| 1 | |
| 2 | * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
|
| 3 | * System-call specific features have moved to auditsc.c
|
| 4 | *
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| 5 | * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
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| 6 | * All Rights Reserved.
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| 7 | *
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| 8 | * This program is free software; you can redistribute it and/or modify
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| 9 | * it under the terms of the GNU General Public License as published by
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| 10 | * the Free Software Foundation; either version 2 of the License, or
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| 11 | * (at your option) any later version.
|
| 12 | *
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| 13 | * This program is distributed in the hope that it will be useful,
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| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 16 | * GNU General Public License for more details.
|
| 17 | *
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| 18 | * You should have received a copy of the GNU General Public License
|
| 19 | * along with this program; if not, write to the Free Software
|
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
| 21 | *
|
| 22 | * Written by Rickard E. (Rik) Faith <[email protected]>
|
| 23 | *
|
| 24 | * Goals: 1) Integrate fully with Security Modules.
|
| 25 | * 2) Minimal run-time overhead:
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| 26 | * a) Minimal when syscall auditing is disabled (audit_enable=0).
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| 27 | * b) Small when syscall auditing is enabled and no audit record
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| 28 | * is generated (defer as much work as possible to record
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| 29 | * generation time):
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| 30 | * i) context is allocated,
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| 31 | * ii) names from getname are stored without a copy, and
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| 32 | * iii) inode information stored from path_lookup.
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| 33 | * 3) Ability to disable syscall auditing at boot time (audit=0).
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| 34 | * 4) Usable by other parts of the kernel (if audit_log* is called,
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| 35 | * then a syscall record will be generated automatically for the
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| 36 | * current syscall).
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| 37 | * 5) Netlink interface to user-space.
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| 38 | * 6) Support low-overhead kernel-based filtering to minimize the
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| 39 | * information that must be passed to user-space.
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| 40 | *
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| 41 | * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
|
| 42 |
|
| 43 |
|
| 44 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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| 45 |
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| 46 | #include <linux/file.h>
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| 47 | #include <linux/init.h>
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| 48 | #include <linux/types.h>
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| 49 | #include <linux/atomic.h>
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| 50 | #include <linux/mm.h>
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| 51 | #include <linux/export.h>
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| 52 | #include <linux/slab.h>
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| 53 | #include <linux/err.h>
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| 54 | #include <linux/kthread.h>
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| 55 | #include <linux/kernel.h>
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| 56 | #include <linux/syscalls.h>
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| 57 | #include <linux/spinlock.h>
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| 58 | #include <linux/rcupdate.h>
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| 59 | #include <linux/mutex.h>
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| 60 | #include <linux/gfp.h>
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| 61 | #include <linux/pid.h>
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| 62 | #include <linux/slab.h>
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| 63 |
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| 64 | #include <linux/audit.h>
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| 65 |
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| 66 | #include <net/sock.h>
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| 67 | #include <net/netlink.h>
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| 68 | #include <linux/skbuff.h>
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| 69 | #ifdef CONFIG_SECURITY
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| 70 | #include <linux/security.h>
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| 71 | #endif
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| 72 | #include <linux/freezer.h>
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| 73 | #include <linux/pid_namespace.h>
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| 74 | #include <net/netns/generic.h>
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| 75 |
|
| 76 | #include "audit.h"
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| 77 |
|
| 78 | |
| 79 | * (Initialization happens after skb_init is called.)
|
| 80 | #define AUDIT_DISABLED -1
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| 81 | #define AUDIT_UNINITIALIZED 0
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| 82 | #define AUDIT_INITIALIZED 1
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| 83 | static int audit_initialized;
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| 84 |
|
| 85 | #define AUDIT_OFF 0
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| 86 | #define AUDIT_ON 1
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| 87 | #define AUDIT_LOCKED 2
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| 88 | u32 audit_enabled;
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| 89 | u32 audit_ever_enabled;
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| 90 |
|
| 91 | EXPORT_SYMBOL_GPL(audit_enabled);
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| 92 |
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| 93 |
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| 94 | static u32 audit_default;
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| 95 |
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| 96 |
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| 97 | static u32 audit_failure = AUDIT_FAIL_PRINTK;
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| 98 |
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| 99 |
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| 100 | static unsigned int audit_net_id;
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| 101 |
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| 102 | |
| 103 | * struct audit_net - audit private network namespace data
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| 104 | * @sk: communication socket
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| 105 |
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| 106 | struct audit_net {
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| 107 | struct sock *sk;
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| 108 | };
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| 109 |
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| 110 | |
| 111 | * struct auditd_connection - kernel/auditd connection state
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| 112 | * @pid: auditd PID
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| 113 | * @portid: netlink portid
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| 114 | * @net: the associated network namespace
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| 115 | * @rcu: RCU head
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| 116 | *
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| 117 | * Description:
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| 118 | * This struct is RCU protected; you must either hold the RCU lock for reading
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| 119 | * or the associated spinlock for writing.
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| 120 |
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| 121 | static struct auditd_connection {
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| 122 | struct pid *pid;
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| 123 | u32 portid;
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| 124 | struct net *net;
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| 125 | struct rcu_head rcu;
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| 126 | } *auditd_conn = NULL;
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| 127 | static DEFINE_SPINLOCK(auditd_conn_lock);
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| 128 |
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| 129 | |
| 130 | * to that number per second. This prevents DoS attacks, but results in
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| 131 | * audit records being dropped.
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| 132 | static u32 audit_rate_limit;
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| 133 |
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| 134 | |
| 135 | * When set to zero, this means unlimited.
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| 136 | static u32 audit_backlog_limit = 64;
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| 137 | #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
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| 138 | static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
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| 139 |
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| 140 |
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| 141 | kuid_t audit_sig_uid = INVALID_UID;
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| 142 | pid_t audit_sig_pid = -1;
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| 143 | u32 audit_sig_sid = 0;
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| 144 |
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| 145 | |
| 146 | 0) [suppressed in audit_alloc]
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| 147 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
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| 148 | 2) out of memory in audit_log_move [alloc_skb]
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| 149 | 3) suppressed due to audit_rate_limit
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| 150 | 4) suppressed due to audit_backlog_limit
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| 151 |
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| 152 | static atomic_t audit_lost = ATOMIC_INIT(0);
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| 153 |
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| 154 |
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| 155 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
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| 156 |
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| 157 | static struct kmem_cache *audit_buffer_cache;
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| 158 |
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| 159 |
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| 160 | static struct sk_buff_head audit_queue;
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| 161 |
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| 162 | static struct sk_buff_head audit_retry_queue;
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| 163 |
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| 164 | static struct sk_buff_head audit_hold_queue;
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| 165 |
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| 166 |
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| 167 | static struct task_struct *kauditd_task;
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| 168 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
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| 169 |
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| 170 |
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| 171 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
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| 172 |
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| 173 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
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| 174 | .mask = -1,
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| 175 | .features = 0,
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| 176 | .lock = 0,};
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| 177 |
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| 178 | static char *audit_feature_names[2] = {
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| 179 | "only_unset_loginuid",
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| 180 | "loginuid_immutable",
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| 181 | };
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| 182 |
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| 183 |
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| 184 |
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| 185 | DEFINE_MUTEX(audit_cmd_mutex);
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| 186 |
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| 187 | |
| 188 | * audit records. Since printk uses a 1024 byte buffer, this buffer
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| 189 | * should be at least that large.
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| 190 | #define AUDIT_BUFSIZ 1024
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| 191 |
|
| 192 | |
| 193 | * locks briefly to get the record off the freelist or to allocate the
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| 194 | * buffer, and locks briefly to send the buffer to the netlink layer or
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| 195 | * to place it on a transmit queue. Multiple audit_buffers can be in
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| 196 | * use simultaneously.
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| 197 | struct audit_buffer {
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| 198 | struct sk_buff *skb;
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| 199 | struct audit_context *ctx;
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| 200 | gfp_t gfp_mask;
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| 201 | };
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| 202 |
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| 203 | struct audit_reply {
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| 204 | __u32 portid;
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| 205 | struct net *net;
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| 206 | struct sk_buff *skb;
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| 207 | };
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| 208 |
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| 209 | |
| 210 | * auditd_test_task - Check to see if a given task is an audit daemon
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| 211 | * @task: the task to check
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| 212 | *
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| 213 | * Description:
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| 214 | * Return 1 if the task is a registered audit daemon, 0 otherwise.
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| 215 |
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| 216 | int auditd_test_task(struct task_struct *task)
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| 217 | {
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| 218 | int rc;
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| 219 | struct auditd_connection *ac;
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| 220 |
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| 221 | rcu_read_lock();
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| 222 | ac = rcu_dereference(auditd_conn);
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| 223 | rc = (ac && ac->pid == task_tgid(task) ? 1 : 0);
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| 224 | rcu_read_unlock();
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| 225 |
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| 226 | return rc;
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| 227 | }
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| 228 |
|
| 229 | |
| 230 | * auditd_pid_vnr - Return the auditd PID relative to the namespace
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| 231 | *
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| 232 | * Description:
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| 233 | * Returns the PID in relation to the namespace, 0 on failure.
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| 234 |
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| 235 | static pid_t auditd_pid_vnr(void)
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| 236 | {
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| 237 | pid_t pid;
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| 238 | const struct auditd_connection *ac;
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| 239 |
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| 240 | rcu_read_lock();
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| 241 | ac = rcu_dereference(auditd_conn);
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| 242 | if (!ac || !ac->pid)
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| 243 | pid = 0;
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| 244 | else
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| 245 | pid = pid_vnr(ac->pid);
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| 246 | rcu_read_unlock();
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| 247 |
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| 248 | return pid;
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| 249 | }
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| 250 |
|
| 251 | |
| 252 | * audit_get_sk - Return the audit socket for the given network namespace
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| 253 | * @net: the destination network namespace
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| 254 | *
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| 255 | * Description:
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| 256 | * Returns the sock pointer if valid, NULL otherwise. The caller must ensure
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| 257 | * that a reference is held for the network namespace while the sock is in use.
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| 258 |
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| 259 | static struct sock *audit_get_sk(const struct net *net)
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| 260 | {
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| 261 | struct audit_net *aunet;
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| 262 |
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| 263 | if (!net)
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| 264 | return NULL;
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| 265 |
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| 266 | aunet = net_generic(net, audit_net_id);
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| 267 | return aunet->sk;
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| 268 | }
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| 269 |
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| 270 | void audit_panic(const char *message)
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| 271 | {
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| 272 | switch (audit_failure) {
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| 273 | case AUDIT_FAIL_SILENT:
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| 274 | break;
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| 275 | case AUDIT_FAIL_PRINTK:
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| 276 | if (printk_ratelimit())
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| 277 | pr_err("%s\n", message);
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| 278 | break;
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| 279 | case AUDIT_FAIL_PANIC:
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| 280 | panic("audit: %s\n", message);
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| 281 | break;
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| 282 | }
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| 283 | }
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| 284 |
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| 285 | static inline int audit_rate_check(void)
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| 286 | {
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| 287 | static unsigned long last_check = 0;
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| 288 | static int messages = 0;
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| 289 | static DEFINE_SPINLOCK(lock);
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| 290 | unsigned long flags;
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| 291 | unsigned long now;
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| 292 | unsigned long elapsed;
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| 293 | int retval = 0;
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| 294 |
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| 295 | if (!audit_rate_limit) return 1;
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| 296 |
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| 297 | spin_lock_irqsave(&lock, flags);
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| 298 | if (++messages < audit_rate_limit) {
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| 299 | retval = 1;
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| 300 | } else {
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| 301 | now = jiffies;
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| 302 | elapsed = now - last_check;
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| 303 | if (elapsed > HZ) {
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| 304 | last_check = now;
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| 305 | messages = 0;
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| 306 | retval = 1;
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| 307 | }
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| 308 | }
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| 309 | spin_unlock_irqrestore(&lock, flags);
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| 310 |
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| 311 | return retval;
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| 312 | }
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| 313 |
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| 314 | |
| 315 | * audit_log_lost - conditionally log lost audit message event
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| 316 | * @message: the message stating reason for lost audit message
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| 317 | *
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| 318 | * Emit at least 1 message per second, even if audit_rate_check is
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| 319 | * throttling.
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| 320 | * Always increment the lost messages counter.
