| /* audit.c -- Auditing support |
| * Gateway between the kernel (e.g., selinux) and the user-space audit daemon. |
| * System-call specific features have moved to auditsc.c |
| * |
| * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina. |
| * All Rights Reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| * |
| * Written by Rickard E. (Rik) Faith <faith@redhat.com> |
| * |
| * Goals: 1) Integrate fully with Security Modules. |
| * 2) Minimal run-time overhead: |
| * a) Minimal when syscall auditing is disabled (audit_enable=0). |
| * b) Small when syscall auditing is enabled and no audit record |
| * is generated (defer as much work as possible to record |
| * generation time): |
| * i) context is allocated, |
| * ii) names from getname are stored without a copy, and |
| * iii) inode information stored from path_lookup. |
| * 3) Ability to disable syscall auditing at boot time (audit=0). |
| * 4) Usable by other parts of the kernel (if audit_log* is called, |
| * then a syscall record will be generated automatically for the |
| * current syscall). |
| * 5) Netlink interface to user-space. |
| * 6) Support low-overhead kernel-based filtering to minimize the |
| * information that must be passed to user-space. |
| * |
| * Example user-space utilities: http://people.redhat.com/sgrubb/audit/ |
| */ |
| |
| #include <linux/init.h> |
| #include <asm/types.h> |
| #include <linux/atomic.h> |
| #include <linux/mm.h> |
| #include <linux/export.h> |
| #include <linux/slab.h> |
| #include <linux/err.h> |
| #include <linux/kthread.h> |
| #include <linux/kernel.h> |
| #include <linux/syscalls.h> |
| |
| #include <linux/audit.h> |
| |
| #include <net/sock.h> |
| #include <net/netlink.h> |
| #include <linux/skbuff.h> |
| #ifdef CONFIG_SECURITY |
| #include <linux/security.h> |
| #endif |
| #include <net/netlink.h> |
| #include <linux/freezer.h> |
| #include <linux/tty.h> |
| #include <linux/pid_namespace.h> |
| |
| #include "audit.h" |
| |
| /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
| * (Initialization happens after skb_init is called.) */ |
| #define AUDIT_DISABLED -1 |
| #define AUDIT_UNINITIALIZED 0 |
| #define AUDIT_INITIALIZED 1 |
| static int audit_initialized; |
| |
| #define AUDIT_OFF 0 |
| #define AUDIT_ON 1 |
| #define AUDIT_LOCKED 2 |
| int audit_enabled; |
| int audit_ever_enabled; |
| |
| EXPORT_SYMBOL_GPL(audit_enabled); |
| |
| /* Default state when kernel boots without any parameters. */ |
| static int audit_default; |
| |
| /* If auditing cannot proceed, audit_failure selects what happens. */ |
| static int audit_failure = AUDIT_FAIL_PRINTK; |
| |
| /* |
| * If audit records are to be written to the netlink socket, audit_pid |
| * contains the pid of the auditd process and audit_nlk_portid contains |
| * the portid to use to send netlink messages to that process. |
| */ |
| int audit_pid; |
| static int audit_nlk_portid; |
| |
| /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
| * to that number per second. This prevents DoS attacks, but results in |
| * audit records being dropped. */ |
| static int audit_rate_limit; |
| |
| /* Number of outstanding audit_buffers allowed. */ |
| static int audit_backlog_limit = 64; |
| static int audit_backlog_wait_time = 60 * HZ; |
| static int audit_backlog_wait_overflow = 0; |
| |
| /* The identity of the user shutting down the audit system. */ |
| kuid_t audit_sig_uid = INVALID_UID; |
| pid_t audit_sig_pid = -1; |
| u32 audit_sig_sid = 0; |
| |
| /* Records can be lost in several ways: |
| 0) [suppressed in audit_alloc] |
| 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] |
| 2) out of memory in audit_log_move [alloc_skb] |
| 3) suppressed due to audit_rate_limit |
| 4) suppressed due to audit_backlog_limit |
| */ |
| static atomic_t audit_lost = ATOMIC_INIT(0); |
| |
| /* The netlink socket. */ |
| static struct sock *audit_sock; |
| |
| /* Hash for inode-based rules */ |
| struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; |
| |
| /* The audit_freelist is a list of pre-allocated audit buffers (if more |
| * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
| * being placed on the freelist). */ |
| static DEFINE_SPINLOCK(audit_freelist_lock); |
| static int audit_freelist_count; |
| static LIST_HEAD(audit_freelist); |
| |
| static struct sk_buff_head audit_skb_queue; |
| /* queue of skbs to send to auditd when/if it comes back */ |
| static struct sk_buff_head audit_skb_hold_queue; |
| static struct task_struct *kauditd_task; |
| static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); |
| static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
| |
| /* Serialize requests from userspace. */ |
| DEFINE_MUTEX(audit_cmd_mutex); |
| |
| /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting |
| * audit records. Since printk uses a 1024 byte buffer, this buffer |
| * should be at least that large. */ |
| #define AUDIT_BUFSIZ 1024 |
| |
| /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the |
| * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ |
| #define AUDIT_MAXFREE (2*NR_CPUS) |
| |
| /* The audit_buffer is used when formatting an audit record. The caller |
| * locks briefly to get the record off the freelist or to allocate the |
| * buffer, and locks briefly to send the buffer to the netlink layer or |
| * to place it on a transmit queue. Multiple audit_buffers can be in |
| * use simultaneously. */ |
| struct audit_buffer { |
| struct list_head list; |
| struct sk_buff *skb; /* formatted skb ready to send */ |
| struct audit_context *ctx; /* NULL or associated context */ |
| gfp_t gfp_mask; |
| }; |
| |
| struct audit_reply { |
| int pid; |
| struct sk_buff *skb; |
| }; |
| |
| static void audit_set_pid(struct audit_buffer *ab, pid_t pid) |
| { |
| if (ab) { |
| struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
| nlh->nlmsg_pid = pid; |
| } |
| } |
| |
| void audit_panic(const char *message) |
| { |
| switch (audit_failure) |
| { |
| case AUDIT_FAIL_SILENT: |
| break; |
| case AUDIT_FAIL_PRINTK: |
| if (printk_ratelimit()) |
| printk(KERN_ERR "audit: %s\n", message); |
| break; |
| case AUDIT_FAIL_PANIC: |
