpy(sig_data->ctx, ctx, len); security_release_secctx(ctx, len); } |
5600b8927
|
849 |
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, |
e1396065e
|
850 851 |
0, 0, sig_data, sizeof(*sig_data) + len); kfree(sig_data); |
c2f0c7c35
|
852 |
break; |
522ed7767
|
853 854 855 856 857 |
case AUDIT_TTY_GET: { struct audit_tty_status s; struct task_struct *tsk; read_lock(&tasklist_lock); |
4a761b8c1
|
858 |
tsk = find_task_by_vpid(pid); |
522ed7767
|
859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 |
if (!tsk) err = -ESRCH; else { spin_lock_irq(&tsk->sighand->siglock); s.enabled = tsk->signal->audit_tty != 0; spin_unlock_irq(&tsk->sighand->siglock); } read_unlock(&tasklist_lock); audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); break; } case AUDIT_TTY_SET: { struct audit_tty_status *s; struct task_struct *tsk; if (nlh->nlmsg_len < sizeof(struct audit_tty_status)) return -EINVAL; s = data; if (s->enabled != 0 && s->enabled != 1) return -EINVAL; read_lock(&tasklist_lock); |
4a761b8c1
|
881 |
tsk = find_task_by_vpid(pid); |
522ed7767
|
882 883 884 885 886 887 888 889 890 891 |
if (!tsk) err = -ESRCH; else { spin_lock_irq(&tsk->sighand->siglock); tsk->signal->audit_tty = s->enabled != 0; spin_unlock_irq(&tsk->sighand->siglock); } read_unlock(&tasklist_lock); break; } |
1da177e4c
|
892 893 894 895 896 897 898 |
default: err = -EINVAL; break; } return err < 0 ? err : 0; } |
b0dd25a82
|
899 |
/* |
ea7ae60bf
|
900 901 |
* Get message from skb. Each message is processed by audit_receive_msg. * Malformed skbs with wrong length are discarded silently. |
b0dd25a82
|
902 |
*/ |
2a0a6ebee
|
903 |
static void audit_receive_skb(struct sk_buff *skb) |
1da177e4c
|
904 |
{ |
ea7ae60bf
|
905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 |
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)) |
1da177e4c
|
920 |
netlink_ack(skb, nlh, err); |
ea7ae60bf
|
921 922 |
nlh = NLMSG_NEXT(nlh, len); |
1da177e4c
|
923 |
} |
1da177e4c
|
924 925 926 |
} /* Receive messages from netlink socket. */ |
cd40b7d39
|
927 |
static void audit_receive(struct sk_buff *skb) |
1da177e4c
|
928 |
{ |
f368c07d7
|
929 |
mutex_lock(&audit_cmd_mutex); |
cd40b7d39
|
930 |
audit_receive_skb(skb); |
f368c07d7
|
931 |
mutex_unlock(&audit_cmd_mutex); |
1da177e4c
|
932 |
} |
1da177e4c
|
933 934 935 |
/* Initialize audit support at boot time. */ static int __init audit_init(void) { |
f368c07d7
|
936 |
int i; |
f368c07d7
|
937 |
|
a3f07114e
|
938 939 |
if (audit_initialized == AUDIT_DISABLED) return 0; |
1da177e4c
|
940 941 942 |
printk(KERN_INFO "audit: initializing netlink socket (%s) ", audit_default ? "enabled" : "disabled"); |
b4b510290
|
943 944 |
audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0, audit_receive, NULL, THIS_MODULE); |
1da177e4c
|
945 946 |
if (!audit_sock) audit_panic("cannot initialize netlink socket"); |
71e1c784b
|
947 948 |
else audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; |
1da177e4c
|
949 |
|
b7d112581
|
950 |
skb_queue_head_init(&audit_skb_queue); |
f3d357b09
|
951 |
skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114e
|
952 |
audit_initialized = AUDIT_INITIALIZED; |
1da177e4c
|
953 |
audit_enabled = audit_default; |
b593d384e
|
954 |
audit_ever_enabled |= !!audit_default; |
3dc7e3153
|
955 |
|
9ad9ad385
|
956 |
audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d7
|
957 |
|
f368c07d7
|
958 959 |
for (i = 0; i < AUDIT_INODE_BUCKETS; i++) INIT_LIST_HEAD(&audit_inode_hash[i]); |
f368c07d7
|
960 |
|
1da177e4c
|
961 962 |
return 0; } |
1da177e4c
|
963 964 965 966 967 968 |
__initcall(audit_init); /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ static int __init audit_enable(char *str) { audit_default = !!simple_strtol(str, NULL, 0); |
a3f07114e
|
969 970 971 972 973 974 |
if (!audit_default) audit_initialized = AUDIT_DISABLED; printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled"); if (audit_initialized == AUDIT_INITIALIZED) { |
1da177e4c
|
975 |
