diff options
Diffstat (limited to 'kernel/audit.c')
| -rw-r--r-- | kernel/audit.c | 1256 |
1 files changed, 896 insertions, 360 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index 77770a034d5..3ef2e0e797e 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -41,23 +41,31 @@ * Example user-space utilities: http://people.redhat.com/sgrubb/audit/ */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/init.h> -#include <asm/types.h> -#include <asm/atomic.h> +#include <linux/types.h> +#include <linux/atomic.h> #include <linux/mm.h> -#include <linux/module.h> +#include <linux/export.h> #include <linux/slab.h> #include <linux/err.h> #include <linux/kthread.h> +#include <linux/kernel.h> +#include <linux/syscalls.h> #include <linux/audit.h> #include <net/sock.h> #include <net/netlink.h> #include <linux/skbuff.h> -#include <linux/netlink.h> +#ifdef CONFIG_SECURITY +#include <linux/security.h> +#endif #include <linux/freezer.h> #include <linux/tty.h> +#include <linux/pid_namespace.h> +#include <net/netns/generic.h> #include "audit.h" @@ -71,35 +79,39 @@ static int audit_initialized; #define AUDIT_OFF 0 #define AUDIT_ON 1 #define AUDIT_LOCKED 2 -int audit_enabled; -int audit_ever_enabled; +u32 audit_enabled; +u32 audit_ever_enabled; + +EXPORT_SYMBOL_GPL(audit_enabled); /* Default state when kernel boots without any parameters. */ -static int audit_default; +static u32 audit_default; /* If auditing cannot proceed, audit_failure selects what happens. */ -static int audit_failure = AUDIT_FAIL_PRINTK; +static u32 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_pid contains - * the pid to use to send netlink messages to that process. + * 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_pid; +static __u32 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; +static u32 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; +/* Number of outstanding audit_buffers allowed. + * When set to zero, this means unlimited. */ +static u32 audit_backlog_limit = 64; +#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ) +static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; +static u32 audit_backlog_wait_overflow = 0; /* The identity of the user shutting down the audit system. */ -uid_t audit_sig_uid = -1; +kuid_t audit_sig_uid = INVALID_UID; pid_t audit_sig_pid = -1; u32 audit_sig_sid = 0; @@ -114,6 +126,7 @@ static atomic_t audit_lost = ATOMIC_INIT(0); /* The netlink socket. */ static struct sock *audit_sock; +int audit_net_id; /* Hash for inode-based rules */ struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; @@ -132,6 +145,17 @@ static struct task_struct *kauditd_task; static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); +static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, + .mask = -1, + .features = 0, + .lock = 0,}; + +static char *audit_feature_names[2] = { + "only_unset_loginuid", + "loginuid_immutable", +}; + + /* Serialize requests from userspace. */ DEFINE_MUTEX(audit_cmd_mutex); @@ -157,27 +181,27 @@ struct audit_buffer { }; struct audit_reply { - int pid; + __u32 portid; + struct net *net; struct sk_buff *skb; }; -static void audit_set_pid(struct audit_buffer *ab, pid_t pid) +static void audit_set_portid(struct audit_buffer *ab, __u32 portid) { if (ab) { struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); - nlh->nlmsg_pid = pid; + nlh->nlmsg_pid = portid; } } void audit_panic(const char *message) { - switch (audit_failure) - { + switch (audit_failure) { case AUDIT_FAIL_SILENT: break; case AUDIT_FAIL_PRINTK: if (printk_ratelimit()) - printk(KERN_ERR "audit: %s\n", message); + pr_err("%s\n", message); break; case AUDIT_FAIL_PANIC: /* test audit_pid since printk is always losey, why bother? */ @@ -248,9 +272,7 @@ void audit_log_lost(const char *message) if (print) { if (printk_ratelimit()) - printk(KERN_WARNING - "audit: audit_lost=%d audit_rate_limit=%d " - "audit_backlog_limit=%d\n", + pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n", atomic_read(&audit_lost), audit_rate_limit, audit_backlog_limit); @@ -258,39 +280,29 @@ void audit_log_lost(const char *message) } } -static int audit_log_config_change(char *function_name, int new, int old, - uid_t loginuid, u32 sessionid, u32 sid, +static int audit_log_config_change(char *function_name, u32 new, u32 old, int allow_changes) { struct audit_buffer *ab; int rc = 0; ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); - audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new, - old, loginuid, sessionid); - if (sid) { - char *ctx = NULL; - u32 len; - - rc = security_secid_to_secctx(sid, &ctx, &len); - if (rc) { - audit_log_format(ab, " sid=%u", sid); - allow_changes = 0; /* Something weird, deny request */ - } else { - audit_log_format(ab, " subj=%s", ctx); - security_release_secctx(ctx, len); - } - } + if (unlikely(!ab)) + return rc; + audit_log_format(ab, "%s=%u