| /* test audit_pid since printk is always losey, why bother? */ |
| if (audit_pid) |
| panic("audit: %s\n", message); |
| break; |
| } |
| } |
| |
| static inline int audit_rate_check(void) |
| { |
| static unsigned long last_check = 0; |
| static int messages = 0; |
| static DEFINE_SPINLOCK(lock); |
| unsigned long flags; |
| unsigned long now; |
| unsigned long elapsed; |
| int retval = 0; |
| |
| if (!audit_rate_limit) return 1; |
| |
| spin_lock_irqsave(&lock, flags); |
| if (++messages < audit_rate_limit) { |
| retval = 1; |
| } else { |
| now = jiffies; |
| elapsed = now - last_check; |
| if (elapsed > HZ) { |
| last_check = now; |
| messages = 0; |
| retval = 1; |
| } |
| } |
| spin_unlock_irqrestore(&lock, flags); |
| |
| return retval; |
| } |
| |
| /** |
| * audit_log_lost - conditionally log lost audit message event |
| * @message: the message stating reason for lost audit message |
| * |
| * Emit at least 1 message per second, even if audit_rate_check is |
| * throttling. |
| * Always increment the lost messages counter. |
| */ |
| void audit_log_lost(const char *message) |
| { |
| static unsigned long last_msg = 0; |
| static DEFINE_SPINLOCK(lock); |
| unsigned long flags; |
| unsigned long now; |
| int print; |
| |
| atomic_inc(&audit_lost); |
| |
| print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); |
| |
| if (!print) { |
| spin_lock_irqsave(&lock, flags); |
| now = jiffies; |
| if (now - last_msg > HZ) { |
| print = 1; |
| last_msg = now; |
| } |
| spin_unlock_irqrestore(&lock, flags); |
| } |
| |
| if (print) { |
| if (printk_ratelimit()) |
| printk(KERN_WARNING |
| "audit: audit_lost=%d audit_rate_limit=%d " |
| "audit_backlog_limit=%d\n", |
| atomic_read(&audit_lost), |
| audit_rate_limit, |
| audit_backlog_limit); |
| audit_panic(message); |
| } |
| } |
| |
| static int audit_log_config_change(char *function_name, int new, int old, |
| int allow_changes) |
| { |
| struct audit_buffer *ab; |
| int rc = 0; |
| |
| ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
| if (unlikely(!ab)) |
| return rc; |
| audit_log_format(ab, "%s=%d old=%d", function_name, new, old); |
| audit_log_session_info(ab); |
| rc = audit_log_task_context(ab); |
| if (rc) |
| allow_changes = 0; /* Something weird, deny request */ |
| audit_log_format(ab, " res=%d", allow_changes); |
| audit_log_end(ab); |
| return rc; |
| } |
| |
| static int audit_do_config_change(char *function_name, int *to_change, int new) |
| { |
| int allow_changes, rc = 0, old = *to_change; |
| |
| /* check if we are locked */ |
| if (audit_enabled == AUDIT_LOCKED) |
| allow_changes = 0; |
| else |
| allow_changes = 1; |
| |
| if (audit_enabled != AUDIT_OFF) { |
| rc = audit_log_config_change(function_name, new, old, allow_changes); |
| if (rc) |
| allow_changes = 0; |
| } |
| |
| /* If we are allowed, make the change */ |
| if (allow_changes == 1) |
| *to_change = new; |
| /* Not allowed, update reason */ |
| else if (rc == 0) |
| rc = -EPERM; |
| return rc; |
| } |
| |
| static int audit_set_rate_limit(int limit) |
| { |
| return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
| } |
| |
| static int audit_set_backlog_limit(int limit) |
| { |
| return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
| } |
| |
| static int audit_set_enabled(int state) |
| { |
| int rc; |
| if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
| return -EINVAL; |
| |
| rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
| if (!rc) |
| audit_ever_enabled |= !!state; |
| |
| return rc; |
| } |
| |
| static int audit_set_failure(int state) |
| { |
| if (state != AUDIT_FAIL_SILENT |
| && state != AUDIT_FAIL_PRINTK |
| && state != AUDIT_FAIL_PANIC) |
| return -EINVAL; |
| |
| return audit_do_config_change("audit_failure", &audit_failure, state); |
| } |
| |
| /* |
| * Queue skbs to be sent to auditd when/if it comes back. These skbs should |
| * already have been sent via prink/syslog and so if these messages are dropped |
| * it is not a huge concern since we already passed the audit_log_lost() |
| * notification and stuff. This is just nice to get audit messages during |
| * boot before auditd is running or messages generated while auditd is stopped. |
| * This only holds messages is audit_default is set, aka booting with audit=1 |
| * or building your kernel that way. |
| */ |
| static void audit_hold_skb(struct sk_buff *skb) |
| { |
| if (audit_default && |
| skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) |
| skb_queue_tail(&audit_skb_hold_queue, skb); |
| else |
| kfree_skb(skb); |
| } |
| |
| /* |
| * For one reason or another this nlh isn't getting delivered to the userspace |
| * audit daemon, just send it to printk. |
| */ |
| static void audit_printk_skb(struct sk_buff *skb) |
| { |
| struct nlmsghdr *nlh = nlmsg_hdr(skb); |
| char *data = nlmsg_data(nlh); |
| |
| if (nlh->nlmsg_type != AUDIT_EOE) { |
| if (printk_ratelimit()) |
| printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); |
| else |
| audit_log_lost("printk limit exceeded\n"); |
| } |
| |
| audit_hold_skb(skb); |
| } |
| |
| static void kauditd_send_skb(struct sk_buff *skb) |
| { |
| int err; |
| /* take a reference in case we can't send it and we want to hold it */ |
| skb_get(skb); |
| err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
| if (err < 0) { |
| BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
| printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
| audit_log_lost("auditd disappeared\n"); |
| audit_pid = 0; |
| /* we might get lucky and get this in the next auditd */ |
| audit_hold_skb(skb); |
| } else |
| /* drop the extra reference if sent ok */ |
| consume_skb(skb); |
| } |
| |
| /* |
| * flush_hold_queue - empty the hold queue if auditd appears |
| * |
| * If auditd just started, drain the queue of messages already |
| * sent to syslog/printk. Remember loss here is ok. We already |
| * called audit_log_lost() if it didn't go out normally. so the |
| * race between the skb_dequeue and the next check for audit_pid |
| * doesn't matter. |
| * |
| * If you ever find kauditd to be too slow we can get a perf win |
| * by doing our own locking and keeping better track if there |
