diff --git a/scstadmin/scstadmin.sysfs/scst-1.0.0/lib/SCST/SCST.pm b/scstadmin/scstadmin.sysfs/scst-1.0.0/lib/SCST/SCST.pm
index f8a05928c..9f69ba3f4 100644
--- a/scstadmin/scstadmin.sysfs/scst-1.0.0/lib/SCST/SCST.pm
+++ b/scstadmin/scstadmin.sysfs/scst-1.0.0/lib/SCST/SCST.pm
@@ -359,7 +359,11 @@ sub readOnly {
 	my ($path) = @_;
 	my $mode = (stat($path))[2];
 
-	return ($mode & S_IWUSR) != 0;
+	if (!defined($mode)) {
+		cluck("invalid path $path");
+		return undef;
+	}
+	return ($mode & S_IWUSR) == 0;
 }
 
 sub scstVersion {
@@ -488,15 +492,16 @@ sub setScstAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	return TRUE if (!length($attribute) || !length($value));
+	return TRUE if (!length($attribute) || !defined($value));
 
-	my $bytes = - ENOENT;
+	my $bytes = -ENOENT;
 	my $path = make_path(SCST_ROOT_DIR(), $attribute);
 	my $io = new IO::File $path, O_WRONLY;
 	if ($io) {
 		if ($self->{'debug'}) {
 			print "DBG($$): $path -> $attribute = $value\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -2583,7 +2588,7 @@ sub setDriverAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	return TRUE if (!length($attribute) || !length($value));
+	return TRUE if (!length($attribute) || !defined($value));
 
 	my $path = make_path(SCST_TARGETS_DIR(), $driver, $attribute);
 
@@ -2593,6 +2598,7 @@ sub setDriverAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $path -> $attribute = $value\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -2720,7 +2726,7 @@ sub setTargetAttribute {
 	my $value = shift;
 
 	return TRUE if (!length($driver) || !length($target) ||
-			!length($attribute) || !length($value));
+			!length($attribute) || !defined($value));
 
 	my ($path, $cmd);
 	$path = make_path(SCST_TARGETS_DIR(), $driver, $target, $attribute);
@@ -2846,7 +2852,7 @@ sub setGroupAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	return TRUE if (!length($attribute) || !length($value));
+	return TRUE if (!length($attribute) || !defined($value));
 
 	my ($path, $cmd);
 	$path = make_path(SCST_TARGETS_DIR(), $driver, $target, SCST_GROUPS,
@@ -2859,6 +2865,7 @@ sub setGroupAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $cmd > $path\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -2998,7 +3005,7 @@ sub setLunAttribute {
 
 	return SCST_C_LUN_SETATTR_FAIL
 	    if (!length($driver) || !length($target) || !length($lun) ||
-		!length($attribute) || !length($value));
+		!length($attribute) || !defined($value));
 
 	my $path;
 
@@ -3017,6 +3024,7 @@ sub setLunAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $path -> $attribute = $value\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -3148,7 +3156,7 @@ sub setInitiatorAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	return TRUE if (!length($attribute) || !length($value));
+	return TRUE if (!length($attribute) || !defined($value));
 
 	my $path = make_path(SCST_TARGETS_DIR(), $driver, $target, SCST_GROUPS,
 			     $group, SCST_LUNS, $initiator, $attribute);
@@ -3159,6 +3167,7 @@ sub setInitiatorAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $path -> $attribute = $value\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -3435,7 +3444,7 @@ sub setAluaAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	return TRUE if (!length($attribute) || !length($value));
+	return TRUE if (!length($attribute) || !defined($value));
 
 	my $bytes = - ENOENT;
 	my $path = make_path(SCST_DEV_GROUP_DIR(), $attribute);
@@ -3444,6 +3453,7 @@ sub setAluaAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $value > $path\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -3461,7 +3471,7 @@ sub setDeviceGroupAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	return TRUE if (!length($attribute) || !length($value));
+	return TRUE if (!length($attribute) || !defined($value));
 
 	my $bytes = - ENOENT;
 	my $path = make_path(SCST_DEV_GROUP_DIR(), $group, $attribute);
@@ -3470,6 +3480,7 @@ sub setDeviceGroupAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $path -> $attribute = $value\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -3493,7 +3504,7 @@ sub setTargetGroupAttribute {
 	my $value = shift;
 