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| 321 |
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| 322 | void audit_log_lost(const char *message)
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| 323 | {
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| 324 | static unsigned long last_msg = 0;
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| 325 | static DEFINE_SPINLOCK(lock);
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| 326 | unsigned long flags;
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| 327 | unsigned long now;
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| 328 | int print;
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| 329 |
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| 330 | atomic_inc(&audit_lost);
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| 331 |
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| 332 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
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| 333 |
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| 334 | if (!print) {
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| 335 | spin_lock_irqsave(&lock, flags);
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| 336 | now = jiffies;
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| 337 | if (now - last_msg > HZ) {
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| 338 | print = 1;
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| 339 | last_msg = now;
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| 340 | }
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| 341 | spin_unlock_irqrestore(&lock, flags);
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| 342 | }
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| 343 |
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| 344 | if (print) {
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| 345 | if (printk_ratelimit())
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| 346 | pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
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| 347 | atomic_read(&audit_lost),
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| 348 | audit_rate_limit,
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| 349 | audit_backlog_limit);
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| 350 | audit_panic(message);
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| 351 | }
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| 352 | }
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| 353 |
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| 354 | static int audit_log_config_change(char *function_name, u32 new, u32 old,
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| 355 | int allow_changes)
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| 356 | {
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| 357 | struct audit_buffer *ab;
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| 358 | int rc = 0;
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| 359 |
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| 360 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
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| 361 | if (unlikely(!ab))
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| 362 | return rc;
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| 363 | audit_log_format(ab, "%s=%u old=%u", function_name, new, old);
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| 364 | audit_log_session_info(ab);
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| 365 | rc = audit_log_task_context(ab);
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| 366 | if (rc)
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| 367 | allow_changes = 0;
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| 368 | audit_log_format(ab, " res=%d", allow_changes);
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| 369 | audit_log_end(ab);
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| 370 | return rc;
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| 371 | }
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| 372 |
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| 373 | static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
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| 374 | {
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| 375 | int allow_changes, rc = 0;
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| 376 | u32 old = *to_change;
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| 377 |
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| 378 |
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| 379 | if (audit_enabled == AUDIT_LOCKED)
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| 380 | allow_changes = 0;
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| 381 | else
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| 382 | allow_changes = 1;
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| 383 |
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| 384 | if (audit_enabled != AUDIT_OFF) {
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| 385 | rc = audit_log_config_change(function_name, new, old, allow_changes);
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| 386 | if (rc)
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| 387 | allow_changes = 0;
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| 388 | }
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| 389 |
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| 390 |
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| 391 | if (allow_changes == 1)
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| 392 | *to_change = new;
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| 393 |
|
| 394 | else if (rc == 0)
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| 395 | rc = -EPERM;
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| 396 | return rc;
|
| 397 | }
|
| 398 |
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| 399 | static int audit_set_rate_limit(u32 limit)
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| 400 | {
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| 401 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
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| 402 | }
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| 403 |
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| 404 | static int audit_set_backlog_limit(u32 limit)
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| 405 | {
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| 406 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
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| 407 | }
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| 408 |
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| 409 | static int audit_set_backlog_wait_time(u32 timeout)
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| 410 | {
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| 411 | return audit_do_config_change("audit_backlog_wait_time",
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| 412 | &audit_backlog_wait_time, timeout);
|
| 413 | }
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| 414 |
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| 415 | static int audit_set_enabled(u32 state)
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| 416 | {
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| 417 | int rc;
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| 418 | if (state > AUDIT_LOCKED)
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| 419 | return -EINVAL;
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| 420 |
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| 421 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
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| 422 | if (!rc)
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| 423 | audit_ever_enabled |= !!state;
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| 424 |
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| 425 | return rc;
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| 426 | }
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| 427 |
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| 428 | static int audit_set_failure(u32 state)
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| 429 | {
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| 430 | if (state != AUDIT_FAIL_SILENT
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| 431 | && state != AUDIT_FAIL_PRINTK
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| 432 | && state != AUDIT_FAIL_PANIC)
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| 433 | return -EINVAL;
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| 434 |
|
| 435 | return audit_do_config_change("audit_failure", &audit_failure, state);
|
| 436 | }
|
| 437 |
|
| 438 | |
| 439 | * auditd_conn_free - RCU helper to release an auditd connection struct
|
| 440 | * @rcu: RCU head
|
| 441 | *
|
| 442 | * Description:
|
| 443 | * Drop any references inside the auditd connection tracking struct and free
|
| 444 | * the memory.
|
| 445 |
|
| 446 | static void auditd_conn_free(struct rcu_head *rcu)
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| 447 | {
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| 448 | struct auditd_connection *ac;
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| 449 |
|
| 450 | ac = container_of(rcu, struct auditd_connection, rcu);
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| 451 | put_pid(ac->pid);
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| 452 | put_net(ac->net);
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| 453 | kfree(ac);
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| 454 | }
|
| 455 |
|
| 456 | |
| 457 | * auditd_set - Set/Reset the auditd connection state
|
| 458 | * @pid: auditd PID
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| 459 | * @portid: auditd netlink portid
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| 460 | * @net: auditd network namespace pointer
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| 461 | *
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| 462 | * Description:
|
| 463 | * This function will obtain and drop network namespace references as
|
| 464 | * necessary. Returns zero on success, negative values on failure.
|
| 465 |
|
| 466 | static int auditd_set(struct pid *pid, u32 portid, struct net *net)
|
| 467 | {
|
| 468 | unsigned long flags;
|
| 469 | struct auditd_connection *ac_old, *ac_new;
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| 470 |
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| 471 | if (!pid || !net)
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| 472 | return -EINVAL;
|
| 473 |
|
| 474 | ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL);
|
| 475 | if (!ac_new)
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| 476 | return -ENOMEM;
|
| 477 | ac_new->pid = get_pid(pid);
|
| 478 | ac_new->portid = portid;
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| 479 | ac_new->net = get_net(net);
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| 480 |
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| 481 | spin_lock_irqsave(&auditd_conn_lock, flags);
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| 482 | ac_old = rcu_dereference_protected(auditd_conn,
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| 483 | lockdep_is_held(&auditd_conn_lock));
|
| 484 | rcu_assign_pointer(auditd_conn, ac_new);
|
| 485 | spin_unlock_irqrestore(&auditd_conn_lock, flags);
|
| 486 |
|
| 487 | if (ac_old)
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| 488 | call_rcu(&ac_old->rcu, auditd_conn_free);
|
| 489 |
|
| 490 | return 0;
|
| 491 | }
|
| 492 |
|
| 493 | |
| 494 | * kauditd_print_skb - Print the audit record to the ring buffer
|
| 495 | * @skb: audit record
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| 496 | *
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| 497 | * Whatever the reason, this packet may not make it to the auditd connection
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| 498 | * so write it via printk so the information isn't completely lost.
|
| 499 |
|
| 500 | static void kauditd_printk_skb(struct sk_buff *skb)
|
| 501 | {
|
| 502 | struct nlmsghdr *nlh = nlmsg_hdr(skb);
|
| 503 | char *data = nlmsg_data(nlh);
|
| 504 |
|
| 505 | if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit())
|
| 506 | pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
|
| 507 | }
|
| 508 |
|
| 509 | |
| 510 | * kauditd_rehold_skb - Handle a audit record send failure in the hold queue
|
| 511 | * @skb: audit record
|
| 512 | *
|
| 513 | * Description:
|
| 514 | * This should only be used by the kauditd_thread when it fails to flush the
|
| 515 | * hold queue.
|
| 516 |
|
| 517 | static void kauditd_rehold_skb(struct sk_buff *skb)
|
| 518 | {
|
| 519 |
|
| 520 | skb_queue_head(&audit_hold_queue, skb);
|
| 521 | }
|
| 522 |
|
| 523 | |
| 524 | * kauditd_hold_skb - Queue an audit record, waiting for auditd
|
| 525 | * @skb: audit record
|
| 526 | *
|
| 527 | * Description:
|
| 528 | * Queue the audit record, waiting for an instance of auditd. When this
|
| 529 | * function is called we haven't given up yet on sending the record, but things
|
| 530 | * are not looking good. The first thing we want to do is try to write the
|
| 531 | * record via printk and then see if we want to try and hold on to the record
|
| 532 | * and queue it, if we have room. If we want to hold on to the record, but we
|
| 533 | * don't have room, record a record lost message.
|
| 534 |
|
| 535 | static void kauditd_hold_skb(struct sk_buff *skb)
|
| 536 | {
|
| 537 | |
| 538 | * try to send the message via printk before we go any further
|
| 539 | kauditd_printk_skb(skb);
|
| 540 |
|
| 541 |
|
| 542 | if (!audit_default) {
|
| 543 | kfree_skb(skb);
|
| 544 | return;
|
| 545 | }
|
| 546 |
|
| 547 |
|
| 548 | if (!audit_backlog_limit ||
|
| 549 | skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
|
| 550 | skb_queue_tail(&audit_hold_queue, skb);
|
| 551 | return;
|
| 552 | }
|
| 553 |
|
| 554 |
|
| 555 | audit_log_lost("kauditd hold queue overflow");
|
| 556 | kfree_skb(skb);
|
| 557 | }
|
| 558 |
|
| 559 | |
| 560 | * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
|
| 561 | * @skb: audit record
|
| 562 | *
|
| 563 | * Description:
|
| 564 | * Not as serious as kauditd_hold_skb() as we still have a connected auditd,
|
| 565 | * but for some reason we are having problems sending it audit records so
|
| 566 | * queue the given record and attempt to resend.
|
| 567 |
|
| 568 | static void kauditd_retry_skb(struct sk_buff *skb)
|
| 569 | {
|
| 570 | |
| 571 | * short period of time, before either being sent or moved to the hold
|
| 572 | * queue, we don't currently enforce a limit on this queue
|
| 573 | skb_queue_tail(&audit_retry_queue, skb);
|
| 574 | }
|
| 575 |
|
| 576 | |
| 577 | * auditd_reset - Disconnect the auditd connection
|
| 578 | *
|
| 579 | * Description:
|
| 580 | * Break the auditd/kauditd connection and move all the queued records into the
|
| 581 | * hold queue in case auditd reconnects.
|
| 582 |
|
| 583 | static void auditd_reset(void)
|
| 584 | {
|
| 585 | unsigned long flags;
|
| 586 | struct sk_buff *skb;
|
| 587 | struct auditd_connection *ac_old;
|
| 588 |
|
| 589 |
|
| 590 | spin_lock_irqsave(&auditd_conn_lock, flags);
|
| 591 | ac_old = rcu_dereference_protected(auditd_conn,
|
| 592 | lockdep_is_held(&auditd_conn_lock));
|
| 593 | rcu_assign_pointer(auditd_conn, NULL);
|
| 594 | spin_unlock_irqrestore(&auditd_conn_lock, flags);
|
| 595 |
|
| 596 | if (ac_old)
|
| 597 | call_rcu(&ac_old->rcu, auditd_conn_free);
|
| 598 |
|
| 599 |
|
| 600 | while ((skb = skb_dequeue(&audit_retry_queue)))
|
| 601 | kauditd_hold_skb(skb);
|
| 602 | while ((skb = skb_dequeue(&audit_queue)))
|
| 603 | kauditd_hold_skb(skb);
|
| 604 | }
|
| 605 |
|
| 606 | |
| 607 | * auditd_send_unicast_skb - Send a record via unicast to auditd
|
| 608 | * @skb: audit record
|
| 609 | *
|
| 610 | * Description:
|
| 611 | * Send a skb to the audit daemon, returns positive/zero values on success and
|
| 612 | * negative values on failure; in all cases the skb will be consumed by this
|
| 613 | * function. If the send results in -ECONNREFUSED the connection with auditd
|
| 614 | * will be reset. This function may sleep so callers should not hold any locks
|
| 615 | * where this would cause a problem.