audit_enabled = audit_default; |
b593d384e
|
976 |
audit_ever_enabled |= !!audit_default; |
a3f07114e
|
977 978 979 980 |
} else if (audit_initialized == AUDIT_UNINITIALIZED) { printk(" (after initialization)"); } else { printk(" (until reboot)"); |
b593d384e
|
981 |
} |
a3f07114e
|
982 983 |
printk(" "); |
9b41046cd
|
984 |
return 1; |
1da177e4c
|
985 986 987 |
} __setup("audit=", audit_enable); |
16e1904e6
|
988 989 990 |
static void audit_buffer_free(struct audit_buffer *ab) { unsigned long flags; |
8fc6115c2
|
991 992 |
if (!ab) return; |
5ac52f33b
|
993 994 |
if (ab->skb) kfree_skb(ab->skb); |
b7d112581
|
995 |
|
16e1904e6
|
996 |
spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a010
|
997 |
if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e6
|
998 |
kfree(ab); |
5d136a010
|
999 1000 |
else { audit_freelist_count++; |
16e1904e6
|
1001 |
list_add(&ab->list, &audit_freelist); |
5d136a010
|
1002 |
} |
16e1904e6
|
1003 1004 |
spin_unlock_irqrestore(&audit_freelist_lock, flags); } |
c04049939
|
1005 |
static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66fb
|
1006 |
gfp_t gfp_mask, int type) |
16e1904e6
|
1007 1008 1009 |
{ unsigned long flags; struct audit_buffer *ab = NULL; |
c04049939
|
1010 |
struct nlmsghdr *nlh; |
16e1904e6
|
1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 |
spin_lock_irqsave(&audit_freelist_lock, flags); if (!list_empty(&audit_freelist)) { ab = list_entry(audit_freelist.next, struct audit_buffer, list); list_del(&ab->list); --audit_freelist_count; } spin_unlock_irqrestore(&audit_freelist_lock, flags); if (!ab) { |
4332bdd33
|
1022 |
ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e6
|
1023 |
if (!ab) |
8fc6115c2
|
1024 |
goto err; |
16e1904e6
|
1025 |
} |
8fc6115c2
|
1026 |
|
b7d112581
|
1027 |
ab->ctx = ctx; |
9ad9ad385
|
1028 |
ab->gfp_mask = gfp_mask; |
ee080e6ce
|
1029 1030 1031 1032 1033 1034 |
ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); if (!ab->skb) goto nlmsg_failure; nlh = NLMSG_NEW(ab->skb, 0, 0, type, 0, 0); |
16e1904e6
|
1035 |
return ab; |
ee080e6ce
|
1036 1037 1038 1039 |
nlmsg_failure: /* Used by NLMSG_NEW */ kfree_skb(ab->skb); ab->skb = NULL; |
8fc6115c2
|
1040 1041 1042 |
err: audit_buffer_free(ab); return NULL; |
16e1904e6
|
1043 |
} |
1da177e4c
|
1044 |
|
b0dd25a82
|
1045 1046 1047 1048 |
/** * audit_serial - compute a serial number for the audit record * * Compute a serial number for the audit record. Audit records are |
bfb4496e7
|
1049 1050 1051 1052 1053 1054 1055 |
* 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. * |
bfb4496e7
|
1056 1057 1058 1059 |
* 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 |
b0dd25a82
|
1060 1061 |
* halts). */ |
bfb4496e7
|
1062 1063 |
unsigned int audit_serial(void) { |
34af946a2
|
1064 |
static DEFINE_SPINLOCK(serial_lock); |
d5b454f2c
|
1065 1066 1067 1068 |
static unsigned int serial = 0; unsigned long flags; unsigned int ret; |
bfb4496e7
|
1069 |
|
d5b454f2c
|
1070 |
spin_lock_irqsave(&serial_lock, flags); |
bfb4496e7
|
1071 |
do { |
ce625a801
|
1072 1073 |
ret = ++serial; } while (unlikely(!ret)); |
d5b454f2c
|
1074 |
spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e7
|
1075 |
|
d5b454f2c
|
1076 |
return ret; |
bfb4496e7
|
1077 |
} |
5600b8927
|
1078 |
static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e7
|
1079 1080 |
struct timespec *t, unsigned int *serial) { |
48887e63d
|
1081 |
if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e7
|
1082 1083 1084 1085 |
*t = CURRENT_TIME; *serial = audit_serial(); } } |
1da177e4c
|
1086 1087 1088 1089 1090 1091 |
/* 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 tsk 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, tsk * should be NULL. */ |
9ad9ad385
|
1092 |
|
b0dd25a82
|
1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 |
/** * 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. */ |
9796fdd82
|
1108 |
struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad385
|
1109 |