| * are messages in this queue. I don't see the need now, but |
| * in 5 years when I want to play with this again I'll see this |
| * note and still have no friggin idea what i'm thinking today. |
| */ |
| static void flush_hold_queue(void) |
| { |
| struct sk_buff *skb; |
| |
| if (!audit_default || !audit_pid) |
| return; |
| |
| skb = skb_dequeue(&audit_skb_hold_queue); |
| if (likely(!skb)) |
| return; |
| |
| while (skb && audit_pid) { |
| kauditd_send_skb(skb); |
| skb = skb_dequeue(&audit_skb_hold_queue); |
| } |
| |
| /* |
| * if auditd just disappeared but we |
| * dequeued an skb we need to drop ref |
| */ |
| if (skb) |
| consume_skb(skb); |
| } |
| |
| static int kauditd_thread(void *dummy) |
| { |
| set_freezable(); |
| while (!kthread_should_stop()) { |
| struct sk_buff *skb; |
| DECLARE_WAITQUEUE(wait, current); |
| |
| flush_hold_queue(); |
| |
| skb = skb_dequeue(&audit_skb_queue); |
| wake_up(&audit_backlog_wait); |
| if (skb) { |
| if (audit_pid) |
| kauditd_send_skb(skb); |
| else |
| audit_printk_skb(skb); |
| continue; |
| } |
| set_current_state(TASK_INTERRUPTIBLE); |
| add_wait_queue(&kauditd_wait, &wait); |
| |
| if (!skb_queue_len(&audit_skb_queue)) { |
| try_to_freeze(); |
| schedule(); |
| } |
| |
| __set_current_state(TASK_RUNNING); |
| remove_wait_queue(&kauditd_wait, &wait); |
| } |
| return 0; |
| } |
| |
| int audit_send_list(void *_dest) |
| { |
| struct audit_netlink_list *dest = _dest; |
| int pid = dest->pid; |
| struct sk_buff *skb; |
| |
| /* wait for parent to finish and send an ACK */ |
| mutex_lock(&audit_cmd_mutex); |
| mutex_unlock(&audit_cmd_mutex); |
| |
| while ((skb = __skb_dequeue(&dest->q)) != NULL) |
| netlink_unicast(audit_sock, skb, pid, 0); |
| |
| kfree(dest); |
| |
| return 0; |
| } |
| |
| struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, |
| int multi, const void *payload, int size) |
| { |
| struct sk_buff *skb; |
| struct nlmsghdr *nlh; |
| void *data; |
| int flags = multi ? NLM_F_MULTI : 0; |
| int t = done ? NLMSG_DONE : type; |
| |
| skb = nlmsg_new(size, GFP_KERNEL); |
| if (!skb) |
| return NULL; |
| |
| nlh = nlmsg_put(skb, pid, seq, t, size, flags); |
| if (!nlh) |
| goto out_kfree_skb; |
| data = nlmsg_data(nlh); |
| memcpy(data, payload, size); |
| return skb; |
| |
| out_kfree_skb: |
| kfree_skb(skb); |
| return NULL; |
| } |
| |
| static int audit_send_reply_thread(void *arg) |
| { |
| struct audit_reply *reply = (struct audit_reply *)arg; |
| |
| mutex_lock(&audit_cmd_mutex); |
| mutex_unlock(&audit_cmd_mutex); |
| |
| /* Ignore failure. It'll only happen if the sender goes away, |
| because our timeout is set to infinite. */ |
| netlink_unicast(audit_sock, reply->skb, reply->pid, 0); |
| kfree(reply); |
| return 0; |
| } |
| /** |
| * audit_send_reply - send an audit reply message via netlink |
| * @pid: process id to send reply to |
| * @seq: sequence number |
| * @type: audit message type |
| * @done: done (last) flag |
| * @multi: multi-part message flag |
| * @payload: payload data |
| * @size: payload size |
| * |
| * Allocates an skb, builds the netlink message, and sends it to the pid. |
| * No failure notifications. |
| */ |
| static void audit_send_reply(int pid, int seq, int type, int done, int multi, |
| const void *payload, int size) |
| { |
| struct sk_buff *skb; |
| struct task_struct *tsk; |
| struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), |
| GFP_KERNEL); |
| |
| if (!reply) |
| return; |
| |
| skb = audit_make_reply(pid, seq, type, done, multi, payload, size); |
| if (!skb) |
| goto out; |
| |
| reply->pid = pid; |
| reply->skb = skb; |
| |
| tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); |
| if (!IS_ERR(tsk)) |
| return; |
| kfree_skb(skb); |
| out: |
| kfree(reply); |
| } |
| |
| /* |
| * Check for appropriate CAP_AUDIT_ capabilities on incoming audit |
| * control messages. |
| */ |
| static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
| { |
| int err = 0; |
| |
| /* Only support the initial namespaces for now. */ |
| if ((current_user_ns() != &init_user_ns) || |
| (task_active_pid_ns(current) != &init_pid_ns)) |
| return -EPERM; |
| |
| switch (msg_type) { |
| case AUDIT_LIST: |
| case AUDIT_ADD: |
| case AUDIT_DEL: |
| return -EOPNOTSUPP; |
| case AUDIT_GET: |
| case AUDIT_SET: |
| case AUDIT_LIST_RULES: |
| case AUDIT_ADD_RULE: |
| case AUDIT_DEL_RULE: |
| case AUDIT_SIGNAL_INFO: |
| case AUDIT_TTY_GET: |
| case AUDIT_TTY_SET: |
| case AUDIT_TRIM: |
| case AUDIT_MAKE_EQUIV: |
| if (!capable(CAP_AUDIT_CONTROL)) |
| err = -EPERM; |
| break; |
| case AUDIT_USER: |
| case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
| case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: |
| if (!capable(CAP_AUDIT_WRITE)) |
| err = -EPERM; |
| break; |
| default: /* bad msg */ |
| err = -EINVAL; |
| } |
| |
| return err; |
| } |
| |
| static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
| { |
| int rc = 0; |
| uid_t uid = from_kuid(&init_user_ns, current_uid()); |
| |
| if (!audit_enabled) { |
| *ab = NULL; |
| return rc; |
| } |
| |
| *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); |
| if (unlikely(!*ab)) |
| return rc; |
| audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid); |
| audit_log_session_info(*ab); |
| audit_log_task_context(*ab); |
| |
| return rc; |
| } |
| |
| static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
| { |
| u32 seq; |
| void *data; |
| struct audit_status *status_get, status_set; |
| int err; |
| struct audit_buffer *ab; |
| u16 msg_type = nlh->nlmsg_type; |
| struct audit_sig_info *sig_data; |
| char *ctx = NULL; |
| u32 len; |
| |
| err = audit_netlink_ok(skb, msg_type); |
| if (err) |
| return err; |
| |
| /* As soon as there's any sign of userspace auditd, |
| * start kauditd to talk to it */ |
| if (!kauditd_task) { |
| kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
| if (IS_ERR(kauditd_task)) { |
| err = PTR_ERR(kauditd_task); |
| kauditd_task = NULL; |
| return err; |
| } |
| } |
| seq = nlh->nlmsg_seq; |
| data = nlmsg_data(nlh); |
| |
| switch (msg_type) { |
| case AUDIT_GET: |
| status_set.enabled = audit_enabled; |
