Index: main/manager.c
===================================================================
--- main/manager.c	(revision 317194)
+++ main/manager.c	(working copy)
@@ -2990,12 +2990,14 @@
 			char *buf;
 			size_t l;
 
-			if ((l = lseek(ss.fd, 0, SEEK_END)) > 0) {
-				if (MAP_FAILED == (buf = mmap(NULL, l + 1, PROT_READ | PROT_WRITE, MAP_SHARED, ss.fd, 0))) {
+			/* Make sure we have room at the end for a terminating NULL */
+			fputc(0, ss.f);
+
+			if ((l = ftell(ss.f))) {
+				if (MAP_FAILED == (buf = mmap(NULL, l, PROT_READ | PROT_WRITE, MAP_PRIVATE, ss.fd, 0))) {
 					ast_log(LOG_WARNING, "mmap failed.  Manager request output was not processed\n");
 				} else {
 					char *tmpbuf;
-					buf[l] = '\0';
 					if (format == FORMAT_XML)
 						tmpbuf = xml_translate(buf, params);
 					else if (format == FORMAT_HTML)
@@ -3016,7 +3018,7 @@
 						free(tmpbuf);
 					free(s->outputstr);
 					s->outputstr = NULL;
-					munmap(buf, l + 1);
+					munmap(buf, l);
 				}
 			}
 			fclose(ss.f);