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Diffstat (limited to 'kernel/audit.c')
-rw-r--r--kernel/audit.c434
1 files changed, 178 insertions, 256 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index 801c946dd24..c8555b18021 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -66,10 +66,11 @@
* (Initialization happens after skb_init is called.) */
static int audit_initialized;
-/* 0 - no auditing
- * 1 - auditing enabled
- * 2 - auditing enabled and configuration is locked/unchangeable. */
+#define AUDIT_OFF 0
+#define AUDIT_ON 1
+#define AUDIT_LOCKED 2
int audit_enabled;
+int audit_ever_enabled;
/* Default state when kernel boots without any parameters. */
static int audit_default;
@@ -152,8 +153,10 @@ struct audit_buffer {
static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
{
- struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
- nlh->nlmsg_pid = pid;
+ if (ab) {
+ struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
+ nlh->nlmsg_pid = pid;
+ }
}
void audit_panic(const char *message)
@@ -163,7 +166,8 @@ void audit_panic(const char *message)
case AUDIT_FAIL_SILENT:
break;
case AUDIT_FAIL_PRINTK:
- printk(KERN_ERR "audit: %s\n", message);
+ if (printk_ratelimit())
+ printk(KERN_ERR "audit: %s\n", message);
break;
case AUDIT_FAIL_PANIC:
panic("audit: %s\n", message);
@@ -231,161 +235,107 @@ void audit_log_lost(const char *message)
}
if (print) {
- 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);
+ 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_set_rate_limit(int limit, uid_t loginuid, u32 sid)
+static int audit_log_config_change(char *function_name, int new, int old,
+ uid_t loginuid, u32 sid, int allow_changes)
{
- int res, rc = 0, old = audit_rate_limit;
-
- /* check if we are locked */
- if (audit_enabled == 2)
- res = 0;
- else
- res = 1;
+ 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 by auid=%u", function_name, new,
+ old, loginuid);
if (sid) {
char *ctx = NULL;
u32 len;
- if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_rate_limit=%d old=%d by auid=%u"
- " subj=%s res=%d",
- limit, old, loginuid, ctx, res);
+
+ rc = selinux_sid_to_string(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);
kfree(ctx);
- } else
- res = 0; /* Something weird, deny request */
+ }
}
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_rate_limit=%d old=%d by auid=%u res=%d",
- limit, old, loginuid, res);
-
- /* If we are allowed, make the change */
- if (res == 1)
- audit_rate_limit = limit;
- /* Not allowed, update reason */
- else if (rc == 0)
- rc = -EPERM;
+ audit_log_format(ab, " res=%d", allow_changes);
+ audit_log_end(ab);
return rc;
}
-static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid)
+static int audit_do_config_change(char *function_name, int *to_change,
+ int new, uid_t loginuid, u32 sid)
{
- int res, rc = 0, old = audit_backlog_limit;
+ int allow_changes, rc = 0, old = *to_change;
/* check if we are locked */
- if (audit_enabled == 2)
- res = 0;
+ if (audit_enabled == AUDIT_LOCKED)
+ allow_changes = 0;
else
- res = 1;
+ allow_changes = 1;
- if (sid) {
- char *ctx = NULL;
- u32 len;
- if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_backlog_limit=%d old=%d by auid=%u"
- " subj=%s res=%d",
- limit, old, loginuid, ctx, res);
- kfree(ctx);
- } else
- res = 0; /* Something weird, deny request */
+ if (audit_enabled != AUDIT_OFF) {
+ rc = audit_log_config_change(function_name, new, old,
+ loginuid, sid, allow_changes);
+ if (rc)
+ allow_changes = 0;
}
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_backlog_limit=%d old=%d by auid=%u res=%d",
- limit, old, loginuid, res);
/* If we are allowed, make the change */
- if (res == 1)
- audit_backlog_limit = limit;
+ if (allow_changes == 1)
+ *to_change = new;
/* Not allowed, update reason */
else if (rc == 0)
rc = -EPERM;
return rc;
}
-static int audit_set_enabled(int state, uid_t loginuid, u32 sid)
+static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid)
