From e4bf3807ae2fa8b4491f0ed336bc42541faf2a55 Mon Sep 17 00:00:00 2001
From: Matthieu Herrb <matthieu.herrb@laas.fr>
Date: Mon, 17 Oct 2011 20:27:35 +0000
Subject: Fix CVE-2011-4029: File permission change vulnerability.

Use fchmod() to change permissions of the lock file instead
of chmod(), thus avoid the race that can be exploited to set
a symbolic link to any file or directory in the system.

Signed-off-by: Matthieu Herrb <matthieu.herrb@laas.fr>
Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
(cherry picked from commit b67581cf825940fdf52bf2e0af4330e695d724a4)
---
diff --git a/os/utils.c b/os/utils.c
index fad72b4..da23589 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -306,7 +306,7 @@ LockServer(void)
     FatalError("Could not create lock file in %s\n", tmp);
   (void) sprintf(pid_str, "%10ld\n", (long)getpid());
   (void) write(lfd, pid_str, 11);
-  (void) chmod(tmp, 0444);
+  (void) fchmod(lfd, 0444);
   (void) close(lfd);
 
   /*
--
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