diff -Nru xen-3.1.0-src.orig/tools/libxc/xc_core.c xen-3.1.0-src/tools/libxc/xc_core.c
--- xen-3.1.0-src.orig/tools/libxc/xc_core.c	2007-05-18 16:45:21.000000000 +0200
+++ xen-3.1.0-src/tools/libxc/xc_core.c	2007-06-22 18:47:13.000000000 +0200
@@ -192,12 +192,14 @@
     if ( sheaders->num == sheaders->num_max )
     {
         Elf64_Shdr *shdrs;
-        if ( sheaders->num_max + SHDR_INC < sheaders->num_max )
+
+        sheaders->num_max += SHDR_INC;
+        if ( sheaders->num_max < SHDR_INC )
         {
             errno = E2BIG;
             return NULL;
         }
-        sheaders->num_max += SHDR_INC;
+	
         shdrs = realloc(sheaders->shdrs,
                         sizeof(sheaders->shdrs[0]) * sheaders->num_max);
         if ( shdrs == NULL )