 	return TRUE if (!length($group) || !length($tgroup) ||
-			!length($attribute) || !length($value));
+			!length($attribute) || !defined($value));
 
 	my $bytes = - ENOENT;
 	my $path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS, $tgroup, $attribute);
@@ -3502,6 +3513,7 @@ sub setTargetGroupAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $path -> $attribute = $value\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -3531,7 +3543,7 @@ sub setTargetGroupTargetAttribute {
 
 	return TRUE if (!length($group) || !length($tgroup) ||
 			!length($tgt) || !length($attribute) ||
-			!length($value));
+			!defined($value));
 
 	my $bytes = - ENOENT;
 	my $path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS,
@@ -3541,6 +3553,7 @@ sub setTargetGroupTargetAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $path -> $attribute = $value\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -3612,7 +3625,7 @@ sub setHandlerAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	return TRUE if (!length($attribute) || !length($value));
+	return TRUE if (!length($attribute) || !defined($value));
 
 	my $bytes = - ENOENT;
 	my $path = make_path(SCST_HANDLERS_DIR(), $handler, $attribute);
@@ -3621,6 +3634,7 @@ sub setHandlerAttribute {
 		if ($self->{'debug'}) {
 			print "DBG($$): $path -> $attribute = $value\n";
 		} else {
+			$value .= "\n";
 			$bytes = _syswrite($io, $value, length($value));
 		}
 		close $io;
@@ -4618,6 +4632,7 @@ sub make_path {
 		if ($path && rindex($path, '/') != length($path) - 1) {
 			$path .= '/';
 		}
+		cluck("make_path: invalid argument") if !length($element);
 		$path .= $element;
 	}
 
diff --git a/scstadmin/scstadmin.sysfs/scst-1.0.0/t/02-scst-attr.t b/scstadmin/scstadmin.sysfs/scst-1.0.0/t/02-scst-attr.t
index 0bd7c9801..52321f5b9 100644
--- a/scstadmin/scstadmin.sysfs/scst-1.0.0/t/02-scst-attr.t
+++ b/scstadmin/scstadmin.sysfs/scst-1.0.0/t/02-scst-attr.t
@@ -5,7 +5,7 @@ use warnings;
 use Test;
 
 BEGIN {
-    plan tests => 6 + ($> == 0 ? 4 : 0);
+    plan tests => 7 + ($> == 0 ? 8 : 0);
 }
 
 use SCST::SCST;
@@ -22,20 +22,29 @@ my $_DEBUG_ = 0;
 my $SCST = eval { new SCST::SCST($_DEBUG_) };
 die("Creation of SCST object failed") if (!defined($SCST));
 
+# Missing `attribute` and `value` arguments.
 ok($SCST->setScstAttribute(), 1);
 
+# `attribute` argument is an empty string.
+ok($SCST->setScstAttribute(''), 1);
+
+# `attribute` argument is not an existing attribute and the `value` argument is
+# missing.
 ok($SCST->setScstAttribute('no-such-attribute'), 1);
 
+# `attribute` argument is not an existing attribute.
 ok($SCST->setScstAttribute('no-such-attribute', '1'),
    $SCST->SCST_C_BAD_ATTRIBUTES);
 
+# Attempt to modify a read-only attribute.
 ok($SCST->setScstAttribute('last_sysfs_mgmt_res', '1'),
-   $SCST->SCST_C_SETATTR_FAIL);
+   $SCST->SCST_C_ATTRIBUTE_STATIC);
 
 my $threads = getScstThreadCount($SCST);
 ok(ref(\$threads), "SCALAR");
 ok(defined($threads));
 
+# $> represents the effective user ID of this process.
 if ($> == 0) {
     ok($SCST->setScstAttribute('threads', $threads + 1), 0);
 
@@ -44,4 +53,14 @@ if ($> == 0) {
     ok($SCST->setScstAttribute('threads', $threads), 0);
 
     ok(getScstThreadCount($SCST), $threads);
+
+    ok($SCST->setScstAttribute('measure_latency', undef), 1);
+
+    ok($SCST->setScstAttribute('measure_latency', ""),
+       $SCST->SCST_C_SETATTR_FAIL);
+
+    ok($SCST->setScstAttribute('measure_latency', "."),
+       $SCST->SCST_C_SETATTR_FAIL);
+
+    ok($SCST->setScstAttribute('measure_latency', "0"), 0);
 }