From 50e04779c499d5c329d1863b71ecd7c2b5824f76 Mon Sep 17 00:00:00 2001
From: Eitan Adler <eadler@FreeBSD.org>
Date: Mon, 22 Oct 2012 03:07:05 +0000
Subject: [PATCH] Check the return error of set[e][ug]id. While this can never
 fail in the current version of FreeBSD, this isn't guarenteed by the API.
 Custom security modules, or future implementations of the setuid and setgid
 may fail.

Submitted by:	Erik Cederstrand
Approved by:	cperciva
MFC after:	3 days
---
 libexec/tftpd/tftpd.c      | 5 ++++-
 sbin/ccdconfig/ccdconfig.c | 9 ++++++---
 sbin/restore/tape.c        | 6 +++++-
 usr.bin/lock/lock.c        | 4 +++-
 usr.bin/msgs/msgs.c        | 3 ++-
 usr.bin/wall/wall.c        | 3 ++-
 usr.sbin/edquota/edquota.c | 6 ++++--
 usr.sbin/kgmon/kgmon.c     | 4 +++-
 8 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/libexec/tftpd/tftpd.c b/libexec/tftpd/tftpd.c
index 7363abf3c0e9..a0010b3c5032 100644
--- a/libexec/tftpd/tftpd.c
+++ b/libexec/tftpd/tftpd.c
@@ -371,7 +371,10 @@ main(int argc, char *argv[])
 		}
 		chdir("/");
 		setgroups(1, &nobody->pw_gid);
-		setuid(nobody->pw_uid);
+		if (setuid(nobody->pw_uid) != 0) {
+			tftp_log(LOG_ERR, "setuid failed");
+			exit(1);
+		}
 	}
 
 	len = sizeof(me_sock);
diff --git a/sbin/ccdconfig/ccdconfig.c b/sbin/ccdconfig/ccdconfig.c
index 6324150b0ff7..76867ba8ff07 100644
--- a/sbin/ccdconfig/ccdconfig.c
+++ b/sbin/ccdconfig/ccdconfig.c
@@ -288,13 +288,16 @@ do_all(int action)
 
 	rval = 0;
 	egid = getegid();
-	setegid(getgid());
+	if (setegid(getgid()) != 0)
+		err(1, "setegid failed");
 	if ((f = fopen(ccdconf, "r")) == NULL) {
-		setegid(egid);
+		if (setegid(egid) != 0)
+			err(1, "setegid failed");
 		warn("fopen: %s", ccdconf);
 		return (1);
 	}
-	setegid(egid);
+	if (setegid(egid) != 0)
+		err(1, "setegid failed");
 
 	while (fgets(line, sizeof(line), f) != NULL) {
 		argc = 0;
diff --git a/sbin/restore/tape.c b/sbin/restore/tape.c
index f63d573617b7..4f3454901104 100644
--- a/sbin/restore/tape.c
+++ b/sbin/restore/tape.c
@@ -164,7 +164,11 @@ setinput(char *source, int ispipecommand)
 		}
 		pipein++;
 	}
-	setuid(getuid());	/* no longer need or want root privileges */
+	/* no longer need or want root privileges */
+	if (setuid(getuid()) != 0) {
+		fprintf(stderr, "setuid failed\n");
+		done(1);
+	}
 	magtape = strdup(source);
 	if (magtape == NULL) {
 		fprintf(stderr, "Cannot allocate space for magtape buffer\n");
diff --git a/usr.bin/lock/lock.c b/usr.bin/lock/lock.c
index 0382e831862c..acc0e29d62d8 100644
--- a/usr.bin/lock/lock.c
+++ b/usr.bin/lock/lock.c
@@ -129,7 +129,9 @@ main(int argc, char **argv)
 		}
 	timeout.tv_sec = sectimeout * 60;
 
-	setuid(getuid());		/* discard privs */
+	/* discard privs */
+	if (setuid(getuid()) != 0)
+		errx(1, "setuid failed");
 
 	if (tcgetattr(0, &tty))		/* get information for header */
 		exit(1);
diff --git a/usr.bin/msgs/msgs.c b/usr.bin/msgs/msgs.c
index e534fac83da8..c4c589e168e1 100644
--- a/usr.bin/msgs/msgs.c
+++ b/usr.bin/msgs/msgs.c
@@ -175,7 +175,8 @@ main(int argc, char *argv[])
 	setlocale(LC_ALL, "");
 
 	time(&t);
-	setuid(uid = getuid());
+	if (setuid(uid = getuid()) != 0)
+		err(1, "setuid failed");
 	ruptible = (signal(SIGINT, SIG_IGN) == SIG_DFL);
 	if (ruptible)
 		signal(SIGINT, SIG_DFL);
diff --git a/usr.bin/wall/wall.c b/usr.bin/wall/wall.c
index dafd44800f91..b3a63dcbf20a 100644
--- a/usr.bin/wall/wall.c
+++ b/usr.bin/wall/wall.c
@@ -240,7 +240,8 @@ makemsg(char *fname)
 		setegid(getgid());
 		if (freopen(fname, "r", stdin) == NULL)
 			err(1, "can't read %s", fname);
-		setegid(egid);
+		if (setegid(egid) != 0)
+			err(1, "setegid failed");
 	}
 	cnt = 0;
 	while (fgetws(lbuf, sizeof(lbuf)/sizeof(wchar_t), stdin)) {
diff --git a/usr.sbin/edquota/edquota.c b/usr.sbin/edquota/edquota.c
index 0957011b5be4..930a460a3df7 100644
--- a/usr.sbin/edquota/edquota.c
+++ b/usr.sbin/edquota/edquota.c
@@ -453,8 +453,10 @@ editit(char *tmpf)
 		const char *ed;
 
 		sigsetmask(omask);
-		setgid(getgid());
-		setuid(getuid());
+		if (setgid(getgid()) != 0)
+			err(1, "setgid failed");
+		if (setuid(getuid()) != 0)
+			err(1, "setuid failed");
 		if ((ed = getenv("EDITOR")) == (char *)0)
 			ed = _PATH_VI;
 		execlp(ed, ed, tmpf, (char *)0);
diff --git a/usr.sbin/kgmon/kgmon.c b/usr.sbin/kgmon/kgmon.c
index d5cdf961768b..c691d6ecf414 100644
--- a/usr.sbin/kgmon/kgmon.c
+++ b/usr.sbin/kgmon/kgmon.c
@@ -90,7 +90,9 @@ main(int argc, char **argv)
 	struct kvmvars kvmvars;
 	char *system, *kmemf;
 
-	seteuid(getuid());
+	if (seteuid(getuid()) != 0) {
+		err(1, "seteuid failed\n");
+	}
 	kmemf = NULL;
 	system = NULL;
 	while ((ch = getopt(argc, argv, "M:N:Bbhpr")) != -1) {