Set close-on-exec flag in most places where file descriptors are

opened in our libraries (in case another application thread spawns a
new process) and in the KDC programs (in case a plugin library spawns
a new process).

Checked calls to: open fopen THREEPARAMOPEN mkstemp socket accept dup
dup2 pipe.  In: util lib plugins kdc kadmin/server krb524.

The various programs are less critical than the libraries, as any
well-written plugin that spawns a new process should close all file
descriptors it doesn't need to communicate with the new process.

This approach also isn't bulletproof, as the call to set the
close-on-exec flag is necessarily a separate call from creating the
file descriptor, and the fork call could happen in between them.  So
plugins should be careful regardless of this patch; it will only
reduce the window of potential lossage should a plugin be poorly
written.  (AFAIK there are currently no plugins that spawn processes
where this would be a problem.)

Update dependencies.

ticket: 5561

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@20143 dc483132-0cff-0310-8789-dd5450dbe970

1 files changed, 5 insertions, 6 deletions

diff --git a/src/lib/crypto/prng.c b/src/lib/crypto/prng.c
index e1e34a2c3f..8de199885b 100644
--- a/src/lib/crypto/prng.c
+++ b/src/lib/crypto/prng.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2001, 2002, 2004 by the Massachusetts Institute of Technology.
+ * Copyright (C) 2001, 2002, 2004, 2007 by the Massachusetts Institute of Technology.
  * All rights reserved.
  *
  * 
@@ -166,11 +166,10 @@ read_entropy_from_device (krb5_context context, const char *device)
   fd = open (device, O_RDONLY);
   if (fd == -1)
     return 0;
-  if (fstat (fd, &sb) == -1)
-    return 0;
-  if (S_ISREG(sb.st_mode)) {
-    close(fd);
-    return 0;
+  set_cloexec_fd(fd);
+  if (fstat (fd, &sb) == -1 || S_ISREG(sb.st_mode)) {
+      close(fd);
+      return 0;
   }
 
   for (bp = &buf, left = sizeof (buf); left > 0;) {