|
| 616 |
|
| 617 | static int auditd_send_unicast_skb(struct sk_buff *skb)
|
| 618 | {
|
| 619 | int rc;
|
| 620 | u32 portid;
|
| 621 | struct net *net;
|
| 622 | struct sock *sk;
|
| 623 | struct auditd_connection *ac;
|
| 624 |
|
| 625 | |
| 626 | * take a reference to the network namespace and grab local
|
| 627 | * copies of the namespace, the sock, and the portid; the
|
| 628 | * namespace and sock aren't going to go away while we hold a
|
| 629 | * reference and if the portid does become invalid after the RCU
|
| 630 | * section netlink_unicast() should safely return an error
|
| 631 |
|
| 632 | rcu_read_lock();
|
| 633 | ac = rcu_dereference(auditd_conn);
|
| 634 | if (!ac) {
|
| 635 | rcu_read_unlock();
|
| 636 | rc = -ECONNREFUSED;
|
| 637 | goto err;
|
| 638 | }
|
| 639 | net = get_net(ac->net);
|
| 640 | sk = audit_get_sk(net);
|
| 641 | portid = ac->portid;
|
| 642 | rcu_read_unlock();
|
| 643 |
|
| 644 | rc = netlink_unicast(sk, skb, portid, 0);
|
| 645 | put_net(net);
|
| 646 | if (rc < 0)
|
| 647 | goto err;
|
| 648 |
|
| 649 | return rc;
|
| 650 |
|
| 651 | err:
|
| 652 | if (rc == -ECONNREFUSED)
|
| 653 | auditd_reset();
|
| 654 | return rc;
|
| 655 | }
|
| 656 |
|
| 657 | |
| 658 | * kauditd_send_queue - Helper for kauditd_thread to flush skb queues
|
| 659 | * @sk: the sending sock
|
| 660 | * @portid: the netlink destination
|
| 661 | * @queue: the skb queue to process
|
| 662 | * @retry_limit: limit on number of netlink unicast failures
|
| 663 | * @skb_hook: per-skb hook for additional processing
|
| 664 | * @err_hook: hook called if the skb fails the netlink unicast send
|
| 665 | *
|
| 666 | * Description:
|
| 667 | * Run through the given queue and attempt to send the audit records to auditd,
|
| 668 | * returns zero on success, negative values on failure. It is up to the caller
|
| 669 | * to ensure that the @sk is valid for the duration of this function.
|
| 670 | *
|
| 671 |
|
| 672 | static int kauditd_send_queue(struct sock *sk, u32 portid,
|
| 673 | struct sk_buff_head *queue,
|
| 674 | unsigned int retry_limit,
|
| 675 | void (*skb_hook)(struct sk_buff *skb),
|
| 676 | void (*err_hook)(struct sk_buff *skb))
|
| 677 | {
|
| 678 | int rc = 0;
|
| 679 | struct sk_buff *skb;
|
| 680 | static unsigned int failed = 0;
|
| 681 |
|
| 682 | |
| 683 | * the netlink info passed to us (e.g. sk and portid)
|
| 684 |
|
| 685 | while ((skb = skb_dequeue(queue))) {
|
| 686 |
|
| 687 | if (skb_hook)
|
| 688 | (*skb_hook)(skb);
|
| 689 |
|
| 690 |
|
| 691 | if (!sk) {
|
| 692 | if (err_hook)
|
| 693 | (*err_hook)(skb);
|
| 694 | continue;
|
| 695 | }
|
| 696 |
|
| 697 |
|
| 698 | skb_get(skb);
|
| 699 | rc = netlink_unicast(sk, skb, portid, 0);
|
| 700 | if (rc < 0) {
|
| 701 |
|
| 702 | if (++failed >= retry_limit ||
|
| 703 | rc == -ECONNREFUSED || rc == -EPERM) {
|
| 704 |
|
| 705 | sk = NULL;
|
| 706 | if (err_hook)
|
| 707 | (*err_hook)(skb);
|
| 708 | if (!skb_hook)
|
| 709 | goto out;
|
| 710 |
|
| 711 | continue;
|
| 712 | } else
|
| 713 |
|
| 714 | skb_queue_head(queue, skb);
|
| 715 | } else {
|
| 716 |
|
| 717 | consume_skb(skb);
|
| 718 | failed = 0;
|
| 719 | }
|
| 720 | }
|
| 721 |
|
| 722 | out:
|
| 723 | return (rc >= 0 ? 0 : rc);
|
| 724 | }
|
| 725 |
|
| 726 | |
| 727 | * kauditd_send_multicast_skb - Send a record to any multicast listeners
|
| 728 | * @skb: audit record
|
| 729 | *
|
| 730 | * Description:
|
| 731 | * Write a multicast message to anyone listening in the initial network
|
| 732 | * namespace. This function doesn't consume an skb as might be expected since
|
| 733 | * it has to copy it anyways.
|
| 734 |
|
| 735 | static void kauditd_send_multicast_skb(struct sk_buff *skb)
|
| 736 | {
|
| 737 | struct sk_buff *copy;
|
| 738 | struct sock *sock = audit_get_sk(&init_net);
|
| 739 | struct nlmsghdr *nlh;
|
| 740 |
|
| 741 | |
| 742 | * we don't have to worry about it going away
|
| 743 |
|
| 744 | if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
|
| 745 | return;
|
| 746 |
|
| 747 | |
| 748 | * The seemingly wasteful skb_copy() rather than bumping the refcount
|
| 749 | * using skb_get() is necessary because non-standard mods are made to
|
| 750 | * the skb by the original kaudit unicast socket send routine. The
|
| 751 | * existing auditd daemon assumes this breakage. Fixing this would
|
| 752 | * require co-ordinating a change in the established protocol between
|
| 753 | * the kaudit kernel subsystem and the auditd userspace code. There is
|
| 754 | * no reason for new multicast clients to continue with this
|
| 755 | * non-compliance.
|
| 756 |
|
| 757 | copy = skb_copy(skb, GFP_KERNEL);
|
| 758 | if (!copy)
|
| 759 | return;
|
| 760 | nlh = nlmsg_hdr(copy);
|
| 761 | nlh->nlmsg_len = skb->len;
|
| 762 |
|
| 763 | nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
|
| 764 | }
|
| 765 |
|
| 766 | |
| 767 | * kauditd_thread - Worker thread to send audit records to userspace
|
| 768 | * @dummy: unused
|
| 769 |
|
| 770 | static int kauditd_thread(void *dummy)
|
| 771 | {
|
| 772 | int rc;
|
| 773 | u32 portid = 0;
|
| 774 | struct net *net = NULL;
|
| 775 | struct sock *sk = NULL;
|
| 776 | struct auditd_connection *ac;
|
| 777 |
|
| 778 | #define UNICAST_RETRIES 5
|
| 779 |
|
| 780 | set_freezable();
|
| 781 | while (!kthread_should_stop()) {
|
| 782 |
|
| 783 | rcu_read_lock();
|
| 784 | ac = rcu_dereference(auditd_conn);
|
| 785 | if (!ac) {
|
| 786 | rcu_read_unlock();
|
| 787 | goto main_queue;
|
| 788 | }
|
| 789 | net = get_net(ac->net);
|
| 790 | sk = audit_get_sk(net);
|
| 791 | portid = ac->portid;
|
| 792 | rcu_read_unlock();
|
| 793 |
|
| 794 |
|
| 795 | rc = kauditd_send_queue(sk, portid,
|
| 796 | &audit_hold_queue, UNICAST_RETRIES,
|
| 797 | NULL, kauditd_rehold_skb);
|
| 798 | if (rc < 0) {
|
| 799 | sk = NULL;
|
| 800 | auditd_reset();
|
| 801 | goto main_queue;
|
| 802 | }
|
| 803 |
|
| 804 |
|
| 805 | rc = kauditd_send_queue(sk, portid,
|
| 806 | &audit_retry_queue, UNICAST_RETRIES,
|
| 807 | NULL, kauditd_hold_skb);
|
| 808 | if (rc < 0) {
|
| 809 | sk = NULL;
|
| 810 | auditd_reset();
|
| 811 | goto main_queue;
|
| 812 | }
|
| 813 |
|
| 814 | main_queue:
|
| 815 | |
| 816 | * unicast, dump failed record sends to the retry queue; if
|
| 817 | * sk == NULL due to previous failures we will just do the
|
| 818 | * multicast send and move the record to the retry queue
|
| 819 | rc = kauditd_send_queue(sk, portid, &audit_queue, 1,
|
| 820 | kauditd_send_multicast_skb,
|
| 821 | kauditd_retry_skb);
|
| 822 | if (sk == NULL || rc < 0)
|
| 823 | auditd_reset();
|
| 824 | sk = NULL;
|
| 825 |
|
| 826 |
|
| 827 | if (net) {
|
| 828 | put_net(net);
|
| 829 | net = NULL;
|
| 830 | }
|
| 831 |
|
| 832 |
|
| 833 | wake_up(&audit_backlog_wait);
|
| 834 |
|
| 835 | |
| 836 | * regardless of if an auditd is connected, as we need to
|
| 837 | * do the multicast send and rotate records from the
|
| 838 | * main queue to the retry/hold queues
|
| 839 | wait_event_freezable(kauditd_wait,
|
| 840 | (skb_queue_len(&audit_queue) ? 1 : 0));
|
| 841 | }
|
| 842 |
|
| 843 | return 0;
|
| 844 | }
|
| 845 |
|
| 846 | int audit_send_list(void *_dest)
|
| 847 | {
|
| 848 | struct audit_netlink_list *dest = _dest;
|
| 849 | struct sk_buff *skb;
|
| 850 | struct sock *sk = audit_get_sk(dest->net);
|
| 851 |
|
| 852 |
|
| 853 | mutex_lock(&audit_cmd_mutex);
|
| 854 | mutex_unlock(&audit_cmd_mutex);
|
| 855 |
|
| 856 | while ((skb = __skb_dequeue(&dest->q)) != NULL)
|
| 857 | netlink_unicast(sk, skb, dest->portid, 0);
|
| 858 |
|
| 859 | put_net(dest->net);
|
| 860 | kfree(dest);
|
| 861 |
|
| 862 | return 0;
|
| 863 | }
|
| 864 |
|
| 865 | struct sk_buff *audit_make_reply(int seq, int type, int done,
|
| 866 | int multi, const void *payload, int size)
|
| 867 | {
|
| 868 | struct sk_buff *skb;
|
| 869 | struct nlmsghdr *nlh;
|
| 870 | void *data;
|
| 871 | int flags = multi ? NLM_F_MULTI : 0;
|
| 872 | int t = done ? NLMSG_DONE : type;
|
| 873 |
|
| 874 | skb = nlmsg_new(size, GFP_KERNEL);
|
| 875 | if (!skb)
|
| 876 | return NULL;
|
| 877 |
|
| 878 | nlh = nlmsg_put(skb, 0, seq, t, size, flags);
|
| 879 | if (!nlh)
|
| 880 | goto out_kfree_skb;
|
| 881 | data = nlmsg_data(nlh);
|
| 882 | memcpy(data, payload, size);
|
| 883 | return skb;
|
| 884 |
|
| 885 | out_kfree_skb:
|
| 886 | kfree_skb(skb);
|
| 887 | return NULL;
|
| 888 | }
|
| 889 |
|
| 890 | static int audit_send_reply_thread(void *arg)
|
| 891 | {
|
| 892 | struct audit_reply *reply = (struct audit_reply *)arg;
|
| 893 | struct sock *sk = audit_get_sk(reply->net);
|
| 894 |
|
| 895 | mutex_lock(&audit_cmd_mutex);
|
| 896 | mutex_unlock(&audit_cmd_mutex);
|
| 897 |
|
| 898 | |
| 899 | because our timeout is set to infinite.
|
| 900 | netlink_unicast(sk, reply->skb, reply->portid, 0);
|
| 901 | put_net(reply->net);
|
| 902 | kfree(reply);
|
| 903 | return 0;
|
| 904 | }
|
| 905 |
|
| 906 | |
| 907 | * audit_send_reply - send an audit reply message via netlink
|
| 908 | * @request_skb: skb of request we are replying to (used to target the reply)
|
| 909 | * @seq: sequence number
|
| 910 | * @type: audit message type
|
| 911 | * @done: done (last) flag
|
| 912 | * @multi: multi-part message flag
|
| 913 | * @payload: payload data
|
| 914 | * @size: payload size
|
| 915 | *
|
| 916 | * Allocates an skb, builds the netlink message, and sends it to the port id.
|
| 917 | * No failure notifications.
|
| 918 |
|
| 919 | static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
|
| 920 | int multi, const void *payload, int size)
|
| 921 | {
|
| 922 | struct net *net = sock_net(NETLINK_CB(request_skb).sk);
|
| 923 | struct sk_buff *skb;
|
| 924 | struct task_struct *tsk;
|
| 925 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
|
| 926 | GFP_KERNEL);
|
| 927 |
|
| 928 | if (!reply)
|
| 929 | return;
|
| 930 |
|
| 931 | skb = audit_make_reply(seq, type, done, multi, payload, size);
|
| 932 | if (!skb)
|
| 933 | goto out;
|
| 934 |
|
| 935 | reply->net = get_net(net);
|
| 936 | reply->portid = NETLINK_CB(request_skb).portid;
|
| 937 | reply->skb = skb;
|
| 938 |
|
| 939 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
|
| 940 | if (!IS_ERR(tsk))
|
| 941 | return;
|
| 942 | kfree_skb(skb);
|
| 943 | out:
|
| 944 | kfree(reply);
|
| 945 | }
|
| 946 |
|
| 947 | |
| 948 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
|
| 949 | * control messages.
