Backport patch from pcre 6.2 to fix integer overflows in quantifier

parsing:

* srclib/pcre/pcre.c (read_repeat_counts): Check for integer overflow.

Obtained from: pcre 6.2 upstream

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@233493 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/CHANGES b/CHANGES
index 8a6571b44f74a16ca7fd3ee0df1660cd39f40e96..81d92e1ce1338f80b0548ef24a3203ecd5720698 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,11 @@
                                                         -*- coding: utf-8 -*-
 Changes with Apache 2.3.0
 
+  *) SECURITY: CAN-2005-2491 (cve.mitre.org): 
+     Fix integer overflows in PCRE in quantifier parsing which could
+     be triggered by a local user through use of a carefully-crafted 
+     regex in an .htaccess file.  [Philip Hazel]
+
   *) mod_proxy/mod_proxy_balancer: Provide a simple, functional
      interface to add additional balancer lb selection methods
      without requiring code changes to mod_proxy/mod_proxy_balancer;

diff --git a/srclib/pcre/pcre.c b/srclib/pcre/pcre.c
index dc013faf021014d9b70f76ae41597067a7764202..4936323a3b42acd59dfddf45e054e0e268af3521 100644 (file)
--- a/srclib/pcre/pcre.c
+++ b/srclib/pcre/pcre.c
@@ -1247,7 +1247,18 @@ read_repeat_counts(const uschar *p, int *minp, int *maxp, const char **errorptr)
 int min = 0;
 int max = -1;
 
+/* Read the minimum value and do a paranoid check: a negative value indicates
+an integer overflow. */
+
 while ((digitab[*p] & ctype_digit) != 0) min = min * 10 + *p++ - '0';
+if (min < 0 || min > 65535)
+  {
+  *errorptr = ERR5;
+  return p;
+  }
+
+/* Read the maximum value if there is one, and again do a paranoid on its size.
+Also, max must not be less than min. */
 
 if (*p == '}') max = min; else
   {
@@ -1255,6 +1266,11 @@ if (*p == '}') max = min; else
     {
     max = 0;
     while((digitab[*p] & ctype_digit) != 0) max = max * 10 + *p++ - '0';
+    if (max < 0 || max > 65535)
+      {
+      *errorptr = ERR5;
+      return p;
+      }
     if (max < min)
       {
       *errorptr = ERR4;
@@ -1263,16 +1279,11 @@ if (*p == '}') max = min; else
     }
   }
 
-/* Do paranoid checks, then fill in the required variables, and pass back the
-pointer to the terminating '}'. */
+/* Fill in the required variables, and pass back the pointer to the terminating
+'}'. */
 
-if (min > 65535 || max > 65535)
-  *errorptr = ERR5;
-else
-  {
-  *minp = min;
-  *maxp = max;
-  }
+*minp = min;
+*maxp = max;
 return p;
 }