+{
+ return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
+ limit, loginuid, sid);
+}
+
+static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid)
{
- int res, rc = 0, old = audit_enabled;
+ return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
+ limit, loginuid, sid);
+}
- if (state < 0 || state > 2)
+static int audit_set_enabled(int state, uid_t loginuid, u32 sid)
+{
+ int rc;
+ if (state < AUDIT_OFF || state > AUDIT_LOCKED)
return -EINVAL;
- /* check if we are locked */
- if (audit_enabled == 2)
- res = 0;
- else
- res = 1;
+ rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
+ loginuid, sid);
- if (sid) {
- char *ctx = NULL;
- u32 len;
- if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_enabled=%d old=%d by auid=%u"
- " subj=%s res=%d",
- state, old, loginuid, ctx, res);
- kfree(ctx);
- } else
- res = 0; /* Something weird, deny request */
- }
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_enabled=%d old=%d by auid=%u res=%d",
- state, old, loginuid, res);
+ if (!rc)
+ audit_ever_enabled |= !!state;
- /* If we are allowed, make the change */
- if (res == 1)
- audit_enabled = state;
- /* Not allowed, update reason */
- else if (rc == 0)
- rc = -EPERM;
return rc;
}
static int audit_set_failure(int state, uid_t loginuid, u32 sid)
{
- int res, rc = 0, old = audit_failure;
-
if (state != AUDIT_FAIL_SILENT
&& state != AUDIT_FAIL_PRINTK
&& state != AUDIT_FAIL_PANIC)
return -EINVAL;
- /* check if we are locked */
- if (audit_enabled == 2)
- res = 0;
- else
- res = 1;
-
- if (sid) {
- char *ctx = NULL;
- u32 len;
- if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_failure=%d old=%d by auid=%u"
- " subj=%s res=%d",
- state, old, loginuid, ctx, res);
- kfree(ctx);
- } else
- res = 0; /* Something weird, deny request */
- }
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_failure=%d old=%d by auid=%u res=%d",
- state, old, loginuid, res);
-
- /* If we are allowed, make the change */
- if (res == 1)
- audit_failure = state;
- /* Not allowed, update reason */
- else if (rc == 0)
- rc = -EPERM;
- return rc;
+ return audit_do_config_change("audit_failure", &audit_failure, state,
+ loginuid, sid);
}
static int kauditd_thread(void *dummy)
@@ -405,7 +355,11 @@ static int kauditd_thread(void *dummy)
audit_pid = 0;
}
} else {
- printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0));
+ if (printk_ratelimit())
+ printk(KERN_NOTICE "%s\n", skb->data +
+ NLMSG_SPACE(0));
+ else
+ audit_log_lost("printk limit exceeded\n");
kfree_skb(skb);
}
} else {
@@ -573,6 +527,33 @@ 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 sid)
+{
+ int rc = 0;
+ char *ctx = NULL;
+ u32 len;
+
+ if (!audit_enabled) {
+ *ab = NULL;
+ return rc;
+ }
+
+ *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
+ audit_log_format(*ab, "user pid=%d uid=%u auid=%u",
+ pid, uid, auid);
+ if (sid) {
+ rc = selinux_sid_to_string(sid, &ctx, &len);
+ if (rc)
+ audit_log_format(*ab, " ssid=%u", sid);
+ else
+ audit_log_format(*ab, " subj=%s", ctx);
+ kfree(ctx);
+ }
+
+ return rc;
+}
+
static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
u32 uid, pid, seq, sid;
@@ -583,7 +564,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
u16 msg_type = nlh->nlmsg_type;
uid_t loginuid; /* loginuid of sender */
struct audit_sig_info *sig_data;
- char *ctx;
+ char *ctx = NULL;
u32 len;
err = audit_netlink_ok(skb, msg_type);
@@ -634,23 +615,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (err < 0) return err;
}
if (status_get->mask & AUDIT_STATUS_PID) {
- int old = audit_pid;
- if (sid) {
- if ((err = selinux_sid_to_string(
- sid, &ctx, &len)))
- return err;
- else
- audit_log(NULL, GFP_KERNEL,
- AUDIT_CONFIG_CHANGE,
- "audit_pid=%d old=%d by auid=%u subj=%s",
- status_get->pid, old,
- loginuid, ctx);
- kfree(ctx);
- } else
- audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
- "audit_pid=%d old=%d by auid=%u",
- status_get->pid, old, loginuid);
