From 72c8a04558383dfe4bae383db0e3c33ced84fd26 Mon Sep 17 00:00:00 2001
From: Alessio Treglia <alessio@tendermint.com>
Date: Fri, 7 Feb 2020 19:09:19 +0100
Subject: [PATCH] Merge PR #5620: Fix nil pointer deref in distribution
 tax/rewward validation helpers

---
 CHANGELOG.md                        |  1 +
 x/distribution/types/params.go      |  9 ++++++++
 x/distribution/types/params_test.go | 34 +++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)
 create mode 100644 x/distribution/types/params_test.go

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9af4693d4ef4..a2a5de776a4c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -43,6 +43,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 * (client) [\#5618](https://github.com/cosmos/cosmos-sdk/pull/5618) Fix crash on the client when the verifier is not set.
 * (crypto/keys/mintkey) [\#5823](https://github.com/cosmos/cosmos-sdk/pull/5823) fix errors handling in UnarmorPubKeyBytes (underlying armoring function's return error was not being checked).
+* (x/distribution) [\#5620](https://github.com/cosmos/cosmos-sdk/pull/5620) Fix nil pointer deref in distribution tax/rewward validation helpers.
 
 ### Improvements
 
diff --git a/x/distribution/types/params.go b/x/distribution/types/params.go
index ac3387e9c48b..f4530dd81c3b 100644
--- a/x/distribution/types/params.go
+++ b/x/distribution/types/params.go
@@ -92,6 +92,9 @@ func validateCommunityTax(i interface{}) error {
 		return fmt.Errorf("invalid parameter type: %T", i)
 	}
 
+	if v.IsNil() {
+		return fmt.Errorf("community tax must be not nil")
+	}
 	if v.IsNegative() {
 		return fmt.Errorf("community tax must be positive: %s", v)
 	}
@@ -108,6 +111,9 @@ func validateBaseProposerReward(i interface{}) error {
 		return fmt.Errorf("invalid parameter type: %T", i)
 	}
 
+	if v.IsNil() {
+		return fmt.Errorf("base proposer reward must be not nil")
+	}
 	if v.IsNegative() {
 		return fmt.Errorf("base proposer reward must be positive: %s", v)
 	}
@@ -124,6 +130,9 @@ func validateBonusProposerReward(i interface{}) error {
 		return fmt.Errorf("invalid parameter type: %T", i)
 	}
 
+	if v.IsNil() {
+		return fmt.Errorf("bonus proposer reward must be not nil")
+	}
 	if v.IsNegative() {
 		return fmt.Errorf("bonus proposer reward must be positive: %s", v)
 	}
diff --git a/x/distribution/types/params_test.go b/x/distribution/types/params_test.go
new file mode 100644
index 000000000000..143e2d30d77d
--- /dev/null
+++ b/x/distribution/types/params_test.go
@@ -0,0 +1,34 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+func Test_validateAuxFuncs(t *testing.T) {
+	type args struct {
+		i interface{}
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{"wrong type", args{10.5}, true},
+		{"nil Int pointer", args{sdk.Dec{}}, true},
+		{"negative", args{sdk.NewDec(-1)}, true},
+		{"one dec", args{sdk.NewDec(1)}, false},
+		{"two dec", args{sdk.NewDec(2)}, true},
+	}
+	for _, tt := range tests {
+		tt = tt
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.wantErr, validateCommunityTax(tt.args.i) != nil)
+			require.Equal(t, tt.wantErr, validateBaseProposerReward(tt.args.i) != nil)
+			require.Equal(t, tt.wantErr, validateBonusProposerReward(tt.args.i) != nil)
+		})
+	}
+}