From b440f05ba475f60fec7155b56d8c85a8302e96a3 Mon Sep 17 00:00:00 2001
From: delphij <delphij@FreeBSD.org>
Date: Tue, 1 Sep 2015 06:32:02 +0000
Subject: [PATCH] Check and fail if drop of privileges failed.

MFC after:	2 weeks
---
 usr.sbin/trpt/trpt.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/usr.sbin/trpt/trpt.c b/usr.sbin/trpt/trpt.c
index fbdc4deb344e..d85d41d42275 100644
--- a/usr.sbin/trpt/trpt.c
+++ b/usr.sbin/trpt/trpt.c
@@ -148,7 +148,8 @@ main(int argc, char **argv)
 		 * Discard setgid privileges if not the running kernel so that
 		 * bad guys can't print interesting stuff from kernel memory.
 		 */
-		setgid(getgid());
+		if (setgid(getgid()) != 0)
+			err(1, "setgid");
 	}
 	else
 		syst = getbootfile();
@@ -157,7 +158,8 @@ main(int argc, char **argv)
 		errx(1, "%s: no namelist", syst);
 	if ((memf = open(core, O_RDONLY)) < 0)
 		err(2, "%s", core);
-	setgid(getgid());
+	if (setgid(getgid()) != 0)
+		err(1, "setgid");
 	if (kflag)
 		errx(1, "can't do core files yet");
 	(void)klseek(memf, (off_t)nl[N_TCP_DEBX].n_value, L_SET);