From 96fd50be10885c9b3033404df698177fdb63d036 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Mon, 1 Oct 2018 14:17:37 +0200
Subject: [PATCH] accounts/abi: fix panic in MethodById lookup. Fixes #17797
(#17798)
---
accounts/abi/abi.go | 3 +++
accounts/abi/abi_test.go | 11 ++++++++++-
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/accounts/abi/abi.go b/accounts/abi/abi.go
index 254b1f7fb..535e5d78b 100644
--- a/accounts/abi/abi.go
+++ b/accounts/abi/abi.go
@@ -137,6 +137,9 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
// MethodById looks up a method by the 4-byte id
// returns nil if none found
func (abi *ABI) MethodById(sigdata []byte) (*Method, error) {
+ if len(sigdata) < 4 {
+ return nil, fmt.Errorf("data too short (% bytes) for abi method lookup", len(sigdata))
+ }
for _, method := range abi.Methods {
if bytes.Equal(method.Id(), sigdata[:4]) {
return &method, nil
diff --git a/accounts/abi/abi_test.go b/accounts/abi/abi_test.go
index 8018df775..59ba79cb6 100644
--- a/accounts/abi/abi_test.go
+++ b/accounts/abi/abi_test.go
@@ -711,5 +711,14 @@ func TestABI_MethodById(t *testing.T) {
t.Errorf("Method %v (id %v) not 'findable' by id in ABI", name, common.ToHex(m.Id()))
}
}
-
+ // Also test empty
+ if _, err := abi.MethodById([]byte{0x00}); err == nil {
+ t.Errorf("Expected error, too short to decode data")
+ }
+ if _, err := abi.MethodById([]byte{}); err == nil {
+ t.Errorf("Expected error, too short to decode data")
+ }
+ if _, err := abi.MethodById(nil); err == nil {
+ t.Errorf("Expected error, nil is short to decode data")
+ }
}
--
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