old=%u", function_name, new, old); + audit_log_session_info(ab); + rc = audit_log_task_context(ab); + if (rc) + allow_changes = 0; /* Something weird, deny request */ audit_log_format(ab, " res=%d", allow_changes); audit_log_end(ab); return rc; } -static int audit_do_config_change(char *function_name, int *to_change, - int new, uid_t loginuid, u32 sessionid, - u32 sid) +static int audit_do_config_change(char *function_name, u32 *to_change, u32 new) { - int allow_changes, rc = 0, old = *to_change; + int allow_changes, rc = 0; + u32 old = *to_change; /* check if we are locked */ if (audit_enabled == AUDIT_LOCKED) @@ -299,8 +311,7 @@ static int audit_do_config_change(char *function_name, int *to_change, allow_changes = 1; if (audit_enabled != AUDIT_OFF) { - rc = audit_log_config_change(function_name, new, old, loginuid, - sessionid, sid, allow_changes); + rc = audit_log_config_change(function_name, new, old, allow_changes); if (rc) allow_changes = 0; } @@ -314,44 +325,43 @@ static int audit_do_config_change(char *function_name, int *to_change, return rc; } -static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid, - u32 sid) +static int audit_set_rate_limit(u32 limit) +{ + return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); +} + +static int audit_set_backlog_limit(u32 limit) { - return audit_do_config_change("audit_rate_limit", &audit_rate_limit, - limit, loginuid, sessionid, sid); + return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); } -static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid, - u32 sid) +static int audit_set_backlog_wait_time(u32 timeout) { - return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, - limit, loginuid, sessionid, sid); + return audit_do_config_change("audit_backlog_wait_time", + &audit_backlog_wait_time, timeout); } -static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid) +static int audit_set_enabled(u32 state) { int rc; if (state < AUDIT_OFF || state > AUDIT_LOCKED) return -EINVAL; - rc = audit_do_config_change("audit_enabled", &audit_enabled, state, - loginuid, sessionid, sid); - + 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, uid_t loginuid, u32 sessionid, u32 sid) +static int audit_set_failure(u32 state) { if (state != AUDIT_FAIL_SILENT && state != AUDIT_FAIL_PRINTK && state != AUDIT_FAIL_PANIC) return -EINVAL; - return audit_do_config_change("audit_failure", &audit_failure, state, - loginuid, sessionid, sid); + return audit_do_config_change("audit_failure", &audit_failure, state); } /* @@ -366,7 +376,8 @@ static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid) static void audit_hold_skb(struct sk_buff *skb) { if (audit_default && - skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) + (!audit_backlog_limit || + skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)) skb_queue_tail(&audit_skb_hold_queue, skb); else kfree_skb(skb); @@ -379,13 +390,13 @@ static void audit_hold_skb(struct sk_buff *skb) static void audit_printk_skb(struct sk_buff *skb) { struct nlmsghdr *nlh = nlmsg_hdr(skb); - char *data = NLMSG_DATA(nlh); + 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); + pr_notice("type=%d %s\n", nlh->nlmsg_type, data); else - audit_log_lost("printk limit exceeded\n"); + audit_log_lost("printk limit exceeded"); } audit_hold_skb(skb); @@ -396,12 +407,15 @@ static void kauditd_send_skb(struct sk_buff *skb) int err; /* take a reference in case we can't send it and we want to hold it */ skb_get(skb); - err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0); + 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 dissapeared\n"); - audit_pid = 0; + if (audit_pid) { + pr_err("*NO* daemon at audit_pid=%d\n", audit_pid); + audit_log_lost("auditd disappeared"); + audit_pid = 0; + audit_sock = NULL; + } /* we might get lucky and get this in the next auditd */ audit_hold_skb(skb); } else @@ -409,96 +423,132 @@ static void kauditd_send_skb(struct sk_buff *skb) consume_skb(skb); } -static int kauditd_thread(void *dummy) +/* + * kauditd_send_multicast_skb - send the skb to multicast userspace listeners + * + * This function doesn't consume an skb as might be expected since it has to + * copy it anyways. + */ +static void kauditd_send_multicast_skb(struct sk_buff *skb) +{ + struct sk_buff *copy; + struct audit_net *aunet = net_generic(&init_net, audit_net_id); + struct sock *sock = aunet->nlsk; + + if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG)) + return; + + /* + * The seemingly wasteful skb_copy() rather than bumping the refcount + * using skb_get() is necessary because non-standard mods are made to + * the skb by the original kaudit unicast socket send routine. The + * existing auditd daemon assumes this breakage. Fixing this would + * require co-ordinating a change in the established protocol between + * the kaudit kernel subsystem and the auditd userspace code. There