int type) |
1da177e4c
|
1110 1111 |
{ struct audit_buffer *ab = NULL; |
1da177e4c
|
1112 |
struct timespec t; |
ef00be055
|
1113 |
unsigned int uninitialized_var(serial); |
9ad9ad385
|
1114 |
int reserve; |
ac4cec443
|
1115 |
unsigned long timeout_start = jiffies; |
1da177e4c
|
1116 |
|
a3f07114e
|
1117 |
if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4c
|
1118 |
return NULL; |
c8edc80c8
|
1119 1120 |
if (unlikely(audit_filter_type(type))) return NULL; |
9ad9ad385
|
1121 1122 1123 |
if (gfp_mask & __GFP_WAIT) reserve = 0; else |
5600b8927
|
1124 |
reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad385
|
1125 1126 1127 1128 |
entries over the normal backlog limit */ while (audit_backlog_limit && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { |
ac4cec443
|
1129 1130 |
if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time && time_before(jiffies, timeout_start + audit_backlog_wait_time)) { |
9ad9ad385
|
1131 1132 1133 1134 1135 1136 1137 |
/* Wait for auditd to drain the queue a little */ DECLARE_WAITQUEUE(wait, current); set_current_state(TASK_INTERRUPTIBLE); add_wait_queue(&audit_backlog_wait, &wait); if (audit_backlog_limit && skb_queue_len(&audit_skb_queue) > audit_backlog_limit) |
ac4cec443
|
1138 |
schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies); |
9ad9ad385
|
1139 1140 1141 |
__set_current_state(TASK_RUNNING); remove_wait_queue(&audit_backlog_wait, &wait); |
ac4cec443
|
1142 |
continue; |
9ad9ad385
|
1143 |
} |
320f1b1ed
|
1144 |
if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6a
|
1145 1146 1147 1148 1149 1150 1151 |
printk(KERN_WARNING "audit: audit_backlog=%d > " "audit_backlog_limit=%d ", skb_queue_len(&audit_skb_queue), audit_backlog_limit); audit_log_lost("backlog limit exceeded"); |
ac4cec443
|
1152 1153 |
audit_backlog_wait_time = audit_backlog_wait_overflow; wake_up(&audit_backlog_wait); |
fb19b4c6a
|
1154 1155 |
return NULL; } |
9ad9ad385
|
1156 |
ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4c
|
1157 1158 1159 1160 |
if (!ab) { audit_log_lost("out of memory in audit_log_start"); return NULL; } |
bfb4496e7
|
1161 |
audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6a
|
1162 |
|
1da177e4c
|
1163 1164 1165 1166 |
audit_log_format(ab, "audit(%lu.%03lu:%u): ", t.tv_sec, t.tv_nsec/1000000, serial); return ab; } |
8fc6115c2
|
1167 |
/** |
5ac52f33b
|
1168 |
* audit_expand - expand skb in the audit buffer |
8fc6115c2
|
1169 |
* @ab: audit_buffer |
b0dd25a82
|
1170 |
* @extra: space to add at tail of the skb |
8fc6115c2
|
1171 1172 1173 1174 |
* * Returns 0 (no space) on failed expansion, or available space if * successful. */ |
e3b926b4c
|
1175 |
static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c2
|
1176 |
{ |
5ac52f33b
|
1177 |
struct sk_buff *skb = ab->skb; |
406a1d868
|
1178 1179 1180 |
int oldtail = skb_tailroom(skb); int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); int newtail = skb_tailroom(skb); |
5ac52f33b
|
1181 1182 |
if (ret < 0) { audit_log_lost("out of memory in audit_expand"); |
8fc6115c2
|
1183 |
return 0; |
5ac52f33b
|
1184 |
} |
406a1d868
|
1185 1186 1187 |
skb->truesize += newtail - oldtail; return newtail; |
8fc6115c2
|
1188 |
} |
1da177e4c
|
1189 |
|
b0dd25a82
|
1190 1191 |
/* * Format an audit message into the audit buffer. If there isn't enough |
1da177e4c
|
1192 1193 |
* room in the audit buffer, more room will be allocated and vsnprint * will be called a second time. Currently, we assume that a printk |
b0dd25a82
|
1194 1195 |
* can't format message larger than 1024 bytes, so we don't either. */ |
1da177e4c
|
1196 1197 1198 1199 |
static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, va_list args) { int len, avail; |
5ac52f33b
|
1200 |
struct sk_buff *skb; |
eecb0a733
|
1201 |
va_list args2; |
1da177e4c
|
1202 1203 1204 |
if (!ab) return; |
5ac52f33b
|
1205 1206 1207 1208 |
BUG_ON(!ab->skb); skb = ab->skb; avail = skb_tailroom(skb); if (avail == 0) { |
e3b926b4c
|
1209 |
avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c2
|
1210 1211 |
if (!avail) goto out; |
1da177e4c
|
1212 |
} |
eecb0a733
|
1213 |
va_copy(args2, args); |
27a884dc3
|
1214 |
len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4c
|
1215 1216 1217 1218 |
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. */ |
b0dd25a82
|
1219 1220 |
avail = audit_expand(ab, max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); |
8fc6115c2
|
1221 1222 |
if (!avail) goto out; |
27a884dc3
|
1223 |
len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4c
|
1224 |
} |
148b38dc9
|
1225 |
va_end(args2); |
168b71739
|
1226 1227 |
if (len > 0) skb_put(skb, len); |
8fc6115c2
|
1228 1229 |
out: return; |
1da177e4c
|
1230 |
} |
b0dd25a82
|
1231 1232 1233 1234 1235 1236 1237 1238 |
/** * 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. */ |
1da177e4c
|
1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 |
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); } |
b0dd25a82
|
1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 |
/** * audit_log_hex - convert a buffer to hex and append it to the audit skb * @ab: the audit_buffer * @buf: buffer to convert to hex * @len: length of @buf to be converted * * No return value; failure to expand is silently ignored. * * This function will take the passed buf and convert it into a string of * ascii hex digits. The new string is placed onto the skb. */ |
b556f8ad5
|
1260 |
void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b71739
|
1261 |
size_t len) |
83c7d0917
|
1262 |
{ |
168b71739
|
1263 1264 1265 1266 |
int i, avail, new_len; unsigned char *ptr; struct sk_buff *skb; static const unsigned char *hex = "0123456789ABCDEF"; |
8ef2d3040
|
1267 1268 |
if (!ab) return; |
168b71739
|
1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 |
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; } |
83c7d0917
|
1280 |
|
27a884dc3
|
1281 |
ptr = skb_tail_pointer(skb); |
168b71739
|
1282 1283 1284 1285 1286 1287 |
for (i=0; i<len; i++) { *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ } *ptr = 0; skb_put(skb, len << 1); /* new string is twice the old string */ |
83c7d0917
|
1288 |
} |
9c937dcc7
|
1289 1290 1291 1292 |
/* * Format a string of no more than slen characters into the audit buffer, * enclosed in quote marks. */ |
b556f8ad5
|
1293 1294 |
void audit_log_n_string(struct audit_buffer *ab, const char *string, size_t slen) |
9c937dcc7
|
1295 1296 1297 1298 |
{ int avail, new_len; unsigned char *ptr; struct sk_buff *skb; |
8ef2d3040
|
1299 1300 |
if (!ab) return; |
9c937dcc7
|
1301 1302 1303 1304 1305 1306 1307 1308 1309 |
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; } |
27a884dc3
|
1310 |
ptr = skb_tail_pointer(skb); |
9c937dcc7
|
1311 1312 1313 1314 1315 1316 1317 |
*ptr++ = '"'; memcpy(ptr, string, slen); ptr += slen; *ptr++ = '"'; *ptr = 0; skb_put(skb, slen + 2); /* don't include null terminator */ } |
b0dd25a82
|
1318 |
/** |
de6bbd1d3
|
1319 |
* audit_string_contains_control - does a string need to be logged in hex |
f706d5d22
|
1320 1321 |
* @string: string to be checked * @len: max length of the string to check |
de6bbd1d3
|
1322 1323 1324 1325 |
*/ int audit_string_contains_control(const char *string, size_t len) { const unsigned char *p; |
b3897f567
|
1326 |
for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649e
|
1327 |
if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d3
|
1328 1329 1330 1331 1332 1333 |
return 1; } return 0; } /** |
522ed7767
|
1334 |
* audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a82
|
1335 |
* @ab: audit_buffer |
f706d5d22
|
1336 |
* @len: length of string (not including trailing null) |
b0dd25a82
|
1337 1338 1339 1340 |
* @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, |
168b71739
|
1341 |
* or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a82
|
1342 |
* Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc7
|
1343 1344 1345 |
