From d21c8fc44b0717bcc6076aea99277da169deb37e Mon Sep 17 00:00:00 2001
From: Jesse Smith <jsmith@resonatingmedia.com>
Date: Tue, 20 Feb 2018 19:37:29 -0400
Subject: [PATCH] Perform error check on setuid() call in shutdown as manual
 page suggests.

---
 src/shutdown.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/shutdown.c b/src/shutdown.c
index d9ac9f4..f85bc38 100644
--- a/src/shutdown.c
+++ b/src/shutdown.c
@@ -498,7 +498,15 @@ int main(int argc, char **argv)
 	int			user_ok = 0;
 
 	/* We can be installed setuid root (executable for a special group) */
-	setuid(geteuid());
+	/* 
+        This way is risky, do error check on setuid call.
+        setuid(geteuid());
+        */
+        errno = 0;
+        if (setuid(geteuid()) == -1) {
+            fprintf(stderr, "%s (%d): %s\n", __FILE__, __LINE__, strerror(errno));
+            abort();
+	}
 
 	if (getuid() != 0) {
   		fprintf(stderr, "shutdown: you must be root to do that!\n");