is + * no reason for new multicast clients to continue with this + * non-compliance. + */ + copy = skb_copy(skb, GFP_KERNEL); + if (!copy) + return; + + nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL); +} + +/* + * 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()) { - /* - * if auditd just started drain the queue of messages already - * sent to syslog/printk. remember loss here is ok. we already - * called audit_log_lost() if it didn't go out normally. so the - * race between the skb_dequeue and the next check for audit_pid - * doesn't matter. - * - * if you ever find kauditd to be too slow we can get a perf win - * by doing our own locking and keeping better track if there - * are messages in this queue. I don't see the need now, but - * in 5 years when I want to play with this again I'll see this - * note and still have no friggin idea what i'm thinking today. - */ - if (audit_default && audit_pid) { - skb = skb_dequeue(&audit_skb_hold_queue); - if (unlikely(skb)) { - while (skb && audit_pid) { - kauditd_send_skb(skb); - skb = skb_dequeue(&audit_skb_hold_queue); - } - } - } + 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 (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit) + wake_up(&audit_backlog_wait); if (audit_pid) kauditd_send_skb(skb); else audit_printk_skb(skb); - } else { - DECLARE_WAITQUEUE(wait, current); - 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); + continue; } - } - return 0; -} + set_current_state(TASK_INTERRUPTIBLE); + add_wait_queue(&kauditd_wait, &wait); -static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid) -{ - struct task_struct *tsk; - int err; + if (!skb_queue_len(&audit_skb_queue)) { + try_to_freeze(); + schedule(); + } - rcu_read_lock(); - tsk = find_task_by_vpid(pid); - if (!tsk) { - rcu_read_unlock(); - return -ESRCH; + __set_current_state(TASK_RUNNING); + remove_wait_queue(&kauditd_wait, &wait); } - get_task_struct(tsk); - rcu_read_unlock(); - err = tty_audit_push_task(tsk, loginuid, sessionid); - put_task_struct(tsk); - return err; + return 0; } int audit_send_list(void *_dest) { struct audit_netlink_list *dest = _dest; - int pid = dest->pid; struct sk_buff *skb; + struct net *net = dest->net; + struct audit_net *aunet = net_generic(net, audit_net_id); /* 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); + netlink_unicast(aunet->nlsk, skb, dest->portid, 0); + put_net(net); kfree(dest); return 0; } -struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, +struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done, int multi, const void *payload, int size) { struct sk_buff *skb; @@ -511,33 +561,37 @@ struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, if (!skb) return NULL; - nlh = NLMSG_NEW(skb, pid, seq, t, size, flags); - data = NLMSG_DATA(nlh); + nlh = nlmsg_put(skb, portid, seq, t, size, flags); + if (!nlh) + goto out_kfree_skb; + data = nlmsg_data(nlh); memcpy(data, payload, size); return skb; -nlmsg_failure: /* Used by NLMSG_NEW */ - if (skb) - kfree_skb(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; + struct net *net = reply->net; + struct audit_net *aunet = net_generic(net, audit_net_id); 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); + netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0); + put_net(net); kfree(reply); return 0; } /** * audit_send_reply - send an audit reply message via netlink - * @pid: process id to send reply to + * @request_skb: skb of request we are replying to (used to target the reply) * @seq: sequence number * @type: audit message type * @done: done (last) flag @@ -545,12 +599,14 @@ static int audit_send_reply_thread(void *arg) * @payload: payload data * @size: payload size * - * Allocates an skb, builds the netlink message, and sends it to the pid. + * Allocates an skb, builds the netlink message, and sends it to the port id. * No failure notifications. */ -static void audit_send_reply(int pid, int seq, int type, int done, int multi, - const void *payload, int size) +static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done, + int multi, const void *payload, int size) { + u32 portid = NETLINK_CB(request_skb).portid; + struct net *net = sock_net(NETLINK_CB(request_skb).sk); struct sk_buff *skb; struct task_struct *tsk; struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), @@ -559,11 +615,12 @@ static void audit_send_reply(int pid, int seq, int type, int done, int multi, if (!reply) return; - skb = audit_make_reply(pid, seq, type, done, multi, payload, size); + skb = audit_make_reply(portid, seq, type, done, multi, payload, size); if (!skb) goto out; - reply->pid = pid; + reply->net = get_net(net); + reply->portid = portid; reply->skb = skb; tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); @@ -582,27 +639,49 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) { int err = 0; + /* Only support