From cf399edbc85b744450dfdb02b37efe37d1674cd6 Mon Sep 17 00:00:00 2001
From: YASUOKA Masahiko <yasuoka@cvs.openbsd.org>
Date: Sun, 31 Mar 2019 03:36:19 +0000
Subject: Avoid calling dup2(oldd, newd) when oldd == newd.  In that case the
 descriptor keeps CLOEXEC flag then it will be closed unexpectedly by exec().

ok tedu florian
---
 usr.sbin/ldpd/ldpd.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

(limited to 'usr.sbin/ldpd')

diff --git a/usr.sbin/ldpd/ldpd.c b/usr.sbin/ldpd/ldpd.c
index 7425d2030e5..d074b9e2329 100644
--- a/usr.sbin/ldpd/ldpd.c
+++ b/usr.sbin/ldpd/ldpd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ldpd.c,v 1.63 2019/01/23 02:02:04 dlg Exp $ */
+/*	$OpenBSD: ldpd.c,v 1.64 2019/03/31 03:36:18 yasuoka Exp $ */
 
 /*
  * Copyright (c) 2013, 2016 Renato Westphal <renato@openbsd.org>
@@ -23,6 +23,7 @@
 #include <sys/wait.h>
 #include <err.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -330,7 +331,10 @@ start_child(enum ldpd_process p, char *argv0, int fd, int debug, int verbose,
 		return (pid);
 	}
 
-	if (dup2(fd, 3) == -1)
+	if (fd != 3) {
+		if (dup2(fd, 3) == -1)
+			fatal("cannot setup imsg fd");
+	} else if (fcntl(fd, F_SETFD, 0) == -1)
 		fatal("cannot setup imsg fd");
 
 	argv[argc++] = argv0;
-- 
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