- audit_pid = status_get->pid;
+ int new_pid = status_get->pid;
+
+ if (audit_enabled != AUDIT_OFF)
+ audit_log_config_change("audit_pid", new_pid,
+ audit_pid, loginuid,
+ sid, 1);
+
+ audit_pid = new_pid;
}
if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
err = audit_set_rate_limit(status_get->rate_limit,
@@ -673,64 +645,35 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (err)
break;
}
- ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
- if (ab) {
- audit_log_format(ab,
- "user pid=%d uid=%u auid=%u",
- pid, uid, loginuid);
- if (sid) {
- if (selinux_sid_to_string(
- sid, &ctx, &len)) {
- audit_log_format(ab,
- " ssid=%u", sid);
- /* Maybe call audit_panic? */
- } else
- audit_log_format(ab,
- " subj=%s", ctx);
- kfree(ctx);
- }
- if (msg_type != AUDIT_USER_TTY)
- audit_log_format(ab, " msg='%.1024s'",
- (char *)data);
- else {
- int size;
-
- audit_log_format(ab, " msg=");
- size = nlmsg_len(nlh);
- audit_log_n_untrustedstring(ab, size,
- data);
- }
- audit_set_pid(ab, pid);
- audit_log_end(ab);
+ audit_log_common_recv_msg(&ab, msg_type, pid, uid,
+ loginuid, sid);
+
+ if (msg_type != AUDIT_USER_TTY)
+ audit_log_format(ab, " msg='%.1024s'",
+ (char *)data);
+ else {
+ int size;
+
+ audit_log_format(ab, " msg=");
+ size = nlmsg_len(nlh);
+ audit_log_n_untrustedstring(ab, size,
+ data);
}
+ audit_set_pid(ab, pid);
+ audit_log_end(ab);
}
break;
case AUDIT_ADD:
case AUDIT_DEL:
if (nlmsg_len(nlh) < sizeof(struct audit_rule))
return -EINVAL;
- if (audit_enabled == 2) {
- ab = audit_log_start(NULL, GFP_KERNEL,
- AUDIT_CONFIG_CHANGE);
- if (ab) {
- audit_log_format(ab,
- "pid=%d uid=%u auid=%u",
- pid, uid, loginuid);
- if (sid) {
- if (selinux_sid_to_string(
- sid, &ctx, &len)) {
- audit_log_format(ab,
- " ssid=%u", sid);
- /* Maybe call audit_panic? */
- } else
- audit_log_format(ab,
- " subj=%s", ctx);
- kfree(ctx);
- }
- audit_log_format(ab, " audit_enabled=%d res=0",
- audit_enabled);
- audit_log_end(ab);
- }
+ if (audit_enabled == AUDIT_LOCKED) {
+ audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
+ uid, loginuid, sid);
+
+ audit_log_format(ab, " audit_enabled=%d res=0",
+ audit_enabled);
+ audit_log_end(ab);
return -EPERM;
}
/* fallthrough */
@@ -743,28 +686,13 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
case AUDIT_DEL_RULE:
if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
return -EINVAL;
- if (audit_enabled == 2) {
- ab = audit_log_start(NULL, GFP_KERNEL,
- AUDIT_CONFIG_CHANGE);
- if (ab) {
- audit_log_format(ab,
- "pid=%d uid=%u auid=%u",
- pid, uid, loginuid);
- if (sid) {
- if (selinux_sid_to_string(
- sid, &ctx, &len)) {
- audit_log_format(ab,
- " ssid=%u", sid);
- /* Maybe call audit_panic? */
- } else
- audit_log_format(ab,
- " subj=%s", ctx);
- kfree(ctx);
- }
- audit_log_format(ab, " audit_enabled=%d res=0",
- audit_enabled);
- audit_log_end(ab);
- }
+ if (audit_enabled == AUDIT_LOCKED) {
+ audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
+ uid, loginuid, sid);
+
+ audit_log_format(ab, " audit_enabled=%d res=0",
+ audit_enabled);
+ audit_log_end(ab);
return -EPERM;
}
/* fallthrough */
@@ -775,19 +703,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
break;
case AUDIT_TRIM:
audit_trim_trees();
- ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
- if (!ab)
- break;
- audit_log_format(ab, "auid=%u", loginuid);
- if (sid) {
- u32 len;
- ctx = NULL;
- if (selinux_sid_to_string(sid, &ctx, &len))
- audit_log_format(ab, " ssid=%u", sid);
- else
- audit_log_format(ab, " subj=%s", ctx);
- kfree(ctx);
- }
+
+ audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
+ uid, loginuid, sid);
+
audit_log_format(ab, " op=trim res=1");
audit_log_end(ab);
break;
@@ -817,22 +736,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
/* OK, here comes... */
err = audit_tag_tree(old, new);
- ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
- if (!ab) {
- kfree(old);
- kfree(new);
- break;
- }
- audit_log_format(ab, "auid=%u", loginuid);
