From 53e71e47d6b81650d26ec33a58d0dca24c7ffb2c Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Tue, 4 Oct 2016 18:56:45 +0200
Subject: [PATCH] unescape: avoid integer overflow

CVE: CVE-2016-8622
Upstream-Status: Backport

Bug: https://curl.haxx.se/docs/adv_20161102H.html
Reported-by: Cure53

Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>

diff -ruN a/docs/libcurl/curl_easy_unescape.3 b/docs/libcurl/curl_easy_unescape.3
--- a/docs/libcurl/curl_easy_unescape.3	2016-02-03 00:08:02.000000000 +0100
+++ b/docs/libcurl/curl_easy_unescape.3	2016-11-07 09:25:45.999933275 +0100
@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -40,7 +40,10 @@
 
 If \fBoutlength\fP is non-NULL, the function will write the length of the
 returned string in the integer it points to. This allows an escaped string
-containing %00 to still get used properly after unescaping.
+containing %00 to still get used properly after unescaping. Since this is a
+pointer to an \fIint\fP type, it can only return a value up to INT_MAX so no
+longer string can be unescaped if the string length is returned in this
+parameter.
 
 You must \fIcurl_free(3)\fP the returned string when you're done with it.
 .SH AVAILABILITY
diff -ruN a/lib/dict.c b/lib/dict.c
--- a/lib/dict.c	2016-02-03 00:02:44.000000000 +0100
+++ b/lib/dict.c	2016-11-07 09:25:45.999933275 +0100
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -52,7 +52,7 @@
 #include <curl/curl.h>
 #include "transfer.h"
 #include "sendf.h"
-
+#include "escape.h"
 #include "progress.h"
 #include "strequal.h"
 #include "dict.h"
@@ -96,12 +96,12 @@
   char *newp;
   char *dictp;
   char *ptr;
-  int len;
+  size_t len;
   char ch;
   int olen=0;
 
-  newp = curl_easy_unescape(data, inputbuff, 0, &len);
-  if(!newp)
+  CURLcode result = Curl_urldecode(data, inputbuff, 0, &newp, &len, FALSE);
+  if(!newp || result)
     return NULL;
 
   dictp = malloc(((size_t)len)*2 + 1); /* add one for terminating zero */
diff -ruN a/lib/escape.c b/lib/escape.c
--- a/lib/escape.c	2016-02-05 10:02:03.000000000 +0100
+++ b/lib/escape.c	2016-11-07 09:29:43.073671606 +0100
@@ -217,8 +217,14 @@
                                 FALSE);
   if(res)
     return NULL;
-  if(olen)
-    *olen = curlx_uztosi(outputlen);
+
+    if(olen) {
+      if(outputlen <= (size_t) INT_MAX)
+        *olen = curlx_uztosi(outputlen);
+      else
+        /* too large to return in an int, fail! */
+        Curl_safefree(str);
+    }
   return str;
 }