| status_set.failure = audit_failure; |
| status_set.pid = audit_pid; |
| status_set.rate_limit = audit_rate_limit; |
| status_set.backlog_limit = audit_backlog_limit; |
| status_set.lost = atomic_read(&audit_lost); |
| status_set.backlog = skb_queue_len(&audit_skb_queue); |
| audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, |
| &status_set, sizeof(status_set)); |
| break; |
| case AUDIT_SET: |
| if (nlh->nlmsg_len < sizeof(struct audit_status)) |
| return -EINVAL; |
| status_get = (struct audit_status *)data; |
| if (status_get->mask & AUDIT_STATUS_ENABLED) { |
| err = audit_set_enabled(status_get->enabled); |
| if (err < 0) |
| return err; |
| } |
| if (status_get->mask & AUDIT_STATUS_FAILURE) { |
| err = audit_set_failure(status_get->failure); |
| if (err < 0) |
| return err; |
| } |
| if (status_get->mask & AUDIT_STATUS_PID) { |
| int new_pid = status_get->pid; |
| |
| if (audit_enabled != AUDIT_OFF) |
| audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
| audit_pid = new_pid; |
| audit_nlk_portid = NETLINK_CB(skb).portid; |
| } |
| if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { |
| err = audit_set_rate_limit(status_get->rate_limit); |
| if (err < 0) |
| return err; |
| } |
| if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
| err = audit_set_backlog_limit(status_get->backlog_limit); |
| break; |
| case AUDIT_USER: |
| case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
| case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: |
| if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
| return 0; |
| |
| err = audit_filter_user(msg_type); |
| if (err == 1) { |
| err = 0; |
| if (msg_type == AUDIT_USER_TTY) { |
| err = tty_audit_push_current(); |
| if (err) |
| break; |
| } |
| audit_log_common_recv_msg(&ab, msg_type); |
| if (msg_type != AUDIT_USER_TTY) |
| audit_log_format(ab, " msg='%.1024s'", |
| (char *)data); |
| else { |
| int size; |
| |
| audit_log_format(ab, " data="); |
| size = nlmsg_len(nlh); |
| if (size > 0 && |
| ((unsigned char *)data)[size - 1] == '\0') |
| size--; |
| audit_log_n_untrustedstring(ab, data, size); |
| } |
| audit_set_pid(ab, NETLINK_CB(skb).portid); |
| audit_log_end(ab); |
| } |
| break; |
| case AUDIT_ADD_RULE: |
| case AUDIT_DEL_RULE: |
| if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) |
| return -EINVAL; |
| if (audit_enabled == AUDIT_LOCKED) { |
| audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
| audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); |
| audit_log_end(ab); |
| return -EPERM; |
| } |
| /* fallthrough */ |
| case AUDIT_LIST_RULES: |
| err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, |
| seq, data, nlmsg_len(nlh)); |
| break; |
| case AUDIT_TRIM: |
| audit_trim_trees(); |
| audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
| audit_log_format(ab, " op=trim res=1"); |
| audit_log_end(ab); |
| break; |
| case AUDIT_MAKE_EQUIV: { |
| void *bufp = data; |
| u32 sizes[2]; |
| size_t msglen = nlmsg_len(nlh); |
| char *old, *new; |
| |
| err = -EINVAL; |
| if (msglen < 2 * sizeof(u32)) |
| break; |
| memcpy(sizes, bufp, 2 * sizeof(u32)); |
| bufp += 2 * sizeof(u32); |
| msglen -= 2 * sizeof(u32); |
| old = audit_unpack_string(&bufp, &msglen, sizes[0]); |
| if (IS_ERR(old)) { |
| err = PTR_ERR(old); |
| break; |
| } |
| new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
| if (IS_ERR(new)) { |
| err = PTR_ERR(new); |
| kfree(old); |
| break; |
| } |
| /* OK, here comes... */ |
| err = audit_tag_tree(old, new); |
| |
| audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
| |
| audit_log_format(ab, " op=make_equiv old="); |
| audit_log_untrustedstring(ab, old); |
| audit_log_format(ab, " new="); |
| audit_log_untrustedstring(ab, new); |
| audit_log_format(ab, " res=%d", !err); |
| audit_log_end(ab); |
| kfree(old); |
| kfree(new); |
| break; |
| } |
| case AUDIT_SIGNAL_INFO: |
| len = 0; |
| if (audit_sig_sid) { |
| err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); |
| if (err) |
| return err; |
| } |
| sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
| if (!sig_data) { |
| if (audit_sig_sid) |
| security_release_secctx(ctx, len); |
| return -ENOMEM; |
| } |
| sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
| sig_data->pid = audit_sig_pid; |
| if (audit_sig_sid) { |
| memcpy(sig_data->ctx, ctx, len); |
| security_release_secctx(ctx, len); |
| } |
| audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO, |
| 0, 0, sig_data, sizeof(*sig_data) + len); |
| kfree(sig_data); |
| break; |
| case AUDIT_TTY_GET: { |
| struct audit_tty_status s; |
| struct task_struct *tsk = current; |
| |
| spin_lock(&tsk->sighand->siglock); |
| s.enabled = tsk->signal->audit_tty != 0; |
| s.log_passwd = tsk->signal->audit_tty_log_passwd; |
| spin_unlock(&tsk->sighand->siglock); |
| |
| audit_send_reply(NETLINK_CB(skb).portid, seq, |
| AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
| break; |
| } |
| case AUDIT_TTY_SET: { |
| struct audit_tty_status s; |
| struct task_struct *tsk = current; |
| |
| memset(&s, 0, sizeof(s)); |
| /* guard against past and future API changes */ |
| memcpy(&s, data, min(sizeof(s), (size_t)nlh->nlmsg_len)); |
| if ((s.enabled != 0 && s.enabled != 1) || |
| (s.log_passwd != 0 && s.log_passwd != 1)) |
| return -EINVAL; |
| |
| spin_lock(&tsk->sighand->siglock); |
| tsk->signal->audit_tty = s.enabled; |
| tsk->signal->audit_tty_log_passwd = s.log_passwd; |
| spin_unlock(&tsk->sighand->siglock); |
| break; |
| } |
| default: |
| err = -EINVAL; |
| break; |
| } |
| |
| return err < 0 ? err : 0; |
| } |
| |
| /* |
| * Get message from skb. Each message is processed by audit_receive_msg. |
| * Malformed skbs with wrong length are discarded silently. |
| */ |
| static void audit_receive_skb(struct sk_buff *skb) |
| { |
| struct nlmsghdr *nlh; |
| /* |
| * len MUST be signed for nlmsg_next to be able to dec it below 0 |
| * if the nlmsg_len was not aligned |
| */ |
| int len; |
| int err; |
| |
| nlh = nlmsg_hdr(skb); |
| len = skb->len; |
| |
| while (nlmsg_ok(nlh, len)) { |
| err = audit_receive_msg(skb, nlh); |
| /* if err or if this message says it wants a response */ |
