From dad99db2479456735d8e38ca7cd7bd40b1b23c03 Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Tue, 27 Dec 2016 17:13:31 +0000
Subject: [PATCH] Add MAX_LUNS overflow safety checks.

While this MAX_LUNS limitation is too synthetic and should be removed,
it is better to enforce it while it is here.

MFC after:	2 weeks
---
 usr.sbin/ctld/parse.y    | 10 ++++++++++
 usr.sbin/ctld/uclparse.c | 21 +++++++++++++++++----
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/usr.sbin/ctld/parse.y b/usr.sbin/ctld/parse.y
index 820b4c7d4bc1..dc7ff711debf 100644
--- a/usr.sbin/ctld/parse.y
+++ b/usr.sbin/ctld/parse.y
@@ -821,6 +821,11 @@ lun_number:	STR
 			free($1);
 			return (1);
 		}
+		if (tmp >= MAX_LUNS) {
+			yyerror("LU number is too big");
+			free($1);
+			return (1);
+		}
 
 		ret = asprintf(&name, "%s,lun,%ju", target->t_name, tmp);
 		if (ret <= 0)
@@ -845,6 +850,11 @@ target_lun_ref:	LUN STR STR
 			return (1);
 		}
 		free($2);
+		if (tmp >= MAX_LUNS) {
+			yyerror("LU number is too big");
+			free($3);
+			return (1);
+		}
 
 		lun = lun_find(conf, $3);
 		free($3);
diff --git a/usr.sbin/ctld/uclparse.c b/usr.sbin/ctld/uclparse.c
index 3cf95cf81ffa..21872420b62d 100644
--- a/usr.sbin/ctld/uclparse.c
+++ b/usr.sbin/ctld/uclparse.c
@@ -183,18 +183,25 @@ static int
 uclparse_target_lun(struct target *target, const ucl_object_t *obj)
 {
 	struct lun *lun;
+	uint64_t tmp;
 
 	if (obj->type == UCL_INT) {
 		char *name;
 
-		asprintf(&name, "%s,lun,%ju", target->t_name,
-		    ucl_object_toint(obj));
+		tmp = ucl_object_toint(obj);
+		if (tmp >= MAX_LUNS) {
+			log_warnx("LU number %ju in target \"%s\" is too big",
+			    tmp, target->t_name);
+			return (1);
+		}
+
+		asprintf(&name, "%s,lun,%ju", target->t_name, tmp);
 		lun = lun_new(conf, name);
 		if (lun == NULL)
 			return (1);
 
 		lun_set_scsiname(lun, name);
-		target->t_luns[ucl_object_toint(obj)] = lun;
+		target->t_luns[tmp] = lun;
 		return (0);
 	}
 
@@ -207,6 +214,12 @@ uclparse_target_lun(struct target *target, const ucl_object_t *obj)
 			    "\"number\" integer property", target->t_name);
 			return (1);
 		}
+		tmp = ucl_object_toint(num);
+		if (tmp >= MAX_LUNS) {
+			log_warnx("LU number %ju in target \"%s\" is too big",
+			    tmp, target->t_name);
+			return (1);
+		}
 
 		if (name == NULL || name->type != UCL_STRING) {
 			log_warnx("lun section in target \"%s\" is missing "
@@ -218,7 +231,7 @@ uclparse_target_lun(struct target *target, const ucl_object_t *obj)
 		if (lun == NULL)
 			return (1);
 
-		target->t_luns[ucl_object_toint(num)] = lun;
+		target->t_luns[tmp] = lun;
 	}
 
 	return (0);