|
| 950 |
|
| 951 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
|
| 952 | {
|
| 953 | int err = 0;
|
| 954 |
|
| 955 |
|
| 956 | |
| 957 | * We return ECONNREFUSED because it tricks userspace into thinking
|
| 958 | * that audit was not configured into the kernel. Lots of users
|
| 959 | * configure their PAM stack (because that's what the distro does)
|
| 960 | * to reject login if unable to send messages to audit. If we return
|
| 961 | * ECONNREFUSED the PAM stack thinks the kernel does not have audit
|
| 962 | * configured in and will let login proceed. If we return EPERM
|
| 963 | * userspace will reject all logins. This should be removed when we
|
| 964 | * support non init namespaces!!
|
| 965 |
|
| 966 | if (current_user_ns() != &init_user_ns)
|
| 967 | return -ECONNREFUSED;
|
| 968 |
|
| 969 | switch (msg_type) {
|
| 970 | case AUDIT_LIST:
|
| 971 | case AUDIT_ADD:
|
| 972 | case AUDIT_DEL:
|
| 973 | return -EOPNOTSUPP;
|
| 974 | case AUDIT_GET:
|
| 975 | case AUDIT_SET:
|
| 976 | case AUDIT_GET_FEATURE:
|
| 977 | case AUDIT_SET_FEATURE:
|
| 978 | case AUDIT_LIST_RULES:
|
| 979 | case AUDIT_ADD_RULE:
|
| 980 | case AUDIT_DEL_RULE:
|
| 981 | case AUDIT_SIGNAL_INFO:
|
| 982 | case AUDIT_TTY_GET:
|
| 983 | case AUDIT_TTY_SET:
|
| 984 | case AUDIT_TRIM:
|
| 985 | case AUDIT_MAKE_EQUIV:
|
| 986 | |
| 987 | * for now.
|
| 988 | if (task_active_pid_ns(current) != &init_pid_ns)
|
| 989 | return -EPERM;
|
| 990 |
|
| 991 | if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
|
| 992 | err = -EPERM;
|
| 993 | break;
|
| 994 | case AUDIT_USER:
|
| 995 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
|
| 996 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
|
| 997 | if (!netlink_capable(skb, CAP_AUDIT_WRITE))
|
| 998 | err = -EPERM;
|
| 999 | break;
|
| 1000 | default:
|
| 1001 | err = -EINVAL;
|
| 1002 | }
|
| 1003 |
|
| 1004 | return err;
|
| 1005 | }
|
| 1006 |
|
| 1007 | static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
|
| 1008 | {
|
| 1009 | uid_t uid = from_kuid(&init_user_ns, current_uid());
|
| 1010 | pid_t pid = task_tgid_nr(current);
|
| 1011 |
|
| 1012 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
|
| 1013 | *ab = NULL;
|
| 1014 | return;
|
| 1015 | }
|
| 1016 |
|
| 1017 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
|
| 1018 | if (unlikely(!*ab))
|
| 1019 | return;
|
| 1020 | audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
|
| 1021 | audit_log_session_info(*ab);
|
| 1022 | audit_log_task_context(*ab);
|
| 1023 | }
|
| 1024 |
|
| 1025 | int is_audit_feature_set(int i)
|
| 1026 | {
|
| 1027 | return af.features & AUDIT_FEATURE_TO_MASK(i);
|
| 1028 | }
|
| 1029 |
|
| 1030 |
|
| 1031 | static int audit_get_feature(struct sk_buff *skb)
|
| 1032 | {
|
| 1033 | u32 seq;
|
| 1034 |
|
| 1035 | seq = nlmsg_hdr(skb)->nlmsg_seq;
|
| 1036 |
|
| 1037 | audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
|
| 1038 |
|
| 1039 | return 0;
|
| 1040 | }
|
| 1041 |
|
| 1042 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
|
| 1043 | u32 old_lock, u32 new_lock, int res)
|
| 1044 | {
|
| 1045 | struct audit_buffer *ab;
|
| 1046 |
|
| 1047 | if (audit_enabled == AUDIT_OFF)
|
| 1048 | return;
|
| 1049 |
|
| 1050 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE);
|
| 1051 | audit_log_task_info(ab, current);
|
| 1052 | audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
|
| 1053 | audit_feature_names[which], !!old_feature, !!new_feature,
|
| 1054 | !!old_lock, !!new_lock, res);
|
| 1055 | audit_log_end(ab);
|
| 1056 | }
|
| 1057 |
|
| 1058 | static int audit_set_feature(struct sk_buff *skb)
|
| 1059 | {
|
| 1060 | struct audit_features *uaf;
|
| 1061 | int i;
|
| 1062 |
|
| 1063 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
|
| 1064 | uaf = nlmsg_data(nlmsg_hdr(skb));
|
| 1065 |
|
| 1066 |
|
| 1067 |
|
| 1068 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
|
| 1069 | u32 feature = AUDIT_FEATURE_TO_MASK(i);
|
| 1070 | u32 old_feature, new_feature, old_lock, new_lock;
|
| 1071 |
|
| 1072 |
|
| 1073 | if (!(feature & uaf->mask))
|
| 1074 | continue;
|
| 1075 |
|
| 1076 | old_feature = af.features & feature;
|
| 1077 | new_feature = uaf->features & feature;
|
| 1078 | new_lock = (uaf->lock | af.lock) & feature;
|
| 1079 | old_lock = af.lock & feature;
|
| 1080 |
|
| 1081 |
|
| 1082 | if (old_lock && (new_feature != old_feature)) {
|
| 1083 | audit_log_feature_change(i, old_feature, new_feature,
|
| 1084 | old_lock, new_lock, 0);
|
| 1085 | return -EPERM;
|
| 1086 | }
|
| 1087 | }
|
| 1088 |
|
| 1089 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
|
| 1090 | u32 feature = AUDIT_FEATURE_TO_MASK(i);
|
| 1091 | u32 old_feature, new_feature, old_lock, new_lock;
|
| 1092 |
|
| 1093 |
|
| 1094 | if (!(feature & uaf->mask))
|
| 1095 | continue;
|
| 1096 |
|
| 1097 | old_feature = af.features & feature;
|
| 1098 | new_feature = uaf->features & feature;
|
| 1099 | old_lock = af.lock & feature;
|
| 1100 | new_lock = (uaf->lock | af.lock) & feature;
|
| 1101 |
|
| 1102 | if (new_feature != old_feature)
|
| 1103 | audit_log_feature_change(i, old_feature, new_feature,
|
| 1104 | old_lock, new_lock, 1);
|
| 1105 |
|
| 1106 | if (new_feature)
|
| 1107 | af.features |= feature;
|
| 1108 | else
|
| 1109 | af.features &= ~feature;
|
| 1110 | af.lock |= new_lock;
|
| 1111 | }
|
| 1112 |
|
| 1113 | return 0;
|
| 1114 | }
|
| 1115 |
|
| 1116 | static int audit_replace(struct pid *pid)
|
| 1117 | {
|
| 1118 | pid_t pvnr;
|
| 1119 | struct sk_buff *skb;
|
| 1120 |
|
| 1121 | pvnr = pid_vnr(pid);
|
| 1122 | skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr));
|
| 1123 | if (!skb)
|
| 1124 | return -ENOMEM;
|
| 1125 | return auditd_send_unicast_skb(skb);
|
| 1126 | }
|
| 1127 |
|
| 1128 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
|
| 1129 | {
|
| 1130 | u32 seq;
|
| 1131 | void *data;
|
| 1132 | int err;
|
| 1133 | struct audit_buffer *ab;
|
| 1134 | u16 msg_type = nlh->nlmsg_type;
|
| 1135 | struct audit_sig_info *sig_data;
|
| 1136 | char *ctx = NULL;
|
| 1137 | u32 len;
|
| 1138 |
|
| 1139 | err = audit_netlink_ok(skb, msg_type);
|
| 1140 | if (err)
|
| 1141 | return err;
|
| 1142 |
|
| 1143 | seq = nlh->nlmsg_seq;
|
| 1144 | data = nlmsg_data(nlh);
|
| 1145 |
|
| 1146 | switch (msg_type) {
|
| 1147 | case AUDIT_GET: {
|
| 1148 | struct audit_status s;
|
| 1149 | memset(&s, 0, sizeof(s));
|
| 1150 | s.enabled = audit_enabled;
|
| 1151 | s.failure = audit_failure;
|
| 1152 | |
| 1153 | * namespace
|
| 1154 | s.pid = auditd_pid_vnr();
|
| 1155 | s.rate_limit = audit_rate_limit;
|
| 1156 | s.backlog_limit = audit_backlog_limit;
|
| 1157 | s.lost = atomic_read(&audit_lost);
|
| 1158 | s.backlog = skb_queue_len(&audit_queue);
|
| 1159 | s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
|
| 1160 | s.backlog_wait_time = audit_backlog_wait_time;
|
| 1161 | audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
|
| 1162 | break;
|
| 1163 | }
|
| 1164 | case AUDIT_SET: {
|
| 1165 | struct audit_status s;
|
| 1166 | memset(&s, 0, sizeof(s));
|
| 1167 |
|
| 1168 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
|
| 1169 | if (s.mask & AUDIT_STATUS_ENABLED) {
|
| 1170 | err = audit_set_enabled(s.enabled);
|
| 1171 | if (err < 0)
|
| 1172 | return err;
|
| 1173 | }
|
| 1174 | if (s.mask & AUDIT_STATUS_FAILURE) {
|
| 1175 | err = audit_set_failure(s.failure);
|
| 1176 | if (err < 0)
|
| 1177 | return err;
|
| 1178 | }
|
| 1179 | if (s.mask & AUDIT_STATUS_PID) {
|
| 1180 | |
| 1181 | * because the s.pid value is relative to the
|
| 1182 | * namespace of the caller; at present this
|
| 1183 | * doesn't matter much since you can really only
|
| 1184 | * run auditd from the initial pid namespace, but
|
| 1185 | * something to keep in mind if this changes
|
| 1186 | pid_t new_pid = s.pid;
|
| 1187 | pid_t auditd_pid;
|
| 1188 | struct pid *req_pid = task_tgid(current);
|
| 1189 |
|
| 1190 |
|
| 1191 | if (new_pid != pid_vnr(req_pid))
|
| 1192 | return -EINVAL;
|
| 1193 |
|
| 1194 |
|
| 1195 | audit_replace(req_pid);
|
| 1196 |
|
| 1197 | auditd_pid = auditd_pid_vnr();
|
| 1198 |
|
| 1199 | if ((!new_pid) && (new_pid != auditd_pid)) {
|
| 1200 | audit_log_config_change("audit_pid", new_pid,
|
| 1201 | auditd_pid, 0);
|
| 1202 | return -EACCES;
|
| 1203 | }
|
| 1204 |
|
| 1205 | if (auditd_pid && new_pid) {
|
| 1206 | audit_log_config_change("audit_pid", new_pid,
|
| 1207 | auditd_pid, 0);
|
| 1208 | return -EEXIST;
|
| 1209 | }
|
| 1210 |
|
| 1211 | if (new_pid) {
|
| 1212 |
|
| 1213 | err = auditd_set(req_pid,
|
| 1214 | NETLINK_CB(skb).portid,
|
| 1215 | sock_net(NETLINK_CB(skb).sk));
|
| 1216 | if (audit_enabled != AUDIT_OFF)
|
| 1217 | audit_log_config_change("audit_pid",
|
| 1218 | new_pid,
|
| 1219 | auditd_pid,
|
| 1220 | err ? 0 : 1);
|
| 1221 | if (err)
|
| 1222 | return err;
|
| 1223 |
|
| 1224 |
|
| 1225 | wake_up_interruptible(&kauditd_wait);
|
| 1226 | } else {
|
| 1227 | if (audit_enabled != AUDIT_OFF)
|
| 1228 | audit_log_config_change("audit_pid",
|
| 1229 | new_pid,
|
| 1230 | auditd_pid, 1);
|
| 1231 |
|
| 1232 |
|
| 1233 | auditd_reset();
|
| 1234 | }
|
| 1235 | }
|
| 1236 | if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
|
| 1237 | err = audit_set_rate_limit(s.rate_limit);
|
| 1238 | if (err < 0)
|
| 1239 | return err;
|
| 1240 | }
|
| 1241 | if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
|
| 1242 | err = audit_set_backlog_limit(s.backlog_limit);
|
| 1243 | if (err < 0)
|
| 1244 | return err;
|
| 1245 | }
|
| 1246 | if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
|
| 1247 | if (sizeof(s) > (size_t)nlh->nlmsg_len)
|
| 1248 | return -EINVAL;
|
| 1249 | if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
|
| 1250 | return -EINVAL;
|
| 1251 | err = audit_set_backlog_wait_time(s.backlog_wait_time);
|
| 1252 | if (err < 0)
|
| 1253 | return err;
|
| 1254 | }
|
| 1255 | if (s.mask == AUDIT_STATUS_LOST) {
|
| 1256 | u32 lost = atomic_xchg(&audit_lost, 0);
|
| 1257 |
|
| 1258 | audit_log_config_change("lost", 0, lost, 1);
|
| 1259 | return lost;
|
| 1260 | }
|
| 1261 | break;
|
| 1262 | }
|
| 1263 | case AUDIT_GET_FEATURE:
|
| 1264 | err = audit_get_feature(skb);