| if (err || (nlh->nlmsg_flags & NLM_F_ACK)) |
| netlink_ack(skb, nlh, err); |
| |
| nlh = nlmsg_next(nlh, &len); |
| } |
| } |
| |
| /* Receive messages from netlink socket. */ |
| static void audit_receive(struct sk_buff *skb) |
| { |
| mutex_lock(&audit_cmd_mutex); |
| audit_receive_skb(skb); |
| mutex_unlock(&audit_cmd_mutex); |
| } |
| |
| /* Initialize audit support at boot time. */ |
| static int __init audit_init(void) |
| { |
| int i; |
| struct netlink_kernel_cfg cfg = { |
| .input = audit_receive, |
| }; |
| |
| if (audit_initialized == AUDIT_DISABLED) |
| return 0; |
| |
| printk(KERN_INFO "audit: initializing netlink socket (%s)\n", |
| audit_default ? "enabled" : "disabled"); |
| audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, &cfg); |
| if (!audit_sock) |
| audit_panic("cannot initialize netlink socket"); |
| else |
| audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; |
| |
| skb_queue_head_init(&audit_skb_queue); |
| skb_queue_head_init(&audit_skb_hold_queue); |
| audit_initialized = AUDIT_INITIALIZED; |
| audit_enabled = audit_default; |
| audit_ever_enabled |= !!audit_default; |
| |
| audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
| |
| for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
| INIT_LIST_HEAD(&audit_inode_hash[i]); |
| |
| return 0; |
| } |
| __initcall(audit_init); |
| |
| /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ |
| static int __init audit_enable(char *str) |
| { |
| audit_default = !!simple_strtol(str, NULL, 0); |
| if (!audit_default) |
| audit_initialized = AUDIT_DISABLED; |
| |
| printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled"); |
| |
| if (audit_initialized == AUDIT_INITIALIZED) { |
| audit_enabled = audit_default; |
| audit_ever_enabled |= !!audit_default; |
| } else if (audit_initialized == AUDIT_UNINITIALIZED) { |
| printk(" (after initialization)"); |
| } else { |
| printk(" (until reboot)"); |
| } |
| printk("\n"); |
| |
| return 1; |
| } |
| |
| __setup("audit=", audit_enable); |
| |
| static void audit_buffer_free(struct audit_buffer *ab) |
| { |
| unsigned long flags; |
| |
| if (!ab) |
| return; |
| |
| if (ab->skb) |
| kfree_skb(ab->skb); |
| |
| spin_lock_irqsave(&audit_freelist_lock, flags); |
| if (audit_freelist_count > AUDIT_MAXFREE) |
| kfree(ab); |
| else { |
| audit_freelist_count++; |
| list_add(&ab->list, &audit_freelist); |
| } |
| spin_unlock_irqrestore(&audit_freelist_lock, flags); |
| } |
| |
| static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
| gfp_t gfp_mask, int type) |
| { |
| unsigned long flags; |
| struct audit_buffer *ab = NULL; |
| struct nlmsghdr *nlh; |
| |
| spin_lock_irqsave(&audit_freelist_lock, flags); |
| if (!list_empty(&audit_freelist)) { |
| ab = list_entry(audit_freelist.next, |
| struct audit_buffer, list); |
| list_del(&ab->list); |
| --audit_freelist_count; |
| } |
| spin_unlock_irqrestore(&audit_freelist_lock, flags); |
| |
| if (!ab) { |
| ab = kmalloc(sizeof(*ab), gfp_mask); |
| if (!ab) |
| goto err; |
| } |
| |
| ab->ctx = ctx; |
| ab->gfp_mask = gfp_mask; |
| |
| ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); |
| if (!ab->skb) |
| goto err; |
| |
| nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
| if (!nlh) |
| goto out_kfree_skb; |
| |
| return ab; |
| |
| out_kfree_skb: |
| kfree_skb(ab->skb); |
| ab->skb = NULL; |
| err: |
| audit_buffer_free(ab); |
| return NULL; |
| } |
| |
| /** |
| * audit_serial - compute a serial number for the audit record |
| * |
| * Compute a serial number for the audit record. Audit records are |
| * written to user-space as soon as they are generated, so a complete |
| * audit record may be written in several pieces. The timestamp of the |
| * record and this serial number are used by the user-space tools to |
| * determine which pieces belong to the same audit record. The |
| * (timestamp,serial) tuple is unique for each syscall and is live from |
| * syscall entry to syscall exit. |
| * |
| * NOTE: Another possibility is to store the formatted records off the |
| * audit context (for those records that have a context), and emit them |
| * all at syscall exit. However, this could delay the reporting of |
| * significant errors until syscall exit (or never, if the system |
| * halts). |
| */ |
| unsigned int audit_serial(void) |
| { |
| static DEFINE_SPINLOCK(serial_lock); |
| static unsigned int serial = 0; |
| |
| unsigned long flags; |
| unsigned int ret; |
| |
| spin_lock_irqsave(&serial_lock, flags); |
| do { |
| ret = ++serial; |
| } while (unlikely(!ret)); |
| spin_unlock_irqrestore(&serial_lock, flags); |
| |
| return ret; |
| } |
| |
| static inline void audit_get_stamp(struct audit_context *ctx, |
| struct timespec *t, unsigned int *serial) |
| { |
| if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
| *t = CURRENT_TIME; |
| *serial = audit_serial(); |
| } |
| } |
| |
| /* |
| * Wait for auditd to drain the queue a little |
| */ |
| static void wait_for_auditd(unsigned long sleep_time) |
| { |
| DECLARE_WAITQUEUE(wait, current); |
| set_current_state(TASK_INTERRUPTIBLE); |
| add_wait_queue(&audit_backlog_wait, &wait); |
| |
| if (audit_backlog_limit && |
| skb_queue_len(&audit_skb_queue) > audit_backlog_limit) |
| schedule_timeout(sleep_time); |
| |
| __set_current_state(TASK_RUNNING); |
| remove_wait_queue(&audit_backlog_wait, &wait); |
| } |
| |
| /* Obtain an audit buffer. This routine does locking to obtain the |
| * audit buffer, but then no locking is required for calls to |
| * audit_log_*format. If the tsk is a task that is currently in a |
| * syscall, then the syscall is marked as auditable and an audit record |
| * will be written at syscall exit. If there is no associated task, tsk |
| * should be NULL. */ |
| |
| /** |
| * audit_log_start - obtain an audit buffer |
| * @ctx: audit_context (may be NULL) |
| * @gfp_mask: type of allocation |
| * @type: audit message type |
| * |
| * Returns audit_buffer pointer on success or NULL on error. |
| * |
| * Obtain an audit buffer. This routine does locking to obtain the |
| * audit buffer, but then no locking is required for calls to |