initial user namespace for now. */ + /* + * We return ECONNREFUSED because it tricks userspace into thinking + * that audit was not configured into the kernel. Lots of users + * configure their PAM stack (because that's what the distro does) + * to reject login if unable to send messages to audit. If we return + * ECONNREFUSED the PAM stack thinks the kernel does not have audit + * configured in and will let login proceed. If we return EPERM + * userspace will reject all logins. This should be removed when we + * support non init namespaces!! + */ + if (current_user_ns() != &init_user_ns) + return -ECONNREFUSED; + switch (msg_type) { - case AUDIT_GET: case AUDIT_LIST: - case AUDIT_LIST_RULES: - case AUDIT_SET: case AUDIT_ADD: - case AUDIT_ADD_RULE: case AUDIT_DEL: + return -EOPNOTSUPP; + case AUDIT_GET: + case AUDIT_SET: + case AUDIT_GET_FEATURE: + case AUDIT_SET_FEATURE: + case AUDIT_LIST_RULES: + case AUDIT_ADD_RULE: case AUDIT_DEL_RULE: case AUDIT_SIGNAL_INFO: case AUDIT_TTY_GET: case AUDIT_TTY_SET: case AUDIT_TRIM: case AUDIT_MAKE_EQUIV: - if (security_netlink_recv(skb, CAP_AUDIT_CONTROL)) + /* Only support auditd and auditctl in initial pid namespace + * for now. */ + if ((task_active_pid_ns(current) != &init_pid_ns)) + return -EPERM; + + if (!netlink_capable(skb, CAP_AUDIT_CONTROL)) err = -EPERM; break; case AUDIT_USER: case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: - if (security_netlink_recv(skb, CAP_AUDIT_WRITE)) + if (!netlink_capable(skb, CAP_AUDIT_WRITE)) err = -EPERM; break; default: /* bad msg */ @@ -612,45 +691,125 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) return err; } -static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type, - u32 pid, u32 uid, uid_t auid, u32 ses, - u32 sid) +static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) { int rc = 0; - char *ctx = NULL; - u32 len; + uid_t uid = from_kuid(&init_user_ns, current_uid()); + pid_t pid = task_tgid_nr(current); - if (!audit_enabled) { + if (!audit_enabled && msg_type != AUDIT_USER_AVC) { *ab = NULL; return rc; } *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); - audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u", - pid, uid, auid, ses); - if (sid) { - rc = security_secid_to_secctx(sid, &ctx, &len); - if (rc) - audit_log_format(*ab, " ssid=%u", sid); - else { - audit_log_format(*ab, " subj=%s", ctx); - security_release_secctx(ctx, len); + if (unlikely(!*ab)) + return rc; + audit_log_format(*ab, "pid=%d uid=%u", pid, uid); + audit_log_session_info(*ab); + audit_log_task_context(*ab); + + return rc; +} + +int is_audit_feature_set(int i) +{ + return af.features & AUDIT_FEATURE_TO_MASK(i); +} + + +static int audit_get_feature(struct sk_buff *skb) +{ + u32 seq; + + seq = nlmsg_hdr(skb)->nlmsg_seq; + + audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &af, sizeof(af)); + + return 0; +} + +static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, + u32 old_lock, u32 new_lock, int res) +{ + struct audit_buffer *ab; + + if (audit_enabled == AUDIT_OFF) + return; + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); + audit_log_task_info(ab, current); + audit_log_format(ab, "feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d", + audit_feature_names[which], !!old_feature, !!new_feature, + !!old_lock, !!new_lock, res); + audit_log_end(ab); +} + +static int audit_set_feature(struct sk_buff *skb) +{ + struct audit_features *uaf; + int i; + + BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > sizeof(audit_feature_names)/sizeof(audit_feature_names[0])); + uaf = nlmsg_data(nlmsg_hdr(skb)); + + /* if there is ever a version 2 we should handle that here */ + + for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { + u32 feature = AUDIT_FEATURE_TO_MASK(i); + u32 old_feature, new_feature, old_lock, new_lock; + + /* if we are not changing this feature, move along */ + if (!(feature & uaf->mask)) + continue; + + old_feature = af.features & feature; + new_feature = uaf->features & feature; + new_lock = (uaf->lock | af.lock) & feature; + old_lock = af.lock & feature; + + /* are we changing a locked feature? */ + if (old_lock && (new_feature != old_feature)) { + audit_log_feature_change(i, old_feature, new_feature, + old_lock, new_lock, 0); + return -EPERM; } } + /* nothing invalid, do the changes */ + for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { + u32 feature = AUDIT_FEATURE_TO_MASK(i); + u32 old_feature, new_feature, old_lock, new_lock; - return rc; + /* if we are not changing this feature, move along */ + if (!