|
| 1265 | if (err)
|
| 1266 | return err;
|
| 1267 | break;
|
| 1268 | case AUDIT_SET_FEATURE:
|
| 1269 | err = audit_set_feature(skb);
|
| 1270 | if (err)
|
| 1271 | return err;
|
| 1272 | break;
|
| 1273 | case AUDIT_USER:
|
| 1274 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
|
| 1275 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
|
| 1276 | if (!audit_enabled && msg_type != AUDIT_USER_AVC)
|
| 1277 | return 0;
|
| 1278 |
|
| 1279 | err = audit_filter(msg_type, AUDIT_FILTER_USER);
|
| 1280 | if (err == 1) {
|
| 1281 | err = 0;
|
| 1282 | if (msg_type == AUDIT_USER_TTY) {
|
| 1283 | err = tty_audit_push();
|
| 1284 | if (err)
|
| 1285 | break;
|
| 1286 | }
|
| 1287 | audit_log_common_recv_msg(&ab, msg_type);
|
| 1288 | if (msg_type != AUDIT_USER_TTY)
|
| 1289 | audit_log_format(ab, " msg='%.*s'",
|
| 1290 | AUDIT_MESSAGE_TEXT_MAX,
|
| 1291 | (char *)data);
|
| 1292 | else {
|
| 1293 | int size;
|
| 1294 |
|
| 1295 | audit_log_format(ab, " data=");
|
| 1296 | size = nlmsg_len(nlh);
|
| 1297 | if (size > 0 &&
|
| 1298 | ((unsigned char *)data)[size - 1] == '\0')
|
| 1299 | size--;
|
| 1300 | audit_log_n_untrustedstring(ab, data, size);
|
| 1301 | }
|
| 1302 | audit_log_end(ab);
|
| 1303 | }
|
| 1304 | break;
|
| 1305 | case AUDIT_ADD_RULE:
|
| 1306 | case AUDIT_DEL_RULE:
|
| 1307 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
|
| 1308 | return -EINVAL;
|
| 1309 | if (audit_enabled == AUDIT_LOCKED) {
|
| 1310 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
|
| 1311 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
|
| 1312 | audit_log_end(ab);
|
| 1313 | return -EPERM;
|
| 1314 | }
|
| 1315 | err = audit_rule_change(msg_type, seq, data, nlmsg_len(nlh));
|
| 1316 | break;
|
| 1317 | case AUDIT_LIST_RULES:
|
| 1318 | err = audit_list_rules_send(skb, seq);
|
| 1319 | break;
|
| 1320 | case AUDIT_TRIM:
|
| 1321 | audit_trim_trees();
|
| 1322 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
|
| 1323 | audit_log_format(ab, " op=trim res=1");
|
| 1324 | audit_log_end(ab);
|
| 1325 | break;
|
| 1326 | case AUDIT_MAKE_EQUIV: {
|
| 1327 | void *bufp = data;
|
| 1328 | u32 sizes[2];
|
| 1329 | size_t msglen = nlmsg_len(nlh);
|
| 1330 | char *old, *new;
|
| 1331 |
|
| 1332 | err = -EINVAL;
|
| 1333 | if (msglen < 2 * sizeof(u32))
|
| 1334 | break;
|
| 1335 | memcpy(sizes, bufp, 2 * sizeof(u32));
|
| 1336 | bufp += 2 * sizeof(u32);
|
| 1337 | msglen -= 2 * sizeof(u32);
|
| 1338 | old = audit_unpack_string(&bufp, &msglen, sizes[0]);
|
| 1339 | if (IS_ERR(old)) {
|
| 1340 | err = PTR_ERR(old);
|
| 1341 | break;
|
| 1342 | }
|
| 1343 | new = audit_unpack_string(&bufp, &msglen, sizes[1]);
|
| 1344 | if (IS_ERR(new)) {
|
| 1345 | err = PTR_ERR(new);
|
| 1346 | kfree(old);
|
| 1347 | break;
|
| 1348 | }
|
| 1349 |
|
| 1350 | err = audit_tag_tree(old, new);
|
| 1351 |
|
| 1352 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
|
| 1353 |
|
| 1354 | audit_log_format(ab, " op=make_equiv old=");
|
| 1355 | audit_log_untrustedstring(ab, old);
|
| 1356 | audit_log_format(ab, " new=");
|
| 1357 | audit_log_untrustedstring(ab, new);
|
| 1358 | audit_log_format(ab, " res=%d", !err);
|
| 1359 | audit_log_end(ab);
|
| 1360 | kfree(old);
|
| 1361 | kfree(new);
|
| 1362 | break;
|
| 1363 | }
|
| 1364 | case AUDIT_SIGNAL_INFO:
|
| 1365 | len = 0;
|
| 1366 | if (audit_sig_sid) {
|
| 1367 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
|
| 1368 | if (err)
|
| 1369 | return err;
|
| 1370 | }
|
| 1371 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
|
| 1372 | if (!sig_data) {
|
| 1373 | if (audit_sig_sid)
|
| 1374 | security_release_secctx(ctx, len);
|
| 1375 | return -ENOMEM;
|
| 1376 | }
|
| 1377 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
|
| 1378 | sig_data->pid = audit_sig_pid;
|
| 1379 | if (audit_sig_sid) {
|
| 1380 | memcpy(sig_data->ctx, ctx, len);
|
| 1381 | security_release_secctx(ctx, len);
|
| 1382 | }
|
| 1383 | audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
|
| 1384 | sig_data, sizeof(*sig_data) + len);
|
| 1385 | kfree(sig_data);
|
| 1386 | break;
|
| 1387 | case AUDIT_TTY_GET: {
|
| 1388 | struct audit_tty_status s;
|
| 1389 | unsigned int t;
|
| 1390 |
|
| 1391 | t = READ_ONCE(current->signal->audit_tty);
|
| 1392 | s.enabled = t & AUDIT_TTY_ENABLE;
|
| 1393 | s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
|
| 1394 |
|
| 1395 | audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
|
| 1396 | break;
|
| 1397 | }
|
| 1398 | case AUDIT_TTY_SET: {
|
| 1399 | struct audit_tty_status s, old;
|
| 1400 | struct audit_buffer *ab;
|
| 1401 | unsigned int t;
|
| 1402 |
|
| 1403 | memset(&s, 0, sizeof(s));
|
| 1404 |
|
| 1405 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
|
| 1406 |
|
| 1407 | if ((s.enabled != 0 && s.enabled != 1) ||
|
| 1408 | (s.log_passwd != 0 && s.log_passwd != 1))
|
| 1409 | err = -EINVAL;
|
| 1410 |
|
| 1411 | if (err)
|
| 1412 | t = READ_ONCE(current->signal->audit_tty);
|
| 1413 | else {
|
| 1414 | t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
|
| 1415 | t = xchg(¤t->signal->audit_tty, t);
|
| 1416 | }
|
| 1417 | old.enabled = t & AUDIT_TTY_ENABLE;
|
| 1418 | old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
|
| 1419 |
|
| 1420 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
|
| 1421 | audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
|
| 1422 | " old-log_passwd=%d new-log_passwd=%d res=%d",
|
| 1423 | old.enabled, s.enabled, old.log_passwd,
|
| 1424 | s.log_passwd, !err);
|
| 1425 | audit_log_end(ab);
|
| 1426 | break;
|
| 1427 | }
|
| 1428 | default:
|
| 1429 | err = -EINVAL;
|
| 1430 | break;
|
| 1431 | }
|
| 1432 |
|
| 1433 | return err < 0 ? err : 0;
|
| 1434 | }
|
| 1435 |
|
| 1436 | |
| 1437 | * audit_receive - receive messages from a netlink control socket
|
| 1438 | * @skb: the message buffer
|
| 1439 | *
|
| 1440 | * Parse the provided skb and deal with any messages that may be present,
|
| 1441 | * malformed skbs are discarded.
|
| 1442 |
|
| 1443 | static void audit_receive(struct sk_buff *skb)
|
| 1444 | {
|
| 1445 | struct nlmsghdr *nlh;
|
| 1446 | |
| 1447 | * len MUST be signed for nlmsg_next to be able to dec it below 0
|
| 1448 | * if the nlmsg_len was not aligned
|
| 1449 |
|
| 1450 | int len;
|
| 1451 | int err;
|
| 1452 |
|
| 1453 | nlh = nlmsg_hdr(skb);
|
| 1454 | len = skb->len;
|
| 1455 |
|
| 1456 | mutex_lock(&audit_cmd_mutex);
|
| 1457 | while (nlmsg_ok(nlh, len)) {
|
| 1458 | err = audit_receive_msg(skb, nlh);
|
| 1459 |
|
| 1460 | if (err || (nlh->nlmsg_flags & NLM_F_ACK))
|
| 1461 | netlink_ack(skb, nlh, err, NULL);
|
| 1462 |
|
| 1463 | nlh = nlmsg_next(nlh, &len);
|
| 1464 | }
|
| 1465 | mutex_unlock(&audit_cmd_mutex);
|
| 1466 | }
|
| 1467 |
|
| 1468 |
|
| 1469 | static int audit_bind(struct net *net, int group)
|
| 1470 | {
|
| 1471 | if (!capable(CAP_AUDIT_READ))
|
| 1472 | return -EPERM;
|
| 1473 |
|
| 1474 | return 0;
|
| 1475 | }
|
| 1476 |
|
| 1477 | static int __net_init audit_net_init(struct net *net)
|
| 1478 | {
|
| 1479 | struct netlink_kernel_cfg cfg = {
|
| 1480 | .input = audit_receive,
|
| 1481 | .bind = audit_bind,
|
| 1482 | .flags = NL_CFG_F_NONROOT_RECV,
|
| 1483 | .groups = AUDIT_NLGRP_MAX,
|
| 1484 | };
|
| 1485 |
|
| 1486 | struct audit_net *aunet = net_generic(net, audit_net_id);
|
| 1487 |
|
| 1488 | aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
|
| 1489 | if (aunet->sk == NULL) {
|
| 1490 | audit_panic("cannot initialize netlink socket in namespace");
|
| 1491 | return -ENOMEM;
|
| 1492 | }
|
| 1493 | aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
|
| 1494 |
|
| 1495 | return 0;
|
| 1496 | }
|
| 1497 |
|
| 1498 | static void __net_exit audit_net_exit(struct net *net)
|
| 1499 | {
|
| 1500 | struct audit_net *aunet = net_generic(net, audit_net_id);
|
| 1501 |
|
| 1502 | |
| 1503 | * connection and potentially reset it here if it lives in this
|
| 1504 | * namespace, but since the auditd connection tracking struct holds a
|
| 1505 | * reference to this namespace (see auditd_set()) we are only ever
|
| 1506 | * going to get here after that connection has been released
|
| 1507 |
|
| 1508 | netlink_kernel_release(aunet->sk);
|
| 1509 | }
|
| 1510 |
|
| 1511 | static struct pernet_operations audit_net_ops __net_initdata = {
|
| 1512 | .init = audit_net_init,
|
| 1513 | .exit = audit_net_exit,
|
| 1514 | .id = &audit_net_id,
|
| 1515 | .size = sizeof(struct audit_net),
|
| 1516 | };
|
| 1517 |
|
| 1518 |
|
| 1519 | static int __init audit_init(void)
|
| 1520 | {
|
| 1521 | int i;
|
| 1522 |
|
| 1523 | if (audit_initialized == AUDIT_DISABLED)
|
| 1524 | return 0;
|
| 1525 |
|
| 1526 | audit_buffer_cache = kmem_cache_create("audit_buffer",
|
| 1527 | sizeof(struct audit_buffer),
|
| 1528 | 0, SLAB_PANIC, NULL);
|
| 1529 |
|
| 1530 | skb_queue_head_init(&audit_queue);
|
| 1531 | skb_queue_head_init(&audit_retry_queue);
|
| 1532 | skb_queue_head_init(&audit_hold_queue);
|
| 1533 |
|
| 1534 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
|
| 1535 | INIT_LIST_HEAD(&audit_inode_hash[i]);
|
| 1536 |
|
| 1537 | pr_info("initializing netlink subsys (%s)\n",
|
| 1538 | audit_default ? "enabled" : "disabled");
|
| 1539 | register_pernet_subsys(&audit_net_ops);
|
| 1540 |
|
| 1541 | audit_initialized = AUDIT_INITIALIZED;
|
| 1542 | audit_enabled = audit_default;
|
| 1543 | audit_ever_enabled |= !!audit_default;
|
| 1544 |
|
| 1545 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
|
| 1546 | if (IS_ERR(kauditd_task)) {
|
| 1547 | int err = PTR_ERR(kauditd_task);
|
| 1548 | panic("audit: failed to start the kauditd thread (%d)\n", err);
|
| 1549 | }
|
| 1550 |
|
| 1551 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL,
|
| 1552 | "state=initialized audit_enabled=%u res=1",
|
| 1553 | audit_enabled);
|
| 1554 |
|
| 1555 | return 0;
|
| 1556 | }
|
| 1557 | __initcall(audit_init);
|
| 1558 |
|
| 1559 |
|
| 1560 | static int __init audit_enable(char *str)
|
| 1561 | {
|
| 1562 | audit_default = !!simple_strtol(str, NULL, 0);
|
| 1563 | if (!audit_default)
|
| 1564 | audit_initialized = AUDIT_DISABLED;
|
| 1565 |
|
| 1566 | pr_info("%s\n", audit_default ?