| * audit_log_*format. If the task (ctx) is a task that is currently in a |
| * syscall, then the syscall is marked as auditable and an audit record |
| * will be written at syscall exit. If there is no associated task, then |
| * task context (ctx) should be NULL. |
| */ |
| struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
| int type) |
| { |
| struct audit_buffer *ab = NULL; |
| struct timespec t; |
| unsigned int uninitialized_var(serial); |
| int reserve; |
| unsigned long timeout_start = jiffies; |
| |
| if (audit_initialized != AUDIT_INITIALIZED) |
| return NULL; |
| |
| if (unlikely(audit_filter_type(type))) |
| return NULL; |
| |
| if (gfp_mask & __GFP_WAIT) |
| reserve = 0; |
| else |
| reserve = 5; /* Allow atomic callers to go up to five |
| entries over the normal backlog limit */ |
| |
| while (audit_backlog_limit |
| && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { |
| if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { |
| unsigned long sleep_time; |
| |
| sleep_time = timeout_start + audit_backlog_wait_time - |
| jiffies; |
| if ((long)sleep_time > 0) |
| wait_for_auditd(sleep_time); |
| continue; |
| } |
| if (audit_rate_check() && printk_ratelimit()) |
| printk(KERN_WARNING |
| "audit: audit_backlog=%d > " |
| "audit_backlog_limit=%d\n", |
| skb_queue_len(&audit_skb_queue), |
| audit_backlog_limit); |
| audit_log_lost("backlog limit exceeded"); |
| audit_backlog_wait_time = audit_backlog_wait_overflow; |
| wake_up(&audit_backlog_wait); |
| return NULL; |
| } |
| |
| ab = audit_buffer_alloc(ctx, gfp_mask, type); |
| if (!ab) { |
| audit_log_lost("out of memory in audit_log_start"); |
| return NULL; |
| } |
| |
| audit_get_stamp(ab->ctx, &t, &serial); |
| |
| audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
| t.tv_sec, t.tv_nsec/1000000, serial); |
| return ab; |
| } |
| |
| /** |
| * audit_expand - expand skb in the audit buffer |
| * @ab: audit_buffer |
| * @extra: space to add at tail of the skb |
| * |
| * Returns 0 (no space) on failed expansion, or available space if |
| * successful. |
| */ |
| static inline int audit_expand(struct audit_buffer *ab, int extra) |
| { |
| struct sk_buff *skb = ab->skb; |
| int oldtail = skb_tailroom(skb); |
| int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); |
| int newtail = skb_tailroom(skb); |
| |
| if (ret < 0) { |
| audit_log_lost("out of memory in audit_expand"); |
| return 0; |
| } |
| |
| skb->truesize += newtail - oldtail; |
| return newtail; |
| } |
| |
| /* |
| * Format an audit message into the audit buffer. If there isn't enough |
| * room in the audit buffer, more room will be allocated and vsnprint |
| * will be called a second time. Currently, we assume that a printk |
| * can't format message larger than 1024 bytes, so we don't either. |
| */ |
| static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
| va_list args) |
| { |
| int len, avail; |
| struct sk_buff *skb; |
| va_list args2; |
| |
| if (!ab) |
| return; |
| |
| BUG_ON(!ab->skb); |
| skb = ab->skb; |
| avail = skb_tailroom(skb); |
| if (avail == 0) { |
| avail = audit_expand(ab, AUDIT_BUFSIZ); |
| if (!avail) |
| goto out; |
| } |
| va_copy(args2, args); |
| len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
| if (len >= avail) { |
| /* The printk buffer is 1024 bytes long, so if we get |
| * here and AUDIT_BUFSIZ is at least 1024, then we can |
| * log everything that printk could have logged. */ |
| avail = audit_expand(ab, |
| max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); |
| if (!avail) |
| goto out_va_end; |
| len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
| } |
| if (len > 0) |
| skb_put(skb, len); |
| out_va_end: |
| va_end(args2); |
| out: |
| return; |
| } |
| |
| /** |
| * audit_log_format - format a message into the audit buffer. |
| * @ab: audit_buffer |
| * @fmt: format string |
| * @...: optional parameters matching @fmt string |
| * |
| * All the work is done in audit_log_vformat. |
| */ |
| void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
| { |
| va_list args; |
| |
| if (!ab) |
| return; |
| va_start(args, fmt); |
| audit_log_vformat(ab, fmt, args); |
| va_end(args); |
| } |
| |
| /** |
| * audit_log_hex - convert a buffer to hex and append it to the audit skb |
| * @ab: the audit_buffer |
| * @buf: buffer to convert to hex |
| * @len: length of @buf to be converted |
| * |
| * No return value; failure to expand is silently ignored. |
| * |
| * This function will take the passed buf and convert it into a string of |
| * ascii hex digits. The new string is placed onto the skb. |
| */ |
| void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
| size_t len) |
| { |
| int i, avail, new_len; |
| unsigned char *ptr; |
| struct sk_buff *skb; |
| static const unsigned char *hex = "0123456789ABCDEF"; |
| |
| if (!ab) |
| return; |
| |
| BUG_ON(!ab->skb); |
| skb = ab->skb; |
| avail = skb_tailroom(skb); |
| new_len = len<<1; |
| if (new_len >= avail) { |
| /* Round the buffer request up to the next multiple */ |
| new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); |
| avail = audit_expand(ab, new_len); |
| if (!avail) |
| return; |
| } |
| |
| ptr = skb_tail_pointer(skb); |
| for (i=0; i<len; i++) { |
| *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ |
| *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ |
| } |
| *ptr = 0; |
| skb_put(skb, len << 1); /* new string is twice the old string */ |
| } |
| |
| /* |
| * Format a string of no more than slen characters into the audit buffer, |
| * enclosed in quote marks. |
| */ |
| void audit_log_n_string(struct audit_buffer *ab, const char *string, |
| size_t slen) |
| { |
| int avail, new_len; |
| unsigned char *ptr; |
| struct sk_buff *skb; |
| |
| if (!ab) |
| return; |
| |
| BUG_ON(!ab->skb); |
| skb = ab->skb; |
| avail = skb_tailroom(skb); |
| new_len = slen + 3; /* enclosing quotes + null terminator */ |
| if (new_len > avail) { |
| avail = audit_expand(ab, new_len); |
| if (!avail) |
| return; |
| } |
| ptr = skb_tail_pointer(skb); |
| *ptr++ = '"'; |
| memcpy(ptr, string, slen); |
| ptr += slen; |
| *ptr++ = '"'; |
| *ptr = 0; |
