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Diffstat (limited to 'kernel/audit.c')
-rw-r--r--kernel/audit.c128
1 files changed, 79 insertions, 49 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index 7f0699790d4..83096b67510 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -79,6 +79,8 @@ 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. */
uid_t audit_sig_uid = -1;
@@ -106,18 +108,12 @@ static LIST_HEAD(audit_freelist);
static struct sk_buff_head audit_skb_queue;
static struct task_struct *kauditd_task;
static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
-
-/* There are three lists of rules -- one to search at task creation
- * time, one to search at syscall entry time, and another to search at
- * syscall exit time. */
-static LIST_HEAD(audit_tsklist);
-static LIST_HEAD(audit_entlist);
-static LIST_HEAD(audit_extlist);
+static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
/* The netlink socket is only to be read by 1 CPU, which lets us assume
* that list additions and deletions never happen simultaneously in
* auditsc.c */
-static DECLARE_MUTEX(audit_netlink_sem);
+DECLARE_MUTEX(audit_netlink_sem);
/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
* audit records. Since printk uses a 1024 byte buffer, this buffer
@@ -137,6 +133,7 @@ struct audit_buffer {
struct list_head list;
struct sk_buff *skb; /* formatted skb ready to send */
struct audit_context *ctx; /* NULL or associated context */
+ int gfp_mask;
};
static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
@@ -145,11 +142,6 @@ static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
nlh->nlmsg_pid = pid;
}
-struct audit_entry {
- struct list_head list;
- struct audit_rule rule;
-};
-
static void audit_panic(const char *message)
{
switch (audit_failure)
@@ -233,7 +225,7 @@ static int audit_set_rate_limit(int limit, uid_t loginuid)
{
int old = audit_rate_limit;
audit_rate_limit = limit;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
"audit_rate_limit=%d old=%d by auid=%u",
audit_rate_limit, old, loginuid);
return old;
@@ -243,7 +235,7 @@ static int audit_set_backlog_limit(int limit, uid_t loginuid)
{
int old = audit_backlog_limit;
audit_backlog_limit = limit;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
"audit_backlog_limit=%d old=%d by auid=%u",
audit_backlog_limit, old, loginuid);
return old;
@@ -255,7 +247,7 @@ static int audit_set_enabled(int state, uid_t loginuid)
if (state != 0 && state != 1)
return -EINVAL;
audit_enabled = state;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
"audit_enabled=%d old=%d by auid=%u",
audit_enabled, old, loginuid);
return old;
@@ -269,7 +261,7 @@ static int audit_set_failure(int state, uid_t loginuid)
&& state != AUDIT_FAIL_PANIC)
return -EINVAL;
audit_failure = state;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
"audit_failure=%d old=%d by auid=%u",
audit_failure, old, loginuid);
return old;
@@ -281,6 +273,7 @@ int kauditd_thread(void *dummy)
while (1) {
skb = skb_dequeue(&audit_skb_queue);
+ wake_up(&audit_backlog_wait);
if (skb) {
if (audit_pid) {
int err = netlink_unicast(audit_sock, skb, audit_pid, 0);
@@ -290,7 +283,7 @@ int kauditd_thread(void *dummy)
audit_pid = 0;
}
} else {
- printk(KERN_ERR "%s\n", skb->data + NLMSG_SPACE(0));
+ printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0));
kfree_skb(skb);
}
} else {
@@ -423,7 +416,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (status_get->mask & AUDIT_STATUS_PID) {
int old = audit_pid;
audit_pid = status_get->pid;
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
"audit_pid=%d old=%d by auid=%u",
audit_pid, old, loginuid);
}
@@ -435,15 +428,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
break;
case AUDIT_USER:
case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
- ab = audit_log_start(NULL, msg_type);
- if (!ab)
- break; /* audit_panic has been called */
- audit_log_format(ab,
- "user pid=%d uid=%u auid=%u"
- " msg='%.1024s'",
- pid, uid, loginuid, (char *)data);
- audit_set_pid(ab, pid);
- audit_log_end(ab);
+ if (!audit_enabled && msg_type != AUDIT_USER_AVC)
+ return 0;
+
+ err = audit_filter_user(&NETLINK_CB(skb), msg_type);
+ if (err == 1) {
+ err = 0;
+ ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
+ if (ab) {
+ audit_log_format(ab,
+ "user pid=%d uid=%u auid=%u msg='%.1024s'",
+ pid, uid, loginuid, (char *)data);
+ audit_set_pid(ab, pid);
+ audit_log_end(ab);
+ }
+ }
break;
case AUDIT_ADD:
case AUDIT_DEL:
@@ -523,7 +522,7 @@ static int __init audit_init(void)
skb_queue_head_init(&audit_skb_queue);
audit_initialized = 1;
audit_enabled = audit_default;
- audit_log(NULL, AUDIT_KERNEL, "initialized");
+ audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
return 0;
}
__initcall(audit_init);
@@ -561,7 +560,7 @@ static void audit_buffer_free(struct audit_buffer *ab)
}
static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
- int gfp_mask, int type)
+ unsigned int __nocast gfp_mask, int type)
{
unsigned long flags;
struct audit_buffer *ab = NULL;
@@ -587,6 +586,7 @@ static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
goto err;
ab->ctx = ctx;
+ ab->gfp_mask = gfp_mask;
nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0));
nlh->nlmsg_type = type;
nlh->nlmsg_flags = 0;
@@ -606,26 +606,27 @@ err:
* (timestamp,serial) tuple is unique for each syscall and is live from
* syscall entry to syscall exit.
