From 703c8ab7e5ba75c95553d4e249309297abad7102 Mon Sep 17 00:00:00 2001 From: Roland Shoemaker Date: Fri, 15 Jul 2022 10:43:44 -0700 Subject: [release-branch.go1.17] math/big: check buffer lengths in GobDecode In Float.GobDecode and Rat.GobDecode, check buffer sizes before indexing slices. Updates #53871 Fixes #54094 Change-Id: I1b652c32c2bc7a0e8aa7620f7be9b2740c568b0a Reviewed-on: https://go-review.googlesource.com/c/go/+/417774 TryBot-Result: Gopher Robot Reviewed-by: Tatiana Bradley Run-TryBot: Roland Shoemaker (cherry picked from commit 055113ef364337607e3e72ed7d48df67fde6fc66) Reviewed-on: https://go-review.googlesource.com/c/go/+/419814 Reviewed-by: Julie Qiu --- src/math/big/floatmarsh.go | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'src/math/big/floatmarsh.go') diff --git a/src/math/big/floatmarsh.go b/src/math/big/floatmarsh.go index d1c1dab069..990e085abe 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:]) } -- cgit v1.2.3-54-g00ecf