| skb_put(skb, slen + 2); /* don't include null terminator */ |
| } |
| |
| /** |
| * audit_string_contains_control - does a string need to be logged in hex |
| * @string: string to be checked |
| * @len: max length of the string to check |
| */ |
| int audit_string_contains_control(const char *string, size_t len) |
| { |
| const unsigned char *p; |
| for (p = string; p < (const unsigned char *)string + len; p++) { |
| if (*p == '"' || *p < 0x21 || *p > 0x7e) |
| return 1; |
| } |
| return 0; |
| } |
| |
| /** |
| * audit_log_n_untrustedstring - log a string that may contain random characters |
| * @ab: audit_buffer |
| * @len: length of string (not including trailing null) |
| * @string: string to be logged |
| * |
| * This code will escape a string that is passed to it if the string |
| * contains a control character, unprintable character, double quote mark, |
| * or a space. Unescaped strings will start and end with a double quote mark. |
| * Strings that are escaped are printed in hex (2 digits per char). |
| * |
| * The caller specifies the number of characters in the string to log, which may |
| * or may not be the entire string. |
| */ |
| void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
| size_t len) |
| { |
| if (audit_string_contains_control(string, len)) |
| audit_log_n_hex(ab, string, len); |
| else |
| audit_log_n_string(ab, string, len); |
| } |
| |
| /** |
| * audit_log_untrustedstring - log a string that may contain random characters |
| * @ab: audit_buffer |
| * @string: string to be logged |
| * |
| * Same as audit_log_n_untrustedstring(), except that strlen is used to |
| * determine string length. |
| */ |
| void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
| { |
| audit_log_n_untrustedstring(ab, string, strlen(string)); |
| } |
| |
| /* This is a helper-function to print the escaped d_path */ |
| void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
| const struct path *path) |
| { |
| char *p, *pathname; |
| |
| if (prefix) |
| audit_log_format(ab, "%s", prefix); |
| |
| /* We will allow 11 spaces for ' (deleted)' to be appended */ |
| pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
| if (!pathname) { |
| audit_log_string(ab, "<no_memory>"); |
| return; |
| } |
| p = d_path(path, pathname, PATH_MAX+11); |
| if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
| /* FIXME: can we save some information here? */ |
| audit_log_string(ab, "<too_long>"); |
| } else |
| audit_log_untrustedstring(ab, p); |
| kfree(pathname); |
| } |
| |
| void audit_log_session_info(struct audit_buffer *ab) |
| { |
| u32 sessionid = audit_get_sessionid(current); |
| uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); |
| |
| audit_log_format(ab, " auid=%u ses=%u\n", auid, sessionid); |
| } |
| |
| void audit_log_key(struct audit_buffer *ab, char *key) |
| { |
| audit_log_format(ab, " key="); |
| if (key) |
| audit_log_untrustedstring(ab, key); |
| else |
| audit_log_format(ab, "(null)"); |
| } |
| |
| void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
| { |
| int i; |
| |
| audit_log_format(ab, " %s=", prefix); |
| CAP_FOR_EACH_U32(i) { |
| audit_log_format(ab, "%08x", |
| cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); |
| } |
| } |
| |
| void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) |
| { |
| kernel_cap_t *perm = &name->fcap.permitted; |
| kernel_cap_t *inh = &name->fcap.inheritable; |
| int log = 0; |
| |
| if (!cap_isclear(*perm)) { |
| audit_log_cap(ab, "cap_fp", perm); |
| log = 1; |
| } |
| if (!cap_isclear(*inh)) { |
| audit_log_cap(ab, "cap_fi", inh); |
| log = 1; |
| } |
| |
| if (log) |
| audit_log_format(ab, " cap_fe=%d cap_fver=%x", |
| name->fcap.fE, name->fcap_ver); |
| } |
| |
| static inline int audit_copy_fcaps(struct audit_names *name, |
| const struct dentry *dentry) |
| { |
| struct cpu_vfs_cap_data caps; |
| int rc; |
| |
| if (!dentry) |
| return 0; |
| |
| rc = get_vfs_caps_from_disk(dentry, &caps); |
| if (rc) |
| return rc; |
| |
| name->fcap.permitted = caps.permitted; |
| name->fcap.inheritable = caps.inheritable; |
| name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); |
| name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> |
| VFS_CAP_REVISION_SHIFT; |
| |
| return 0; |
| } |
| |
| /* Copy inode data into an audit_names. */ |
| void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, |
| const struct inode *inode) |
| { |
| name->ino = inode->i_ino; |
| name->dev = inode->i_sb->s_dev; |
| name->mode = inode->i_mode; |
| name->uid = inode->i_uid; |
| name->gid = inode->i_gid; |
| name->rdev = inode->i_rdev; |
| security_inode_getsecid(inode, &name->osid); |
| audit_copy_fcaps(name, dentry); |
| } |
| |
| /** |
| * audit_log_name - produce AUDIT_PATH record from struct audit_names |
| * @context: audit_context for the task |
| * @n: audit_names structure with reportable details |
| * @path: optional path to report instead of audit_names->name |
| * @record_num: record number to report when handling a list of names |
| * @call_panic: optional pointer to int that will be updated if secid fails |
| */ |
| void audit_log_name(struct audit_context *context, struct audit_names *n, |
| struct path *path, int record_num, int *call_panic) |
| { |
| struct audit_buffer *ab; |
| ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); |
| if (!ab) |
| return; |
| |
| audit_log_format(ab, "item=%d", record_num); |
| |
| if (path) |
| audit_log_d_path(ab, " name=", path); |
| else if (n->name) { |
| switch (n->name_len) { |
| case AUDIT_NAME_FULL: |
| /* log the full path */ |
| audit_log_format(ab, " name="); |
| audit_log_untrustedstring(ab, n->name->name); |
| break; |
| case 0: |
| /* name was specified as a relative path and the |
| * directory component is the cwd */ |
| audit_log_d_path(ab, " name=", &context->pwd); |
| break; |
| default: |
| /* log the name's directory component */ |
| audit_log_format(ab, " name="); |
| audit_log_n_untrustedstring(ab, n->name->name, |
| n->name_len); |
| } |
| } else |
| audit_log_format(ab, " name=(null)"); |
| |
| if (n->ino != (unsigned long)-1) { |
| audit_log_format(ab, " inode=%lu" |
| " dev=%02x:%02x mode=%#ho" |
