From a2a8981979f83e9a28650d12e0eaa123a83c181e Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Mon, 9 Sep 2019 12:07:03 +0300
Subject: [PATCH] vm: fix not failing PUSHBYTES* on short read

Add some tests also. Fixes #361.
---
 pkg/vm/vm.go      |  3 +++
 pkg/vm/vm_test.go | 16 ++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/pkg/vm/vm.go b/pkg/vm/vm.go
index 216f6ca6c..1fa1fe3c7 100644
--- a/pkg/vm/vm.go
+++ b/pkg/vm/vm.go
@@ -242,6 +242,9 @@ func (v *VM) execute(ctx *Context, op Instruction) {
 
 	if op >= PUSHBYTES1 && op <= PUSHBYTES75 {
 		b := ctx.readBytes(int(op))
+		if b == nil {
+			panic("failed to read instruction parameter")
+		}
 		v.estack.PushVal(b)
 		return
 	}
diff --git a/pkg/vm/vm_test.go b/pkg/vm/vm_test.go
index 5324581e4..a27f53b6a 100644
--- a/pkg/vm/vm_test.go
+++ b/pkg/vm/vm_test.go
@@ -60,6 +60,22 @@ func TestPushBytes1to75(t *testing.T) {
 	}
 }
 
+func TestPushBytesNoParam(t *testing.T) {
+	prog := make([]byte, 1)
+	prog[0] = byte(PUSHBYTES1)
+	vm := load(prog)
+	vm.Run()
+	assert.Equal(t, true, vm.state.HasFlag(faultState))
+}
+
+func TestPushBytesShort(t *testing.T) {
+	prog := make([]byte, 10)
+	prog[0] = byte(PUSHBYTES10) // but only 9 left in the `prog`
+	vm := load(prog)
+	vm.Run()
+	assert.Equal(t, true, vm.state.HasFlag(faultState))
+}
+
 func TestPushm1to16(t *testing.T) {
 	var prog []byte
 	for i := int(PUSHM1); i <= int(PUSH16); i++ {