- if (sid) {
- u32 len;
- ctx = NULL;
- if (selinux_sid_to_string(sid, &ctx, &len))
- audit_log_format(ab, " ssid=%u", sid);
- else
- audit_log_format(ab, " subj=%s", ctx);
- kfree(ctx);
- }
+ audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
+ uid, loginuid, sid);
+
audit_log_format(ab, " op=make_equiv old=");
audit_log_untrustedstring(ab, old);
audit_log_format(ab, " new=");
@@ -965,6 +871,7 @@ static int __init audit_init(void)
skb_queue_head_init(&audit_skb_queue);
audit_initialized = 1;
audit_enabled = audit_default;
+ audit_ever_enabled |= !!audit_default;
/* Register the callback with selinux. This callback will be invoked
* when a new policy is loaded. */
@@ -992,8 +899,10 @@ static int __init audit_enable(char *str)
printk(KERN_INFO "audit: %s%s\n",
audit_default ? "enabled" : "disabled",
audit_initialized ? "" : " (after initialization)");
- if (audit_initialized)
+ if (audit_initialized) {
audit_enabled = audit_default;
+ audit_ever_enabled |= !!audit_default;
+ }
return 1;
}
@@ -1130,7 +1039,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
{
struct audit_buffer *ab = NULL;
struct timespec t;
- unsigned int serial;
+ unsigned int uninitialized_var(serial);
int reserve;
unsigned long timeout_start = jiffies;
@@ -1164,7 +1073,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
remove_wait_queue(&audit_backlog_wait, &wait);
continue;
}
- if (audit_rate_check())
+ if (audit_rate_check() && printk_ratelimit())
printk(KERN_WARNING
"audit: audit_backlog=%d > "
"audit_backlog_limit=%d\n",
@@ -1249,6 +1158,7 @@ static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
goto out;
len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
}
+ va_end(args2);
if (len > 0)
skb_put(skb, len);
out:
@@ -1350,6 +1260,21 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
}
/**
+ * 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; p++) {
+ if (*p == '"' || *p < 0x21 || *p > 0x7f)
+ return 1;
+ }
+ return 0;
+}
+
+/**
* audit_log_n_untrustedstring - log a string that may contain random characters
* @ab: audit_buffer
* @len: lenth of string (not including trailing null)
@@ -1363,19 +1288,13 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
* The caller specifies the number of characters in the string to log, which may
* or may not be the entire string.
*/
-const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len,
- const char *string)
+void audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len,
+ const char *string)
{
- const unsigned char *p;
-
- for (p = string; p < (const unsigned char *)string + len && *p; p++) {
- if (*p == '"' || *p < 0x21 || *p > 0x7f) {
- audit_log_hex(ab, string, len);
- return string + len + 1;
- }
- }
- audit_log_n_string(ab, len, string);
- return p + 1;
+ if (audit_string_contains_control(string, len))
+ audit_log_hex(ab, string, len);
+ else
+ audit_log_n_string(ab, len, string);
}
/**
@@ -1386,9 +1305,9 @@ const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len,
* Same as audit_log_n_untrustedstring(), except that strlen is used to
* determine string length.
*/
-const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
+void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
{
- return audit_log_n_untrustedstring(ab, strlen(string), string);
+ audit_log_n_untrustedstring(ab, strlen(string), string);
}
/* This is a helper-function to print the escaped d_path */
@@ -1437,8 +1356,11 @@ void audit_log_end(struct audit_buffer *ab)
skb_queue_tail(&audit_skb_queue, ab->skb);
ab->skb = NULL;
wake_up_interruptible(&kauditd_wait);
+ } else if (printk_ratelimit()) {
+ struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
+ printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, ab->skb->data + NLMSG_SPACE(0));
} else {
- printk(KERN_NOTICE "%s\n", ab->skb->data + NLMSG_SPACE(0));
+ audit_log_lost("printk limit exceeded\n");
}
}
audit_buffer_free(ab);
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 22:14:47 +0000