(feature & uaf->mask)) + continue; + + old_feature = af.features & feature; + new_feature = uaf->features & feature; + old_lock = af.lock & feature; + new_lock = (uaf->lock | af.lock) & feature; + + if (new_feature != old_feature) + audit_log_feature_change(i, old_feature, new_feature, + old_lock, new_lock, 1); + + if (new_feature) + af.features |= feature; + else + af.features &= ~feature; + af.lock |= new_lock; + } + + return 0; } static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) { - u32 uid, pid, seq, sid; + u32 seq; void *data; - struct audit_status *status_get, status_set; int err; struct audit_buffer *ab; u16 msg_type = nlh->nlmsg_type; - uid_t loginuid; /* loginuid of sender */ - u32 sessionid; struct audit_sig_info *sig_data; char *ctx = NULL; u32 len; @@ -661,70 +820,90 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) /* As soon as there's any sign of userspace auditd, * start kauditd to talk to it */ - if (!kauditd_task) + 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; + if (IS_ERR(kauditd_task)) { + err = PTR_ERR(kauditd_task); + kauditd_task = NULL; + return err; + } } - - pid = NETLINK_CREDS(skb)->pid; - uid = NETLINK_CREDS(skb)->uid; - loginuid = NETLINK_CB(skb).loginuid; - sessionid = NETLINK_CB(skb).sessionid; - sid = NETLINK_CB(skb).sid; seq = nlh->nlmsg_seq; - data = NLMSG_DATA(nlh); + 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).pid, seq, AUDIT_GET, 0, 0, - &status_set, sizeof(status_set)); + case AUDIT_GET: { + struct audit_status s; + memset(&s, 0, sizeof(s)); + s.enabled = audit_enabled; + s.failure = audit_failure; + s.pid = audit_pid; + s.rate_limit = audit_rate_limit; + s.backlog_limit = audit_backlog_limit; + s.lost = atomic_read(&audit_lost); + s.backlog = skb_queue_len(&audit_skb_queue); + s.version = AUDIT_VERSION_LATEST; + s.backlog_wait_time = audit_backlog_wait_time; + audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s)); 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, - loginuid, sessionid, sid); + } + case AUDIT_SET: { + struct audit_status s; + memset(&s, 0, sizeof(s)); + /* guard against past and future API changes */ + memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); + if (s.mask & AUDIT_STATUS_ENABLED) { + err = audit_set_enabled(s.enabled); if (err < 0) return err; } - if (status_get->mask & AUDIT_STATUS_FAILURE) { - err = audit_set_failure(status_get->failure, - loginuid, sessionid, sid); + if (s.mask & AUDIT_STATUS_FAILURE) { + err = audit_set_failure(s.failure); if (err < 0) return err; } - if (status_get->mask & AUDIT_STATUS_PID) { - int new_pid = status_get->pid; + if (s.mask & AUDIT_STATUS_PID) { + int new_pid = s.pid; + if ((!new_pid) && (task_tgid_vnr(current) != audit_pid)) + return -EACCES; if (audit_enabled != AUDIT_OFF) - audit_log_config_change("audit_pid", new_pid, - audit_pid, loginuid, - sessionid, sid, 1); - + audit_log_config_change("audit_pid", new_pid, audit_pid, 1); audit_pid = new_pid; - audit_nlk_pid = NETLINK_CB(skb).pid; + audit_nlk_portid = NETLINK_CB(skb).portid; + audit_sock = skb->sk; + } + if (s.mask & AUDIT_STATUS_RATE_LIMIT) { + err = audit_set_rate_limit(s.rate_limit); + if (err < 0) + return err; + } + if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) { + err = audit_set_backlog_limit(s.backlog_limit); + if (err < 0) + return err; } - if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { - err = audit_set_rate_limit(status_get->rate_limit, - loginuid, sessionid, sid); + if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) { + if (sizeof(s) > (size_t)nlh->nlmsg_len) + return -EINVAL; + if (s.backlog_wait_time < 0 || + s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME) + return -EINVAL; + err = audit_set_backlog_wait_time(s.backlog_wait_time); if (err < 0) return err; } - if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) - err = audit_set_backlog_limit(status_get->backlog_limit, - loginuid, sessionid, sid); + break; + } + case AUDIT_GET_FEATURE: + err = audit_get_feature(skb); + if (err) + return err; + break; + case AUDIT_SET_FEATURE: + err = audit_set_feature(skb); + if (err) + return err; break; case AUDIT_USER: case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: @@ -732,79 +911,54 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (!audit_enabled && msg_type != AUDIT_USER_AVC) return 0; - err = audit_filter_user(&NETLINK_CB(skb)); - if (err == 1) { + err = audit_filter_user(msg_type); + if (err == 1) { /* match or error */ err = 0; if (msg_type == AUDIT_USER_TTY) { - err = audit_prepare_user_tty(pid, loginuid, - sessionid); + err = tty_audit_push_current(); if (err) break; } - audit_log_common_recv_msg(&ab, msg_type, pid, uid, - loginuid, sessionid, sid); - + mutex_unlock(&audit_cmd_mutex); + audit_log_common_recv_msg(&ab, msg_type); if (msg_type != AUDIT_USER_TTY) - audit_log_format(ab, " msg='%.1024s'", + audit_log_format(ab, " msg='%.