From 027e7e1578d3d7614f7586eff3894b83d9709e14 Mon Sep 17 00:00:00 2001
From: Hitendra Prajapati <hprajapati@mvista.com>
Date: Mon, 29 Aug 2022 10:08:34 +0530
Subject: [PATCH] CVE-2022-32189

Upstream-Status: Backport [https://github.com/golang/go/commit/703c8ab7e5ba75c95553d4e249309297abad7102]
CVE: CVE-2022-32189
Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
---
 src/math/big/floatmarsh.go      |  7 +++++++
 src/math/big/floatmarsh_test.go | 12 ++++++++++++
 src/math/big/ratmarsh.go        |  6 ++++++
 src/math/big/ratmarsh_test.go   | 12 ++++++++++++
 4 files changed, 37 insertions(+)

diff --git a/src/math/big/floatmarsh.go b/src/math/big/floatmarsh.go
index d1c1dab..990e085 100644
--- a/src/math/big/floatmarsh.go
+++ b/src/math/big/floatmarsh.go
@@ -8,6 +8,7 @@ package big
 
 import (
 	"encoding/binary"
+	"errors"
 	"fmt"
 )
 
@@ -67,6 +68,9 @@ func (z *Float) GobDecode(buf []byte) error {
 		*z = Float{}
 		return nil
 	}
+	if len(buf) < 6 {
+		return errors.New("Float.GobDecode: buffer too small")
+	}
 
 	if buf[0] != floatGobVersion {
 		return fmt.Errorf("Float.GobDecode: encoding version %d not supported", buf[0])
@@ -83,6 +87,9 @@ func (z *Float) GobDecode(buf []byte) error {
 	z.prec = binary.BigEndian.Uint32(buf[2:])
 
 	if z.form == finite {
+		if len(buf) < 10 {
+			return errors.New("Float.GobDecode: buffer too small for finite form float")
+		}
 		z.exp = int32(binary.BigEndian.Uint32(buf[6:]))
 		z.mant = z.mant.setBytes(buf[10:])
 	}
diff --git a/src/math/big/floatmarsh_test.go b/src/math/big/floatmarsh_test.go
index c056d78..401f45a 100644
--- a/src/math/big/floatmarsh_test.go
+++ b/src/math/big/floatmarsh_test.go
@@ -137,3 +137,15 @@ func TestFloatJSONEncoding(t *testing.T) {
 		}
 	}
 }
+
+func TestFloatGobDecodeShortBuffer(t *testing.T) {
+	for _, tc := range [][]byte{
+		[]byte{0x1, 0x0, 0x0, 0x0},
+		[]byte{0x1, 0xfa, 0x0, 0x0, 0x0, 0x0},
+	} {
+		err := NewFloat(0).GobDecode(tc)
+		if err == nil {
+			t.Error("expected GobDecode to return error for malformed input")
+		}
+	}
+}
diff --git a/src/math/big/ratmarsh.go b/src/math/big/ratmarsh.go
index fbc7b60..56102e8 100644
--- a/src/math/big/ratmarsh.go
+++ b/src/math/big/ratmarsh.go
@@ -45,12 +45,18 @@ func (z *Rat) GobDecode(buf []byte) error {
 		*z = Rat{}
 		return nil
 	}
+	if len(buf) < 5 {
+		return errors.New("Rat.GobDecode: buffer too small")
+	}
 	b := buf[0]
 	if b>>1 != ratGobVersion {
 		return fmt.Errorf("Rat.GobDecode: encoding version %d not supported", b>>1)
 	}
 	const j = 1 + 4
 	i := j + binary.BigEndian.Uint32(buf[j-4:j])
+	if len(buf) < int(i) {
+		return errors.New("Rat.GobDecode: buffer too small")
+	}
 	z.a.neg = b&1 != 0
 	z.a.abs = z.a.abs.setBytes(buf[j:i])
 	z.b.abs = z.b.abs.setBytes(buf[i:])
diff --git a/src/math/big/ratmarsh_test.go b/src/math/big/ratmarsh_test.go
index 351d109..55a9878 100644
--- a/src/math/big/ratmarsh_test.go
+++ b/src/math/big/ratmarsh_test.go
@@ -123,3 +123,15 @@ func TestRatXMLEncoding(t *testing.T) {
 		}
 	}
 }
+
+func TestRatGobDecodeShortBuffer(t *testing.T) {
+	for _, tc := range [][]byte{
+		[]byte{0x2},
+		[]byte{0x2, 0x0, 0x0, 0x0, 0xff},
+	} {
+		err := NewRat(1, 2).GobDecode(tc)
+		if err == nil {
+			t.Error("expected GobDecode to return error for malformed input")
+		}
+	}
+}
-- 
2.25.1