|
| 1567 | "enabled (after initialization)" : "disabled (until reboot)");
|
| 1568 |
|
| 1569 | return 1;
|
| 1570 | }
|
| 1571 | __setup("audit=", audit_enable);
|
| 1572 |
|
| 1573 | |
| 1574 | * audit_backlog_limit=<n>
|
| 1575 | static int __init audit_backlog_limit_set(char *str)
|
| 1576 | {
|
| 1577 | u32 audit_backlog_limit_arg;
|
| 1578 |
|
| 1579 | pr_info("audit_backlog_limit: ");
|
| 1580 | if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
|
| 1581 | pr_cont("using default of %u, unable to parse %s\n",
|
| 1582 | audit_backlog_limit, str);
|
| 1583 | return 1;
|
| 1584 | }
|
| 1585 |
|
| 1586 | audit_backlog_limit = audit_backlog_limit_arg;
|
| 1587 | pr_cont("%d\n", audit_backlog_limit);
|
| 1588 |
|
| 1589 | return 1;
|
| 1590 | }
|
| 1591 | __setup("audit_backlog_limit=", audit_backlog_limit_set);
|
| 1592 |
|
| 1593 | static void audit_buffer_free(struct audit_buffer *ab)
|
| 1594 | {
|
| 1595 | if (!ab)
|
| 1596 | return;
|
| 1597 |
|
| 1598 | kfree_skb(ab->skb);
|
| 1599 | kmem_cache_free(audit_buffer_cache, ab);
|
| 1600 | }
|
| 1601 |
|
| 1602 | static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
|
| 1603 | gfp_t gfp_mask, int type)
|
| 1604 | {
|
| 1605 | struct audit_buffer *ab;
|
| 1606 |
|
| 1607 | ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask);
|
| 1608 | if (!ab)
|
| 1609 | return NULL;
|
| 1610 |
|
| 1611 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
|
| 1612 | if (!ab->skb)
|
| 1613 | goto err;
|
| 1614 | if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
|
| 1615 | goto err;
|
| 1616 |
|
| 1617 | ab->ctx = ctx;
|
| 1618 | ab->gfp_mask = gfp_mask;
|
| 1619 |
|
| 1620 | return ab;
|
| 1621 |
|
| 1622 | err:
|
| 1623 | audit_buffer_free(ab);
|
| 1624 | return NULL;
|
| 1625 | }
|
| 1626 |
|
| 1627 | |
| 1628 | * audit_serial - compute a serial number for the audit record
|
| 1629 | *
|
| 1630 | * Compute a serial number for the audit record. Audit records are
|
| 1631 | * written to user-space as soon as they are generated, so a complete
|
| 1632 | * audit record may be written in several pieces. The timestamp of the
|
| 1633 | * record and this serial number are used by the user-space tools to
|
| 1634 | * determine which pieces belong to the same audit record. The
|
| 1635 | * (timestamp,serial) tuple is unique for each syscall and is live from
|
| 1636 | * syscall entry to syscall exit.
|
| 1637 | *
|
| 1638 | * NOTE: Another possibility is to store the formatted records off the
|
| 1639 | * audit context (for those records that have a context), and emit them
|
| 1640 | * all at syscall exit. However, this could delay the reporting of
|
| 1641 | * significant errors until syscall exit (or never, if the system
|
| 1642 | * halts).
|
| 1643 |
|
| 1644 | unsigned int audit_serial(void)
|
| 1645 | {
|
| 1646 | static atomic_t serial = ATOMIC_INIT(0);
|
| 1647 |
|
| 1648 | return atomic_add_return(1, &serial);
|
| 1649 | }
|
| 1650 |
|
| 1651 | static inline void audit_get_stamp(struct audit_context *ctx,
|
| 1652 | struct timespec64 *t, unsigned int *serial)
|
| 1653 | {
|
| 1654 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
|
| 1655 | ktime_get_real_ts64(t);
|
| 1656 | *serial = audit_serial();
|
| 1657 | }
|
| 1658 | }
|
| 1659 |
|
| 1660 | |
| 1661 | * audit_log_start - obtain an audit buffer
|
| 1662 | * @ctx: audit_context (may be NULL)
|
| 1663 | * @gfp_mask: type of allocation
|
| 1664 | * @type: audit message type
|
| 1665 | *
|
| 1666 | * Returns audit_buffer pointer on success or NULL on error.
|
| 1667 | *
|
| 1668 | * Obtain an audit buffer. This routine does locking to obtain the
|
| 1669 | * audit buffer, but then no locking is required for calls to
|
| 1670 | * audit_log_*format. If the task (ctx) is a task that is currently in a
|
| 1671 | * syscall, then the syscall is marked as auditable and an audit record
|
| 1672 | * will be written at syscall exit. If there is no associated task, then
|
| 1673 | * task context (ctx) should be NULL.
|
| 1674 |
|
| 1675 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
|
| 1676 | int type)
|
| 1677 | {
|
| 1678 | struct audit_buffer *ab;
|
| 1679 | struct timespec64 t;
|
| 1680 | unsigned int uninitialized_var(serial);
|
| 1681 |
|
| 1682 | if (audit_initialized != AUDIT_INITIALIZED)
|
| 1683 | return NULL;
|
| 1684 |
|
| 1685 | if (unlikely(!audit_filter(type, AUDIT_FILTER_TYPE)))
|
| 1686 | return NULL;
|
| 1687 |
|
| 1688 | |
| 1689 | * 1. auditd generated record - since we need auditd to drain the
|
| 1690 | * queue; also, when we are checking for auditd, compare PIDs using
|
| 1691 | * task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
|
| 1692 | * using a PID anchored in the caller's namespace
|
| 1693 | * 2. generator holding the audit_cmd_mutex - we don't want to block
|
| 1694 | * while holding the mutex
|
| 1695 | if (!(auditd_test_task(current) ||
|
| 1696 | (current == __mutex_owner(&audit_cmd_mutex)))) {
|
| 1697 | long stime = audit_backlog_wait_time;
|
| 1698 |
|
| 1699 | while (audit_backlog_limit &&
|
| 1700 | (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
|
| 1701 |
|
| 1702 | wake_up_interruptible(&kauditd_wait);
|
| 1703 |
|
| 1704 | |
| 1705 | * backlog wait limit
|
| 1706 | if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
|
| 1707 | DECLARE_WAITQUEUE(wait, current);
|
| 1708 |
|
| 1709 | add_wait_queue_exclusive(&audit_backlog_wait,
|
| 1710 | &wait);
|
| 1711 | set_current_state(TASK_UNINTERRUPTIBLE);
|
| 1712 | stime = schedule_timeout(stime);
|
| 1713 | remove_wait_queue(&audit_backlog_wait, &wait);
|
| 1714 | } else {
|
| 1715 | if (audit_rate_check() && printk_ratelimit())
|
| 1716 | pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
|
| 1717 | skb_queue_len(&audit_queue),
|
| 1718 | audit_backlog_limit);
|
| 1719 | audit_log_lost("backlog limit exceeded");
|
| 1720 | return NULL;
|
| 1721 | }
|
| 1722 | }
|
| 1723 | }
|
| 1724 |
|
| 1725 | ab = audit_buffer_alloc(ctx, gfp_mask, type);
|
| 1726 | if (!ab) {
|
| 1727 | audit_log_lost("out of memory in audit_log_start");
|
| 1728 | return NULL;
|
| 1729 | }
|
| 1730 |
|
| 1731 | audit_get_stamp(ab->ctx, &t, &serial);
|
| 1732 | audit_log_format(ab, "audit(%llu.%03lu:%u): ",
|
| 1733 | (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
|
| 1734 |
|
| 1735 | return ab;
|
| 1736 | }
|
| 1737 |
|
| 1738 | |
| 1739 | * audit_expand - expand skb in the audit buffer
|
| 1740 | * @ab: audit_buffer
|
| 1741 | * @extra: space to add at tail of the skb
|
| 1742 | *
|
| 1743 | * Returns 0 (no space) on failed expansion, or available space if
|
| 1744 | * successful.
|
| 1745 |
|
| 1746 | static inline int audit_expand(struct audit_buffer *ab, int extra)
|
| 1747 | {
|
| 1748 | struct sk_buff *skb = ab->skb;
|
| 1749 | int oldtail = skb_tailroom(skb);
|
| 1750 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
|
| 1751 | int newtail = skb_tailroom(skb);
|
| 1752 |
|
| 1753 | if (ret < 0) {
|
| 1754 | audit_log_lost("out of memory in audit_expand");
|
| 1755 | return 0;
|
| 1756 | }
|
| 1757 |
|
| 1758 | skb->truesize += newtail - oldtail;
|
| 1759 | return newtail;
|
| 1760 | }
|
| 1761 |
|
| 1762 | |
| 1763 | * Format an audit message into the audit buffer. If there isn't enough
|
| 1764 | * room in the audit buffer, more room will be allocated and vsnprint
|
| 1765 | * will be called a second time. Currently, we assume that a printk
|
| 1766 | * can't format message larger than 1024 bytes, so we don't either.
|
| 1767 |
|
| 1768 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
|
| 1769 | va_list args)
|
| 1770 | {
|
| 1771 | int len, avail;
|
| 1772 | struct sk_buff *skb;
|
| 1773 | va_list args2;
|
| 1774 |
|
| 1775 | if (!ab)
|
| 1776 | return;
|
| 1777 |
|
| 1778 | BUG_ON(!ab->skb);
|
| 1779 | skb = ab->skb;
|
| 1780 | avail = skb_tailroom(skb);
|
| 1781 | if (avail == 0) {
|
| 1782 | avail = audit_expand(ab, AUDIT_BUFSIZ);
|
| 1783 | if (!avail)
|
| 1784 | goto out;
|
| 1785 | }
|
| 1786 | va_copy(args2, args);
|
| 1787 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
|
| 1788 | if (len >= avail) {
|
| 1789 | |
| 1790 | * here and AUDIT_BUFSIZ is at least 1024, then we can
|
| 1791 | * log everything that printk could have logged.
|
| 1792 | avail = audit_expand(ab,
|
| 1793 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
|
| 1794 | if (!avail)
|
| 1795 | goto out_va_end;
|
| 1796 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
|
| 1797 | }
|
| 1798 | if (len > 0)
|
| 1799 | skb_put(skb, len);
|
| 1800 | out_va_end:
|
| 1801 | va_end(args2);
|
| 1802 | out:
|
| 1803 | return;
|
| 1804 | }
|
| 1805 |
|
| 1806 | |
| 1807 | * audit_log_format - format a message into the audit buffer.