*s'", + AUDIT_MESSAGE_TEXT_MAX, (char *)data); else { int size; - audit_log_format(ab, " msg="); + 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, pid); + audit_set_portid(ab, NETLINK_CB(skb).portid); audit_log_end(ab); + mutex_lock(&audit_cmd_mutex); } break; - case AUDIT_ADD: - case AUDIT_DEL: - if (nlmsg_len(nlh) < sizeof(struct audit_rule)) - return -EINVAL; - if (audit_enabled == AUDIT_LOCKED) { - audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, - uid, loginuid, sessionid, sid); - - audit_log_format(ab, " audit_enabled=%d res=0", - audit_enabled); - audit_log_end(ab); - return -EPERM; - } - /* fallthrough */ - case AUDIT_LIST: - err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid, - uid, seq, data, nlmsg_len(nlh), - loginuid, sessionid, sid); - break; case AUDIT_ADD_RULE: case AUDIT_DEL_RULE: if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) return -EINVAL; if (audit_enabled == AUDIT_LOCKED) { - audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, - uid, loginuid, sessionid, sid); - - audit_log_format(ab, " audit_enabled=%d res=0", - audit_enabled); + audit_log_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 */ + err = audit_rule_change(msg_type, NETLINK_CB(skb).portid, + seq, data, nlmsg_len(nlh)); + break; case AUDIT_LIST_RULES: - err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid, - uid, seq, data, nlmsg_len(nlh), - loginuid, sessionid, sid); + err = audit_list_rules_send(skb, seq); break; case AUDIT_TRIM: audit_trim_trees(); - - audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, - uid, loginuid, sessionid, sid); - + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); audit_log_format(ab, " op=trim res=1"); audit_log_end(ab); break; @@ -834,8 +988,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) /* OK, here comes... */ err = audit_tag_tree(old, new); - audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, - uid, loginuid, sessionid, sid); + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); audit_log_format(ab, " op=make_equiv old="); audit_log_untrustedstring(ab, old); @@ -860,53 +1013,56 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) security_release_secctx(ctx, len); return -ENOMEM; } - sig_data->uid = audit_sig_uid; + 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).pid, seq, AUDIT_SIGNAL_INFO, - 0, 0, sig_data, sizeof(*sig_data) + len); + audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, + sig_data, sizeof(*sig_data) + len); kfree(sig_data); break; case AUDIT_TTY_GET: { struct audit_tty_status s; - struct task_struct *tsk; - unsigned long flags; - - rcu_read_lock(); - tsk = find_task_by_vpid(pid); - if (tsk && lock_task_sighand(tsk, &flags)) { - s.enabled = tsk->signal->audit_tty != 0; - unlock_task_sighand(tsk, &flags); - } else - err = -ESRCH; - rcu_read_unlock(); - - if (!err) - audit_send_reply(NETLINK_CB(skb).pid, seq, - AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); + struct task_struct *tsk = current; + + spin_lock(&tsk->sighand->siglock); + s.enabled = tsk->signal->audit_tty; + s.log_passwd = tsk->signal->audit_tty_log_passwd; + spin_unlock(&tsk->sighand->siglock); + + audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); break; } case AUDIT_TTY_SET: { - struct audit_tty_status *s; - struct task_struct *tsk; - unsigned long flags; + struct audit_tty_status s, old; + struct task_struct *tsk = current; + struct audit_buffer *ab; + + memset(&s, 0, sizeof(s)); + /* guard against past and future API changes */ + memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); + /* check if new data is valid */ + if ((s.enabled != 0 && s.enabled != 1) || + (s.log_passwd != 0 && s.log_passwd != 1)) + err = -EINVAL; + + spin_lock(&tsk->sighand->siglock); + old.enabled = tsk->signal->audit_tty; + old.log_passwd = tsk->signal->audit_tty_log_passwd; + if (!err) { + tsk->signal->audit_tty = s.enabled; + tsk->signal->audit_tty_log_passwd = s.log_passwd; + } + spin_unlock(&tsk->sighand->siglock); - if (nlh->nlmsg_len < sizeof(struct audit_tty_status)) - return -EINVAL; - s = data; - if (s->enabled != 0 && s->enabled != 1) - return -EINVAL; - rcu_read_lock(); - tsk = find_task_by_vpid(pid); - if (tsk && lock_task_sighand(tsk, &flags)) { - tsk->signal->audit_tty = s->enabled != 0; - unlock_task_sighand(tsk, &flags); - } else - err = -ESRCH; - rcu_read_unlock(); + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); + audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d" + " old-log_passwd=%d new-log_passwd=%d res=%d", + old.enabled, s.enabled, old.log_passwd, + s.log_passwd, !err); + audit_log_end(ab); break; } default: @@ -925,7 +1081,7 @@ 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 + * len MUST be signed for nlmsg_next to be able to dec it below 0 * if the nlmsg_len was not aligned */ int len; @@ -934,13 +1090,13 @@ static void audit_receive_skb(struct sk_buff *skb) nlh = nlmsg_hdr(skb); len = skb->len; - while (NLMSG_OK(nlh, 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); + nlh = nlmsg_next(nlh, &len); } } @@ -952,6 +1108,56 @@ static void audit_receive(struct sk_buff *skb) mutex_unlock(&audit_cmd_mutex); } +/* Run custom bind