fix: Add a 1MB limit to lttng_strlen_user_inatomic

[lttng-modules.git] / probes / lttng-probe-user.c

diff --git a/probes/lttng-probe-user.c b/probes/lttng-probe-user.c
index 099a66b229a46fcc90f7b5fd7e504a3806d7d0e6..57dd33e198a780bc341659d175cce016b2d00da8 100644 (file)
--- a/probes/lttng-probe-user.c
+++ b/probes/lttng-probe-user.c
@@ -1,27 +1,17 @@
-/*
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
  * lttng-probe-user.c
  *
  * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <linux/uaccess.h>
 #include <linux/module.h>
+#include <wrapper/uaccess.h>
 #include <probes/lttng-probe-user.h>
 
+#define LTTNG_MAX_USER_STRING_LEN 1048576 /* 1MB */
+
 /*
  * Calculate string length. Include final null terminating character if there is
  * one, or ends at first fault. Disabling page faults ensures that we can safely
@@ -43,7 +33,7 @@ long lttng_strlen_user_inatomic(const char *addr)
                char v;
                unsigned long ret;
 
-               if (unlikely(!access_ok(VERIFY_READ,
+               if (unlikely(!lttng_access_ok(VERIFY_READ,
                                (__force const char __user *) addr,
                                sizeof(v))))
                        break;
@@ -53,6 +43,8 @@ long lttng_strlen_user_inatomic(const char *addr)
                if (unlikely(ret > 0))
                        break;
                count++;
+               if (unlikely(count > LTTNG_MAX_USER_STRING_LEN))
+                       break;
                if (unlikely(!v))
                        break;
                addr++;