| " ouid=%u ogid=%u rdev=%02x:%02x", |
| n->ino, |
| MAJOR(n->dev), |
| MINOR(n->dev), |
| n->mode, |
| from_kuid(&init_user_ns, n->uid), |
| from_kgid(&init_user_ns, n->gid), |
| MAJOR(n->rdev), |
| MINOR(n->rdev)); |
| } |
| if (n->osid != 0) { |
| char *ctx = NULL; |
| u32 len; |
| if (security_secid_to_secctx( |
| n->osid, &ctx, &len)) { |
| audit_log_format(ab, " osid=%u", n->osid); |
| if (call_panic) |
| *call_panic = 2; |
| } else { |
| audit_log_format(ab, " obj=%s", ctx); |
| security_release_secctx(ctx, len); |
| } |
| } |
| |
| audit_log_fcaps(ab, n); |
| audit_log_end(ab); |
| } |
| |
| int audit_log_task_context(struct audit_buffer *ab) |
| { |
| char *ctx = NULL; |
| unsigned len; |
| int error; |
| u32 sid; |
| |
| security_task_getsecid(current, &sid); |
| if (!sid) |
| return 0; |
| |
| error = security_secid_to_secctx(sid, &ctx, &len); |
| if (error) { |
| if (error != -EINVAL) |
| goto error_path; |
| return 0; |
| } |
| |
| audit_log_format(ab, " subj=%s", ctx); |
| security_release_secctx(ctx, len); |
| return 0; |
| |
| error_path: |
| audit_panic("error in audit_log_task_context"); |
| return error; |
| } |
| EXPORT_SYMBOL(audit_log_task_context); |
| |
| void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) |
| { |
| const struct cred *cred; |
| char name[sizeof(tsk->comm)]; |
| struct mm_struct *mm = tsk->mm; |
| char *tty; |
| |
| if (!ab) |
| return; |
| |
| /* tsk == current */ |
| cred = current_cred(); |
| |
| spin_lock_irq(&tsk->sighand->siglock); |
| if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) |
| tty = tsk->signal->tty->name; |
| else |
| tty = "(none)"; |
| spin_unlock_irq(&tsk->sighand->siglock); |
| |
| audit_log_format(ab, |
| " ppid=%ld pid=%d auid=%u uid=%u gid=%u" |
| " euid=%u suid=%u fsuid=%u" |
| " egid=%u sgid=%u fsgid=%u ses=%u tty=%s", |
| sys_getppid(), |
| tsk->pid, |
| from_kuid(&init_user_ns, audit_get_loginuid(tsk)), |
| from_kuid(&init_user_ns, cred->uid), |
| from_kgid(&init_user_ns, cred->gid), |
| from_kuid(&init_user_ns, cred->euid), |
| from_kuid(&init_user_ns, cred->suid), |
| from_kuid(&init_user_ns, cred->fsuid), |
| from_kgid(&init_user_ns, cred->egid), |
| from_kgid(&init_user_ns, cred->sgid), |
| from_kgid(&init_user_ns, cred->fsgid), |
| audit_get_sessionid(tsk), tty); |
| |
| get_task_comm(name, tsk); |
| audit_log_format(ab, " comm="); |
| audit_log_untrustedstring(ab, name); |
| |
| if (mm) { |
| down_read(&mm->mmap_sem); |
| if (mm->exe_file) |
| audit_log_d_path(ab, " exe=", &mm->exe_file->f_path); |
| up_read(&mm->mmap_sem); |
| } |
| audit_log_task_context(ab); |
| } |
| EXPORT_SYMBOL(audit_log_task_info); |
| |
| /** |
| * audit_log_link_denied - report a link restriction denial |
| * @operation: specific link opreation |
| * @link: the path that triggered the restriction |
| */ |
| void audit_log_link_denied(const char *operation, struct path *link) |
| { |
| struct audit_buffer *ab; |
| struct audit_names *name; |
| |
| name = kzalloc(sizeof(*name), GFP_NOFS); |
| if (!name) |
| return; |
| |
| /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
| ab = audit_log_start(current->audit_context, GFP_KERNEL, |
| AUDIT_ANOM_LINK); |
| if (!ab) |
| goto out; |
| audit_log_format(ab, "op=%s", operation); |
| audit_log_task_info(ab, current); |
| audit_log_format(ab, " res=0"); |
| audit_log_end(ab); |
| |
| /* Generate AUDIT_PATH record with object. */ |
| name->type = AUDIT_TYPE_NORMAL; |
| audit_copy_inode(name, link->dentry, link->dentry->d_inode); |
| audit_log_name(current->audit_context, name, link, 0, NULL); |
| out: |
| kfree(name); |
| } |
| |
| /** |
| * audit_log_end - end one audit record |
| * @ab: the audit_buffer |
| * |
| * The netlink_* functions cannot be called inside an irq context, so |
| * the audit buffer is placed on a queue and a tasklet is scheduled to |
| * remove them from the queue outside the irq context. May be called in |
| * any context. |
| */ |
| void audit_log_end(struct audit_buffer *ab) |
| { |
| if (!ab) |
| return; |
| if (!audit_rate_check()) { |
| audit_log_lost("rate limit exceeded"); |
| } else { |
| struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
| nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; |
| |
| if (audit_pid) { |
| skb_queue_tail(&audit_skb_queue, ab->skb); |
| wake_up_interruptible(&kauditd_wait); |
| } else { |
| audit_printk_skb(ab->skb); |
| } |
| ab->skb = NULL; |
| } |
| audit_buffer_free(ab); |
| } |
| |
| /** |
| * audit_log - Log an audit record |
| * @ctx: audit context |
| * @gfp_mask: type of allocation |
| * @type: audit message type |
| * @fmt: format string to use |
| * @...: variable parameters matching the format string |
| * |
| * This is a convenience function that calls audit_log_start, |
| * audit_log_vformat, and audit_log_end. It may be called |
| * in any context. |
| */ |
| void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
| const char *fmt, ...) |
| { |
| struct audit_buffer *ab; |
| va_list args; |
| |
| ab = audit_log_start(ctx, gfp_mask, type); |
| if (ab) { |
| va_start(args, fmt); |
| audit_log_vformat(ab, fmt, args); |
| va_end(args); |
| audit_log_end(ab); |
| } |
| } |
| |
| #ifdef CONFIG_SECURITY |
| /** |
| * audit_log_secctx - Converts and logs SELinux context |
| * @ab: audit_buffer |
| * @secid: security number |
| * |
| * This is a helper function that calls security_secid_to_secctx to convert |
| * secid to secctx and then adds the (converted) SELinux context to the audit |
| * log by calling audit_log_format, thus also preventing leak of internal secid |
| * to userspace. If secid cannot be converted audit_panic is called. |
| */ |
| void audit_log_secctx(struct audit_buffer *ab, u32 secid) |
| { |
| u32 len; |
| char *secctx; |
| |
| if (security_secid_to_secctx(secid, &secctx, &len)) { |
| audit_panic("Cannot convert secid to context"); |
| } else { |
| audit_log_format(ab, " obj=%s", secctx); |
| security_release_secctx(secctx, len); |
| } |
| } |
| EXPORT_SYMBOL(audit_log_secctx); |
| #endif |
| |
| EXPORT_SYMBOL(audit_log_start); |
| EXPORT_SYMBOL(audit_log_end); |
| EXPORT_SYMBOL(audit_log_format); |
| EXPORT_SYMBOL(audit_log); |