Merge r1230065 from trunk (adapted to avoid MMN change):

SECURITY (CVE-2012-0031): Fix possible crash on shutdown if a child
changes the sb_type field in the scoreboard.  Since unprivileged
children should not be able to affect the parent in this way, this is
treated as a Low severity security issue.

Thanks to "halfdog" <me halfdog.net> for reporting this issue.

* server/scoreboard.c (ap_cleanup_scoreboard, ap_create_scoreboard):
  Use a static global to store an authoritative copy of the scoreboard
  type.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1230069 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/CHANGES b/CHANGES
index 1acf70e267a07e82246989a548adb2f0d6ef796c..7a975e68d6e7268619c764de19e028dadd00be90 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,10 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache 2.4.0
 
+  *) SECURITY (CVE-2012-0031): Fix scoreboard issue which could allow
+     an unprivileged child process could cause the parent to crash at
+     shutdown rather than terminate cleanly.  [Joe Orton]
+
   *) mod_ssl: Fix compilation with xlc on AIX. PR 52394. [Stefan Fritsch]
 
   *) mod_log_config: Fix segfault when trying to log a nameless, valueless

diff --git a/server/scoreboard.c b/server/scoreboard.c
index 72aa07045054db9b7a8d133d19df7982e0e009dd..b3d553f437c212afdd94f9bf21a4f745e8144da3 100644 (file)
--- a/server/scoreboard.c
+++ b/server/scoreboard.c
@@ -42,6 +42,7 @@
 
 AP_DECLARE_DATA scoreboard *ap_scoreboard_image = NULL;
 AP_DECLARE_DATA const char *ap_scoreboard_fname = NULL;
+static ap_scoreboard_e scoreboard_type;
 
 const char * ap_set_scoreboard(cmd_parms *cmd, void *dummy,
                                const char *arg)
@@ -276,7 +277,7 @@ apr_status_t ap_cleanup_scoreboard(void *d)
     if (ap_scoreboard_image == NULL) {
         return APR_SUCCESS;
     }
-    if (ap_scoreboard_image->global->sb_type == SB_SHARED) {
+    if (scoreboard_type == SB_SHARED) {
         ap_cleanup_shared_mem(NULL);
     }
     else {
@@ -329,7 +330,7 @@ int ap_create_scoreboard(apr_pool_t *p, ap_scoreboard_e sb_type)
         ap_init_scoreboard(sb_mem);
     }
 
-    ap_scoreboard_image->global->sb_type = sb_type;
+    ap_scoreboard_image->global->sb_type = scoreboard_type = sb_type;
     ap_scoreboard_image->global->running_generation = 0;
     ap_scoreboard_image->global->restart_time = apr_time_now();