|
| 1808 | * @ab: audit_buffer
|
| 1809 | * @fmt: format string
|
| 1810 | * @...: optional parameters matching @fmt string
|
| 1811 | *
|
| 1812 | * All the work is done in audit_log_vformat.
|
| 1813 |
|
| 1814 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
|
| 1815 | {
|
| 1816 | va_list args;
|
| 1817 |
|
| 1818 | if (!ab)
|
| 1819 | return;
|
| 1820 | va_start(args, fmt);
|
| 1821 | audit_log_vformat(ab, fmt, args);
|
| 1822 | va_end(args);
|
| 1823 | }
|
| 1824 |
|
| 1825 | |
| 1826 | * audit_log_hex - convert a buffer to hex and append it to the audit skb
|
| 1827 | * @ab: the audit_buffer
|
| 1828 | * @buf: buffer to convert to hex
|
| 1829 | * @len: length of @buf to be converted
|
| 1830 | *
|
| 1831 | * No return value; failure to expand is silently ignored.
|
| 1832 | *
|
| 1833 | * This function will take the passed buf and convert it into a string of
|
| 1834 | * ascii hex digits. The new string is placed onto the skb.
|
| 1835 |
|
| 1836 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
|
| 1837 | size_t len)
|
| 1838 | {
|
| 1839 | int i, avail, new_len;
|
| 1840 | unsigned char *ptr;
|
| 1841 | struct sk_buff *skb;
|
| 1842 |
|
| 1843 | if (!ab)
|
| 1844 | return;
|
| 1845 |
|
| 1846 | BUG_ON(!ab->skb);
|
| 1847 | skb = ab->skb;
|
| 1848 | avail = skb_tailroom(skb);
|
| 1849 | new_len = len<<1;
|
| 1850 | if (new_len >= avail) {
|
| 1851 |
|
| 1852 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
|
| 1853 | avail = audit_expand(ab, new_len);
|
| 1854 | if (!avail)
|
| 1855 | return;
|
| 1856 | }
|
| 1857 |
|
| 1858 | ptr = skb_tail_pointer(skb);
|
| 1859 | for (i = 0; i < len; i++)
|
| 1860 | ptr = hex_byte_pack_upper(ptr, buf[i]);
|
| 1861 | *ptr = 0;
|
| 1862 | skb_put(skb, len << 1);
|
| 1863 | }
|
| 1864 |
|
| 1865 | |
| 1866 | * Format a string of no more than slen characters into the audit buffer,
|
| 1867 | * enclosed in quote marks.
|
| 1868 |
|
| 1869 | void audit_log_n_string(struct audit_buffer *ab, const char *string,
|
| 1870 | size_t slen)
|
| 1871 | {
|
| 1872 | int avail, new_len;
|
| 1873 | unsigned char *ptr;
|
| 1874 | struct sk_buff *skb;
|
| 1875 |
|
| 1876 | if (!ab)
|
| 1877 | return;
|
| 1878 |
|
| 1879 | BUG_ON(!ab->skb);
|
| 1880 | skb = ab->skb;
|
| 1881 | avail = skb_tailroom(skb);
|
| 1882 | new_len = slen + 3;
|
| 1883 | if (new_len > avail) {
|
| 1884 | avail = audit_expand(ab, new_len);
|
| 1885 | if (!avail)
|
| 1886 | return;
|
| 1887 | }
|
| 1888 | ptr = skb_tail_pointer(skb);
|
| 1889 | *ptr++ = '"';
|
| 1890 | memcpy(ptr, string, slen);
|
| 1891 | ptr += slen;
|
| 1892 | *ptr++ = '"';
|
| 1893 | *ptr = 0;
|
| 1894 | skb_put(skb, slen + 2);
|
| 1895 | }
|
| 1896 |
|
| 1897 | |
| 1898 | * audit_string_contains_control - does a string need to be logged in hex
|
| 1899 | * @string: string to be checked
|
| 1900 | * @len: max length of the string to check
|
| 1901 |
|
| 1902 | bool audit_string_contains_control(const char *string, size_t len)
|
| 1903 | {
|
| 1904 | const unsigned char *p;
|
| 1905 | for (p = string; p < (const unsigned char *)string + len; p++) {
|
| 1906 | if (*p == '"' || *p < 0x21 || *p > 0x7e)
|
| 1907 | return true;
|
| 1908 | }
|
| 1909 | return false;
|
| 1910 | }
|
| 1911 |
|
| 1912 | |
| 1913 | * audit_log_n_untrustedstring - log a string that may contain random characters
|
| 1914 | * @ab: audit_buffer
|
| 1915 | * @len: length of string (not including trailing null)
|
| 1916 | * @string: string to be logged
|
| 1917 | *
|
| 1918 | * This code will escape a string that is passed to it if the string
|
| 1919 | * contains a control character, unprintable character, double quote mark,
|
| 1920 | * or a space. Unescaped strings will start and end with a double quote mark.
|
| 1921 | * Strings that are escaped are printed in hex (2 digits per char).
|
| 1922 | *
|
| 1923 | * The caller specifies the number of characters in the string to log, which may
|
| 1924 | * or may not be the entire string.
|
| 1925 |
|
| 1926 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
|
| 1927 | size_t len)
|
| 1928 | {
|
| 1929 | if (audit_string_contains_control(string, len))
|
| 1930 | audit_log_n_hex(ab, string, len);
|
| 1931 | else
|
| 1932 | audit_log_n_string(ab, string, len);
|
| 1933 | }
|
| 1934 |
|
| 1935 | |
| 1936 | * audit_log_untrustedstring - log a string that may contain random characters
|
| 1937 | * @ab: audit_buffer
|
| 1938 | * @string: string to be logged
|
| 1939 | *
|
| 1940 | * Same as audit_log_n_untrustedstring(), except that strlen is used to
|
| 1941 | * determine string length.
|
| 1942 |
|
| 1943 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
|
| 1944 | {
|
| 1945 | audit_log_n_untrustedstring(ab, string, strlen(string));
|
| 1946 | }
|
| 1947 |
|
| 1948 |
|
| 1949 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
|
| 1950 | const struct path *path)
|
| 1951 | {
|
| 1952 | char *p, *pathname;
|
| 1953 |
|
| 1954 | if (prefix)
|
| 1955 | audit_log_format(ab, "%s", prefix);
|
| 1956 |
|
| 1957 |
|
| 1958 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
|
| 1959 | if (!pathname) {
|
| 1960 | audit_log_string(ab, "<no_memory>");
|
| 1961 | return;
|
| 1962 | }
|
| 1963 | p = d_path(path, pathname, PATH_MAX+11);
|
| 1964 | if (IS_ERR(p)) {
|
| 1965 |
|
| 1966 | audit_log_string(ab, "<too_long>");
|
| 1967 | } else
|
| 1968 | audit_log_untrustedstring(ab, p);
|
| 1969 | kfree(pathname);
|
| 1970 | }
|
| 1971 |
|
| 1972 | void audit_log_session_info(struct audit_buffer *ab)
|
| 1973 | {
|
| 1974 | unsigned int sessionid = audit_get_sessionid(current);
|
| 1975 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
|
| 1976 |
|
| 1977 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
|
| 1978 | }
|
| 1979 |
|
| 1980 | void audit_log_key(struct audit_buffer *ab, char *key)
|
| 1981 | {
|
| 1982 | audit_log_format(ab, " key=");
|
| 1983 | if (key)
|
| 1984 | audit_log_untrustedstring(ab, key);
|
| 1985 | else
|
| 1986 | audit_log_format(ab, "(null)");
|
| 1987 | }
|
| 1988 |
|
| 1989 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
|
| 1990 | {
|
| 1991 | int i;
|
| 1992 |
|
| 1993 | audit_log_format(ab, " %s=", prefix);
|
| 1994 | CAP_FOR_EACH_U32(i) {
|
| 1995 | audit_log_format(ab, "%08x",
|
| 1996 | cap->cap[CAP_LAST_U32 - i]);
|
| 1997 | }
|
| 1998 | }
|
| 1999 |
|
| 2000 | static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
|
| 2001 | {
|
| 2002 | kernel_cap_t *perm = &name->fcap.permitted;
|
| 2003 | kernel_cap_t *inh = &name->fcap.inheritable;
|
| 2004 | int log = 0;
|
| 2005 |
|
| 2006 | if (!cap_isclear(*perm)) {
|
| 2007 | audit_log_cap(ab, "cap_fp", perm);
|
| 2008 | log = 1;
|
| 2009 | }
|
| 2010 | if (!cap_isclear(*inh)) {
|
| 2011 | audit_log_cap(ab, "cap_fi", inh);
|
| 2012 | log = 1;
|
| 2013 | }
|
| 2014 |
|
| 2015 | if (log)
|
| 2016 | audit_log_format(ab, " cap_fe=%d cap_fver=%x",
|
| 2017 | name->fcap.fE, name->fcap_ver);
|
| 2018 | }
|
| 2019 |
|
| 2020 | static inline int audit_copy_fcaps(struct audit_names *name,
|
| 2021 | const struct dentry *dentry)
|
| 2022 | {
|
| 2023 | struct cpu_vfs_cap_data caps;
|
| 2024 | int rc;
|
| 2025 |
|
| 2026 | if (!dentry)
|
| 2027 | return 0;
|
| 2028 |
|
| 2029 | rc = get_vfs_caps_from_disk(dentry, &caps);
|
| 2030 | if (rc)
|
| 2031 | return rc;
|
| 2032 |
|
| 2033 | name->fcap.permitted = caps.permitted;
|
| 2034 | name->fcap.inheritable = caps.inheritable;
|
| 2035 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
|
| 2036 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
|
| 2037 | VFS_CAP_REVISION_SHIFT;
|
| 2038 |
|
| 2039 | return 0;
|
| 2040 | }
|
| 2041 |
|
| 2042 |
|
| 2043 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
|
| 2044 | struct inode *inode)
|
| 2045 | {
|
| 2046 | name->ino = inode->i_ino;
|
| 2047 | name->dev = inode->i_sb->s_dev;
|
| 2048 | name->mode = inode->i_mode;
|
| 2049 | name->uid = inode->i_uid;
|
| 2050 | name->gid = inode->i_gid;
|
| 2051 | name->rdev = inode->i_rdev;
|
| 2052 | security_inode_getsecid(inode, &name->osid);
|
| 2053 | audit_copy_fcaps(name, dentry);
|
| 2054 | }
|
| 2055 |
|
| 2056 | |
| 2057 | * audit_log_name - produce AUDIT_PATH record from struct audit_names
|
| 2058 | * @context: audit_context for the task
|
| 2059 | * @n: audit_names structure with reportable details
|
| 2060 | * @path: optional path to report instead of audit_names->name
|
| 2061 | * @record_num: record number to report when handling a list of names
|
| 2062 | * @call_panic: optional pointer to int that will be updated if secid fails
|
| 2063 |
|
| 2064 | void audit_log_name(struct audit_context *context, struct audit_names *n,
|
| 2065 | const struct path *path, int record_num, int *call_panic)
|
| 2066 | {
|
| 2067 | struct audit_buffer *ab;
|
| 2068 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
|
| 2069 | if (!ab)
|
| 2070 | return;
|
| 2071 |
|
| 2072 | audit_log_format(ab, "item=%d", record_num);
|
| 2073 |
|
| 2074 | if (path)
|
| 2075 | audit_log_d_path(ab, " name=", path);
|
| 2076 | else if (n->name) {
|
| 2077 | switch (n->name_len) {
|
| 2078 | case AUDIT_NAME_FULL:
|
| 2079 |
|
| 2080 | audit_log_format(ab, " name=");
|
| 2081 | audit_log_untrustedstring(ab, n->name->name);
|
| 2082 | break;
|
| 2083 | case 0:
|
| 2084 | |
| 2085 | * directory component is the cwd
|
| 2086 | audit_log_d_path(ab, " name=", &context->pwd);