*
- * Atomic values are only guaranteed to be 24-bit, so we count down.
- *
* NOTE: Another possibility is to store the formatted records off the
* audit context (for those records that have a context), and emit them
* all at syscall exit. However, this could delay the reporting of
* significant errors until syscall exit (or never, if the system
* halts). */
+
unsigned int audit_serial(void)
{
- static atomic_t serial = ATOMIC_INIT(0xffffff);
- unsigned int a, b;
+ static spinlock_t serial_lock = SPIN_LOCK_UNLOCKED;
+ static unsigned int serial = 0;
+
+ unsigned long flags;
+ unsigned int ret;
+ spin_lock_irqsave(&serial_lock, flags);
do {
- a = atomic_read(&serial);
- if (atomic_dec_and_test(&serial))
- atomic_set(&serial, 0xffffff);
- b = atomic_read(&serial);
- } while (b != a - 1);
+ ret = ++serial;
+ } while (unlikely(!ret));
+ spin_unlock_irqrestore(&serial_lock, flags);
- return 0xffffff - b;
+ return ret;
}
static inline void audit_get_stamp(struct audit_context *ctx,
@@ -645,17 +646,43 @@ static inline void audit_get_stamp(struct audit_context *ctx,
* 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. */
-struct audit_buffer *audit_log_start(struct audit_context *ctx, int type)
+
+struct audit_buffer *audit_log_start(struct audit_context *ctx, int gfp_mask,
+ int type)
{
struct audit_buffer *ab = NULL;
struct timespec t;
unsigned int serial;
+ int reserve;
+ unsigned long timeout_start = jiffies;
if (!audit_initialized)
return NULL;
- if (audit_backlog_limit
- && skb_queue_len(&audit_skb_queue) > audit_backlog_limit) {
+ 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
+ && 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 (audit_rate_check())
printk(KERN_WARNING
"audit: audit_backlog=%d > "
@@ -663,10 +690,12 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, int type)
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_ATOMIC, type);
+ ab = audit_buffer_alloc(ctx, gfp_mask, type);
if (!ab) {
audit_log_lost("out of memory in audit_log_start");
return NULL;
@@ -690,7 +719,7 @@ static inline int audit_expand(struct audit_buffer *ab, int extra)
{
struct sk_buff *skb = ab->skb;
int ret = pskb_expand_head(skb, skb_headroom(skb), extra,
- GFP_ATOMIC);
+ ab->gfp_mask);
if (ret < 0) {
audit_log_lost("out of memory in audit_expand");
return 0;
@@ -809,7 +838,7 @@ void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
audit_log_format(ab, " %s", prefix);
/* We will allow 11 spaces for ' (deleted)' to be appended */
- path = kmalloc(PATH_MAX+11, GFP_KERNEL);
+ path = kmalloc(PATH_MAX+11, ab->gfp_mask);
if (!path) {
audit_log_format(ab, "<no memory>");
return;
@@ -841,7 +870,7 @@ void audit_log_end(struct audit_buffer *ab)
ab->skb = NULL;
wake_up_interruptible(&kauditd_wait);
} else {
- printk("%s\n", ab->skb->data + NLMSG_SPACE(0));
+ printk(KERN_NOTICE "%s\n", ab->skb->data + NLMSG_SPACE(0));
}
}
audit_buffer_free(ab);
@@ -850,12 +879,13 @@ void audit_log_end(struct audit_buffer *ab)
/* Log an audit record. 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, int type, const char *fmt, ...)
+void audit_log(struct audit_context *ctx, int gfp_mask, int type,
+ const char *fmt, ...)
{
struct audit_buffer *ab;
va_list args;
- ab = audit_log_start(ctx, type);
+ ab = audit_log_start(ctx, gfp_mask, type);
if (ab) {
va_start(args, fmt);
audit_log_vformat(ab, fmt, args);