iget: stop EFS from using iget() and read_inode()
[pandora-kernel.git] / kernel / audit.c
index 801c946..c8555b1 100644 (file)
  * (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:
@@ -1349,6 +1259,21 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
        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; 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
@@ -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);