* * The caller specifies the number of characters in the string to log, which may * or may not be the entire string. |
b0dd25a82
|
1346 |
*/ |
b556f8ad5
|
1347 1348 |
void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, size_t len) |
83c7d0917
|
1349 |
{ |
de6bbd1d3
|
1350 |
if (audit_string_contains_control(string, len)) |
b556f8ad5
|
1351 |
audit_log_n_hex(ab, string, len); |
de6bbd1d3
|
1352 |
else |
b556f8ad5
|
1353 |
audit_log_n_string(ab, string, len); |
83c7d0917
|
1354 |
} |
9c937dcc7
|
1355 |
/** |
522ed7767
|
1356 |
* audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc7
|
1357 1358 1359 |
* @ab: audit_buffer * @string: string to be logged * |
522ed7767
|
1360 |
* Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc7
|
1361 1362 |
* determine string length. */ |
de6bbd1d3
|
1363 |
void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc7
|
1364 |
{ |
b556f8ad5
|
1365 |
audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc7
|
1366 |
} |
168b71739
|
1367 |
/* This is a helper-function to print the escaped d_path */ |
1da177e4c
|
1368 |
void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
44707fdf5
|
1369 |
struct path *path) |
1da177e4c
|
1370 |
{ |
44707fdf5
|
1371 |
char *p, *pathname; |
1da177e4c
|
1372 |
|
8fc6115c2
|
1373 1374 |
if (prefix) audit_log_format(ab, " %s", prefix); |
1da177e4c
|
1375 |
|
168b71739
|
1376 |
/* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf5
|
1377 1378 |
pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); if (!pathname) { |
def575434
|
1379 |
audit_log_string(ab, "<no_memory>"); |
168b71739
|
1380 |
return; |
1da177e4c
|
1381 |
} |
cf28b4863
|
1382 |
p = d_path(path, pathname, PATH_MAX+11); |
168b71739
|
1383 1384 |
if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ /* FIXME: can we save some information here? */ |
def575434
|
1385 |
audit_log_string(ab, "<too_long>"); |
5600b8927
|
1386 |
} else |
168b71739
|
1387 |
audit_log_untrustedstring(ab, p); |
44707fdf5
|
1388 |
kfree(pathname); |
1da177e4c
|
1389 |
} |
9d9609851
|
1390 1391 1392 1393 1394 1395 1396 1397 |
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)"); } |
b0dd25a82
|
1398 1399 1400 1401 1402 1403 |
/** * audit_log_end - end one audit record * @ab: the audit_buffer * * The netlink_* functions cannot be called inside an irq context, so * the audit buffer is placed on a queue and a tasklet is scheduled to |
1da177e4c
|
1404 |
* remove them from the queue outside the irq context. May be called in |
b0dd25a82
|
1405 1406 |
* any context. */ |
b7d112581
|
1407 |
void audit_log_end(struct audit_buffer *ab) |
1da177e4c
|
1408 |
{ |
1da177e4c
|
1409 1410 1411 1412 1413 |
if (!ab) return; if (!audit_rate_check()) { audit_log_lost("rate limit exceeded"); } else { |
8d07a67cf
|
1414 |
struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
f3d357b09
|
1415 |
nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); |
b7d112581
|
1416 |
if (audit_pid) { |
b7d112581
|
1417 |
skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d112581
|
1418 |
wake_up_interruptible(&kauditd_wait); |
f3d357b09
|
1419 |
} else { |
038cbcf65
|
1420 |
audit_printk_skb(ab->skb); |
b7d112581
|
1421 |
} |
f3d357b09
|
1422 |
ab->skb = NULL; |
1da177e4c
|
1423 |
} |
16e1904e6
|
1424 |
audit_buffer_free(ab); |
1da177e4c
|
1425 |
} |
b0dd25a82
|
1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 |
/** * 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. */ |
5600b8927
|
1438 |
void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad385
|
1439 |
const char *fmt, ...) |
1da177e4c
|
1440 1441 1442 |
{ struct audit_buffer *ab; va_list args; |
9ad9ad385
|
1443 |
ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4c
|
1444 1445 1446 1447 1448 1449 1450 |
if (ab) { va_start(args, fmt); audit_log_vformat(ab, fmt, args); va_end(args); audit_log_end(ab); } } |
bf45da97a
|
1451 1452 1453 1454 1455 |
EXPORT_SYMBOL(audit_log_start); EXPORT_SYMBOL(audit_log_end); EXPORT_SYMBOL(audit_log_format); EXPORT_SYMBOL(audit_log); |