function on netlink socket group connect or bind requests. */ +static int audit_bind(int group) +{ + if (!capable(CAP_AUDIT_READ)) + return -EPERM; + + return 0; +} + +static int __net_init audit_net_init(struct net *net) +{ + struct netlink_kernel_cfg cfg = { + .input = audit_receive, + .bind = audit_bind, + .flags = NL_CFG_F_NONROOT_RECV, + .groups = AUDIT_NLGRP_MAX, + }; + + struct audit_net *aunet = net_generic(net, audit_net_id); + + aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); + if (aunet->nlsk == NULL) { + audit_panic("cannot initialize netlink socket in namespace"); + return -ENOMEM; + } + aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; + return 0; +} + +static void __net_exit audit_net_exit(struct net *net) +{ + struct audit_net *aunet = net_generic(net, audit_net_id); + struct sock *sock = aunet->nlsk; + if (sock == audit_sock) { + audit_pid = 0; + audit_sock = NULL; + } + + RCU_INIT_POINTER(aunet->nlsk, NULL); + synchronize_net(); + netlink_kernel_release(sock); +} + +static struct pernet_operations audit_net_ops __net_initdata = { + .init = audit_net_init, + .exit = audit_net_exit, + .id = &audit_net_id, + .size = sizeof(struct audit_net), +}; + /* Initialize audit support at boot time. */ static int __init audit_init(void) { @@ -960,14 +1166,9 @@ static int __init audit_init(void) 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, 0, - audit_receive, NULL, THIS_MODULE); - if (!audit_sock) - audit_panic("cannot initialize netlink socket"); - else - audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; + pr_info("initializing netlink subsys (%s)\n", + audit_default ? "enabled" : "disabled"); + register_pernet_subsys(&audit_net_ops); skb_queue_head_init(&audit_skb_queue); skb_queue_head_init(&audit_skb_hold_queue); @@ -991,22 +1192,32 @@ static int __init audit_enable(char *str) if (!audit_default) audit_initialized = AUDIT_DISABLED; - printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled"); + pr_info("%s\n", audit_default ? + "enabled (after initialization)" : "disabled (until reboot)"); - 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)"); + return 1; +} +__setup("audit=", audit_enable); + +/* Process kernel command-line parameter at boot time. + * audit_backlog_limit=<n> */ +static int __init audit_backlog_limit_set(char *str) +{ + u32 audit_backlog_limit_arg; + + pr_info("audit_backlog_limit: "); + if (kstrtouint(str, 0, &audit_backlog_limit_arg)) { + pr_cont("using default of %u, unable to parse %s\n", + audit_backlog_limit, str); + return 1; } - printk("\n"); + + audit_backlog_limit = audit_backlog_limit_arg; + pr_cont("%d\n", audit_backlog_limit); return 1; } - -__setup("audit=", audit_enable); +__setup("audit_backlog_limit=", audit_backlog_limit_set); static void audit_buffer_free(struct audit_buffer *ab) { @@ -1055,13 +1266,15 @@ static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); if (!ab->skb) - goto nlmsg_failure; + goto err; - nlh = NLMSG_NEW(ab->skb, 0, 0, type, 0, 0); + nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); + if (!nlh) + goto out_kfree_skb; return ab; -nlmsg_failure: /* Used by NLMSG_NEW */ +out_kfree_skb: kfree_skb(ab->skb); ab->skb = NULL; err: @@ -1112,12 +1325,24 @@ static inline void audit_get_stamp(struct audit_context *ctx, } } -/* 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. */ +/* + * Wait for auditd to drain the queue a little + */ +static long wait_for_auditd(long sleep_time) +{ + DECLARE_WAITQUEUE(wait, current); + set_current_state(TASK_UNINTERRUPTIBLE); + add_wait_queue_exclusive(&audit_backlog_wait, &wait); + + if (audit_backlog_limit && + skb_queue_len(&audit_skb_queue) > audit_backlog_limit) + sleep_time = schedule_timeout(sleep_time); + + __set_current_state(TASK_RUNNING); + remove_wait_queue(&audit_backlog_wait, &wait); + + return sleep_time; +} /** * audit_log_start - obtain an audit buffer @@ -1140,7 +1365,8 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, struct audit_buffer *ab = NULL; struct timespec t; unsigned int uninitialized_var(serial); - int reserve; + int reserve = 5; /* Allow atomic callers to go up to five + entries over the normal backlog limit */ unsigned long timeout_start = jiffies; if (audit_initialized != AUDIT_INITIALIZED) @@ -1149,42 +1375,37 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, 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 */ + if (gfp_mask & __GFP_WAIT) { + if (audit_pid && audit_pid == current->pid) + gfp_mask &= ~__GFP_WAIT; + else + reserve = 0; + } while (audit_backlog_limit && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { - if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time - && time_before(jiffies, timeout_start + audit_backlog_wait_time)) { - - /* Wait for auditd to drain the queue a little */ - DECLARE_WAITQUEUE(wait, current); - set_current_state(TASK_INTERRUPTIBLE); - add_wait_queue(&audit_backlog_wait, &wait); - - if (audit_backlog_limit && - skb_queue_len(&audit_skb_queue) > audit_backlog_limit) - schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies); - - __set_current_state(TASK_RUNNING); - remove_wait_queue(&audit_backlog_wait, &wait); - continue; + if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { + long sleep_time; + + sleep_time = timeout_start + audit_backlog_wait_time - jiffies; + if (sleep_time > 0) { + sleep_time = wait_for_auditd(sleep_time); + if (sleep_time > 0) + 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); + pr_warn("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; } + audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; + ab = audit_buffer_alloc(ctx, gfp_mask, type); if (!ab) { audit_log_lost("out of memory in audit_log_start"); @@ -1255,12 +1476,13 @@ static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, avail = audit_expand(ab, max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); if (!avail) - goto out; + goto out_va_end; len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); } - va_end(args2); if (len > 0) skb_put(skb, len); +out_va_end: + va_end(args2); out: return; } @@ -1301,7 +1523,6 @@ void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, int i, avail, new_len; unsigned char *ptr; struct sk_buff *skb; - static const unsigned char *hex = "0123456789ABCDEF"; if (!ab) return; @@ -1319,10 +1540,8 @@ void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, } 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 */ - } + for (i = 0; i < len; i++) + ptr = hex_byte_pack_upper(ptr, buf[i]); *ptr = 0; skb_put(skb, len << 1); /* new string is twice the old string */ } @@ -1412,12 +1631,12 @@ void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) /* This is a helper-function to print the escaped d_path */ void audit_log_d_path(struct audit_buffer *ab, const char *prefix, - struct path *path) + const struct path *path) { char *p, *pathname; if (prefix) - audit_log_format(ab, " %s", prefix); + audit_log_format(ab, "%s", prefix); /* We will allow 11 spaces for ' (deleted)' to be appended */ pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); @@ -1434,6 +1653,14 @@ void audit_log_d_path(struct audit_buffer *ab, const char *prefix, kfree(pathname); } +void audit_log_session_info(struct audit_buffer *ab) +{ + unsigned int sessionid = audit_get_sessionid(current); + uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); + + audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); +} + void audit_log_key(struct audit_buffer *ab, char *key) { audit_log_format(ab, " key="); @@ -1443,14 +1670,285 @@ void audit_log_key(struct audit_buffer *ab, char *key) 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); + } + } + + /* log the audit_names record type */ + audit_log_format(ab, " nametype="); + switch(n->type) { + case AUDIT_TYPE_NORMAL: + audit_log_format(ab, "NORMAL"); + break; + case AUDIT_TYPE_PARENT: + audit_log_format(ab, "PARENT"); + break; + case AUDIT_TYPE_CHILD_DELETE: + audit_log_format(ab, "DELETE"); + break; + case AUDIT_TYPE_CHILD_CREATE: + audit_log_format(ab, "CREATE"); + break; + default: + audit_log_format(ab, "UNKNOWN"); + break; + } + + 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=%d pid=%d auid=%u uid=%u gid=%u" + " euid=%u suid=%u fsuid=%u" + " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", + task_ppid_nr(tsk), + task_pid_nr(tsk), + 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), + tty, audit_get_sessionid(tsk)); + + 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); + } else + audit_log_format(ab, " exe=(null)"); + 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. + * netlink_unicast() cannot be called inside an irq context because it blocks + * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed + * on a queue and a 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) { @@ -1460,7 +1958,19 @@ void audit_log_end(struct audit_buffer *ab) audit_log_lost("rate limit exceeded"); } else { struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); - nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); + + kauditd_send_multicast_skb(ab->skb); + + /* + * The original kaudit unicast socket sends up messages with + * nlmsg_len set to the payload length rather than the entire + * message length. This breaks the standard set by netlink. + * The existing auditd daemon assumes this breakage. Fixing + * this would require co-ordinating a change in the established + * protocol between the kaudit kernel subsystem and the auditd + * userspace code. + */ + nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; if (audit_pid) { skb_queue_tail(&audit_skb_queue, ab->skb); @@ -1500,6 +2010,32 @@ void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, } } +#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); |