From 6654fbcb3b5f4e137cedc951e83cc244c106455b Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@dragonflybsd.org>
Date: Thu, 27 Nov 2003 19:57:37 +0000
Subject: [PATCH] Fix a DOS in rfork().  Disallow kernel-only flags.

Taken-from: FreeBSD-4.x kern_fork.c 1.72.2.16 and unistd.h 1.22.2.3
---
 sys/kern/kern_fork.c | 6 +++++-
 sys/sys/unistd.h     | 4 +++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 841a377f12..cd57b0bf91 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -37,7 +37,7 @@
  *
  *	@(#)kern_fork.c	8.6 (Berkeley) 4/8/94
  * $FreeBSD: src/sys/kern/kern_fork.c,v 1.72.2.13 2003/06/06 20:21:32 tegge Exp $
- * $DragonFly: src/sys/kern/kern_fork.c,v 1.16 2003/11/05 23:26:20 dillon Exp $
+ * $DragonFly: src/sys/kern/kern_fork.c,v 1.17 2003/11/27 19:57:37 dillon Exp $
  */
 
 #include "opt_ktrace.h"
@@ -124,6 +124,10 @@ rfork(struct rfork_args *uap)
 	struct proc *p2;
 	int error;
 
+	/* Don't allow kernel only flags */
+	if ((uap->flags & RFKERNELONLY) != 0)
+		return (EINVAL);
+
 	error = fork1(p, uap->flags, &p2);
 	if (error == 0) {
 		start_forked_proc(p, p2);
diff --git a/sys/sys/unistd.h b/sys/sys/unistd.h
index 1a60823727..76ce150bde 100644
--- a/sys/sys/unistd.h
+++ b/sys/sys/unistd.h
@@ -32,7 +32,7 @@
  *
  *	@(#)unistd.h	8.2 (Berkeley) 1/7/94
  * $FreeBSD: src/sys/sys/unistd.h,v 1.22.2.2 2000/08/22 01:46:30 jhb Exp $
- * $DragonFly: src/sys/sys/unistd.h,v 1.2 2003/06/17 04:28:59 dillon Exp $
+ * $DragonFly: src/sys/sys/unistd.h,v 1.3 2003/11/27 19:57:36 dillon Exp $
  */
 
 #ifndef _SYS_UNISTD_H_
@@ -219,6 +219,8 @@
 #define RFSIGSHARE	(1<<14)	/* share signal handlers */
 #define RFLINUXTHPN     (1<<16) /* do linux clone exit parent notification */
 #define RFPPWAIT	(1<<31) /* parent sleeps until child exits (vfork) */
+#define RFKERNELONLY	RFPPWAIT
+
 
 #endif /* !_POSIX_SOURCE */
 
-- 
2.41.0