|
| 2087 | break;
|
| 2088 | default:
|
| 2089 |
|
| 2090 | audit_log_format(ab, " name=");
|
| 2091 | audit_log_n_untrustedstring(ab, n->name->name,
|
| 2092 | n->name_len);
|
| 2093 | }
|
| 2094 | } else
|
| 2095 | audit_log_format(ab, " name=(null)");
|
| 2096 |
|
| 2097 | if (n->ino != AUDIT_INO_UNSET)
|
| 2098 | audit_log_format(ab, " inode=%lu"
|
| 2099 | " dev=%02x:%02x mode=%#ho"
|
| 2100 | " ouid=%u ogid=%u rdev=%02x:%02x",
|
| 2101 | n->ino,
|
| 2102 | MAJOR(n->dev),
|
| 2103 | MINOR(n->dev),
|
| 2104 | n->mode,
|
| 2105 | from_kuid(&init_user_ns, n->uid),
|
| 2106 | from_kgid(&init_user_ns, n->gid),
|
| 2107 | MAJOR(n->rdev),
|
| 2108 | MINOR(n->rdev));
|
| 2109 | if (n->osid != 0) {
|
| 2110 | char *ctx = NULL;
|
| 2111 | u32 len;
|
| 2112 | if (security_secid_to_secctx(
|
| 2113 | n->osid, &ctx, &len)) {
|
| 2114 | audit_log_format(ab, " osid=%u", n->osid);
|
| 2115 | if (call_panic)
|
| 2116 | *call_panic = 2;
|
| 2117 | } else {
|
| 2118 | audit_log_format(ab, " obj=%s", ctx);
|
| 2119 | security_release_secctx(ctx, len);
|
| 2120 | }
|
| 2121 | }
|
| 2122 |
|
| 2123 |
|
| 2124 | audit_log_format(ab, " nametype=");
|
| 2125 | switch(n->type) {
|
| 2126 | case AUDIT_TYPE_NORMAL:
|
| 2127 | audit_log_format(ab, "NORMAL");
|
| 2128 | break;
|
| 2129 | case AUDIT_TYPE_PARENT:
|
| 2130 | audit_log_format(ab, "PARENT");
|
| 2131 | break;
|
| 2132 | case AUDIT_TYPE_CHILD_DELETE:
|
| 2133 | audit_log_format(ab, "DELETE");
|
| 2134 | break;
|
| 2135 | case AUDIT_TYPE_CHILD_CREATE:
|
| 2136 | audit_log_format(ab, "CREATE");
|
| 2137 | break;
|
| 2138 | default:
|
| 2139 | audit_log_format(ab, "UNKNOWN");
|
| 2140 | break;
|
| 2141 | }
|
| 2142 |
|
| 2143 | audit_log_fcaps(ab, n);
|
| 2144 | audit_log_end(ab);
|
| 2145 | }
|
| 2146 |
|
| 2147 | int audit_log_task_context(struct audit_buffer *ab)
|
| 2148 | {
|
| 2149 | char *ctx = NULL;
|
| 2150 | unsigned len;
|
| 2151 | int error;
|
| 2152 | u32 sid;
|
| 2153 |
|
| 2154 | security_task_getsecid(current, &sid);
|
| 2155 | if (!sid)
|
| 2156 | return 0;
|
| 2157 |
|
| 2158 | error = security_secid_to_secctx(sid, &ctx, &len);
|
| 2159 | if (error) {
|
| 2160 | if (error != -EINVAL)
|
| 2161 | goto error_path;
|
| 2162 | return 0;
|
| 2163 | }
|
| 2164 |
|
| 2165 | audit_log_format(ab, " subj=%s", ctx);
|
| 2166 | security_release_secctx(ctx, len);
|
| 2167 | return 0;
|
| 2168 |
|
| 2169 | error_path:
|
| 2170 | audit_panic("error in audit_log_task_context");
|
| 2171 | return error;
|
| 2172 | }
|
| 2173 | EXPORT_SYMBOL(audit_log_task_context);
|
| 2174 |
|
| 2175 | void audit_log_d_path_exe(struct audit_buffer *ab,
|
| 2176 | struct mm_struct *mm)
|
| 2177 | {
|
| 2178 | struct file *exe_file;
|
| 2179 |
|
| 2180 | if (!mm)
|
| 2181 | goto out_null;
|
| 2182 |
|
| 2183 | exe_file = get_mm_exe_file(mm);
|
| 2184 | if (!exe_file)
|
| 2185 | goto out_null;
|
| 2186 |
|
| 2187 | audit_log_d_path(ab, " exe=", &exe_file->f_path);
|
| 2188 | fput(exe_file);
|
| 2189 | return;
|
| 2190 | out_null:
|
| 2191 | audit_log_format(ab, " exe=(null)");
|
| 2192 | }
|
| 2193 |
|
| 2194 | struct tty_struct *audit_get_tty(struct task_struct *tsk)
|
| 2195 | {
|
| 2196 | struct tty_struct *tty = NULL;
|
| 2197 | unsigned long flags;
|
| 2198 |
|
| 2199 | spin_lock_irqsave(&tsk->sighand->siglock, flags);
|
| 2200 | if (tsk->signal)
|
| 2201 | tty = tty_kref_get(tsk->signal->tty);
|
| 2202 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
|
| 2203 | return tty;
|
| 2204 | }
|
| 2205 |
|
| 2206 | void audit_put_tty(struct tty_struct *tty)
|
| 2207 | {
|
| 2208 | tty_kref_put(tty);
|
| 2209 | }
|
| 2210 |
|
| 2211 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
|
| 2212 | {
|
| 2213 | const struct cred *cred;
|
| 2214 | char comm[sizeof(tsk->comm)];
|
| 2215 | struct tty_struct *tty;
|
| 2216 |
|
| 2217 | if (!ab)
|
| 2218 | return;
|
| 2219 |
|
| 2220 |
|
| 2221 | cred = current_cred();
|
| 2222 | tty = audit_get_tty(tsk);
|
| 2223 | audit_log_format(ab,
|
| 2224 | " ppid=%d pid=%d auid=%u uid=%u gid=%u"
|
| 2225 | " euid=%u suid=%u fsuid=%u"
|
| 2226 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
|
| 2227 | task_ppid_nr(tsk),
|
| 2228 | task_tgid_nr(tsk),
|
| 2229 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
|
| 2230 | from_kuid(&init_user_ns, cred->uid),
|
| 2231 | from_kgid(&init_user_ns, cred->gid),
|
| 2232 | from_kuid(&init_user_ns, cred->euid),
|
| 2233 | from_kuid(&init_user_ns, cred->suid),
|
| 2234 | from_kuid(&init_user_ns, cred->fsuid),
|
| 2235 | from_kgid(&init_user_ns, cred->egid),
|
| 2236 | from_kgid(&init_user_ns, cred->sgid),
|
| 2237 | from_kgid(&init_user_ns, cred->fsgid),
|
| 2238 | tty ? tty_name(tty) : "(none)",
|
| 2239 | audit_get_sessionid(tsk));
|
| 2240 | audit_put_tty(tty);
|
| 2241 | audit_log_format(ab, " comm=");
|
| 2242 | audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
|
| 2243 | audit_log_d_path_exe(ab, tsk->mm);
|
| 2244 | audit_log_task_context(ab);
|
| 2245 | }
|
| 2246 | EXPORT_SYMBOL(audit_log_task_info);
|
| 2247 |
|
| 2248 | |
| 2249 | * audit_log_link_denied - report a link restriction denial
|
| 2250 | * @operation: specific link operation
|
| 2251 | * @link: the path that triggered the restriction
|
| 2252 |
|
| 2253 | void audit_log_link_denied(const char *operation, const struct path *link)
|
| 2254 | {
|
| 2255 | struct audit_buffer *ab;
|
| 2256 | struct audit_names *name;
|
| 2257 |
|
| 2258 | name = kzalloc(sizeof(*name), GFP_NOFS);
|
| 2259 | if (!name)
|
| 2260 | return;
|
| 2261 |
|
| 2262 |
|
| 2263 | ab = audit_log_start(current->audit_context, GFP_KERNEL,
|
| 2264 | AUDIT_ANOM_LINK);
|
| 2265 | if (!ab)
|
| 2266 | goto out;
|
| 2267 | audit_log_format(ab, "op=%s", operation);
|
| 2268 | audit_log_task_info(ab, current);
|
| 2269 | audit_log_format(ab, " res=0");
|
| 2270 | audit_log_end(ab);
|
| 2271 |
|
| 2272 |
|
| 2273 | name->type = AUDIT_TYPE_NORMAL;
|
| 2274 | audit_copy_inode(name, link->dentry, d_backing_inode(link->dentry));
|
| 2275 | audit_log_name(current->audit_context, name, link, 0, NULL);
|
| 2276 | out:
|
| 2277 | kfree(name);
|
| 2278 | }
|
| 2279 |
|
| 2280 | |
| 2281 | * audit_log_end - end one audit record
|
| 2282 | * @ab: the audit_buffer
|
| 2283 | *
|
| 2284 | * We can not do a netlink send inside an irq context because it blocks (last
|
| 2285 | * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
|
| 2286 | * queue and a tasklet is scheduled to remove them from the queue outside the
|
| 2287 | * irq context. May be called in any context.
|
| 2288 |
|
| 2289 | void audit_log_end(struct audit_buffer *ab)
|
| 2290 | {
|
| 2291 | struct sk_buff *skb;
|
| 2292 | struct nlmsghdr *nlh;
|
| 2293 |
|
| 2294 | if (!ab)
|
| 2295 | return;
|
| 2296 |
|
| 2297 | if (audit_rate_check()) {
|
| 2298 | skb = ab->skb;
|
| 2299 | ab->skb = NULL;
|
| 2300 |
|
| 2301 | |
| 2302 | * kauditd_send_multicast_skb() for length quirks
|
| 2303 | nlh = nlmsg_hdr(skb);
|
| 2304 | nlh->nlmsg_len = skb->len - NLMSG_HDRLEN;
|
| 2305 |
|
| 2306 |
|
| 2307 | skb_queue_tail(&audit_queue, skb);
|
| 2308 | wake_up_interruptible(&kauditd_wait);
|
| 2309 | } else
|
| 2310 | audit_log_lost("rate limit exceeded");
|
| 2311 |
|
| 2312 | audit_buffer_free(ab);
|
| 2313 | }
|
| 2314 |
|
| 2315 | |
| 2316 | * audit_log - Log an audit record
|
| 2317 | * @ctx: audit context
|
| 2318 | * @gfp_mask: type of allocation
|
| 2319 | * @type: audit message type
|
| 2320 | * @fmt: format string to use
|
| 2321 | * @...: variable parameters matching the format string
|
| 2322 | *
|
| 2323 | * This is a convenience function that calls audit_log_start,
|
| 2324 | * audit_log_vformat, and audit_log_end. It may be called
|
| 2325 | * in any context.
|
| 2326 |
|
| 2327 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
|
| 2328 | const char *fmt, ...)
|
| 2329 | {
|
| 2330 | struct audit_buffer *ab;
|
| 2331 | va_list args;
|
| 2332 |
|
| 2333 | ab = audit_log_start(ctx, gfp_mask, type);
|
| 2334 | if (ab) {
|
| 2335 | va_start(args, fmt);
|
| 2336 | audit_log_vformat(ab, fmt, args);
|
| 2337 | va_end(args);
|
| 2338 | audit_log_end(ab);
|
| 2339 | }
|
| 2340 | }
|
| 2341 |
|
| 2342 | #ifdef CONFIG_SECURITY
|
| 2343 | |
| 2344 | * audit_log_secctx - Converts and logs SELinux context
|
| 2345 | * @ab: audit_buffer
|
| 2346 | * @secid: security number
|
| 2347 | *
|
| 2348 | * This is a helper function that calls security_secid_to_secctx to convert
|
| 2349 | * secid to secctx and then adds the (converted) SELinux context to the audit
|
| 2350 | * log by calling audit_log_format, thus also preventing leak of internal secid
|
| 2351 | * to userspace. If secid cannot be converted audit_panic is called.
|
| 2352 |
|
| 2353 | void audit_log_secctx(struct audit_buffer *ab, u32 secid)
|
| 2354 | {
|
| 2355 | u32 len;
|
| 2356 | char *secctx;
|
| 2357 |
|
| 2358 | if (security_secid_to_secctx(secid, &secctx, &len)) {
|
| 2359 | audit_panic("Cannot convert secid to context");
|
| 2360 | } else {
|
| 2361 | audit_log_format(ab, " obj=%s", secctx);
|
| 2362 | security_release_secctx(secctx, len);
|
| 2363 | }
|
| 2364 | }
|
| 2365 | EXPORT_SYMBOL(audit_log_secctx);
|
| 2366 | #endif
|
| 2367 |
|
| 2368 | EXPORT_SYMBOL(audit_log_start);
|
| 2369 | EXPORT_SYMBOL(audit_log_end);
|
| 2370 | EXPORT_SYMBOL(audit_log_format);
|
| 2371 | EXPORT_SYMBOL(audit_log);
|