From 659cb59cd6cfe36c954c77f945c06a0cd8218287 Mon Sep 17 00:00:00 2001
From: Petr Lautrbach <plautrba@redhat.com>
Date: Mon, 15 Apr 2019 15:22:51 +0200
Subject: [PATCH] mcstrans: Do not accept incomplete contexts
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fixes:
$ python3
> import selinux
> selinux.selinux_raw_context_to_color("xyz_u:xyz_r:xyz_t:")

Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
OSError: [Errno 0] Error

:: [ 10:25:45 ] :: [  BEGIN   ] :: Running 'service mcstransd status'
Redirecting to /bin/systemctl status mcstransd.service
● mcstrans.service - Translates SELinux MCS/MLS labels to human readable form
   Loaded: loaded (/usr/lib/systemd/system/mcstrans.service; disabled; vendor preset: disabled)
   Active: failed (Result: core-dump) since Fri 2019-04-12 10:25:44 EDT; 1s ago
  Process: 16681 ExecStart=/sbin/mcstransd -f (code=dumped, signal=SEGV)
 Main PID: 16681 (code=dumped, signal=SEGV)

systemd[1]: mcstrans.service: Main process exited, code=dumped, status=11/SEGV
systemd[1]: mcstrans.service: Failed with result 'core-dump'.

Signed-off-by: Petr Lautrbach <plautrba@redhat.com>
---
 mcstrans/src/mcscolor.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/mcstrans/src/mcscolor.c b/mcstrans/src/mcscolor.c
index 6ea1aa97..79fc1c8b 100644
--- a/mcstrans/src/mcscolor.c
+++ b/mcstrans/src/mcscolor.c
@@ -272,10 +272,14 @@ static const unsigned precedence[N_COLOR][N_COLOR - 1] = {
 static const secolor_t default_color = { 0x000000, 0xffffff };
 
 static int parse_components(context_t con, char **components) {
-	components[COLOR_USER] = (char *)context_user_get(con);
-	components[COLOR_ROLE] = (char *)context_role_get(con);
-	components[COLOR_TYPE] = (char *)context_type_get(con);
-	components[COLOR_RANGE] = (char *)context_range_get(con);
+	if ((components[COLOR_USER] = (char *)context_user_get(con)) == NULL)
+		return -1;
+	if ((components[COLOR_ROLE] = (char *)context_role_get(con)) == NULL)
+		return -1;
+	if ((components[COLOR_TYPE] = (char *)context_type_get(con)) == NULL)
+		return -1;
+	if ((components[COLOR_RANGE] = (char *)context_range_get(con)) == NULL)
+		return -1;
 
 	return 0;
 }
-- 
2.21.0