From 5246fa5e75b129a7dbd9722aa4de0cbaf7ceae43 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Thu, 3 Dec 2020 09:45:07 -0500 Subject: [PATCH] mime/multipart: handle ReadForm(math.MaxInt64) better Returning an error about integer overflow is needlessly pedantic. The meaning of ReadForm(MaxInt64) is easily understood (accept a lot of data) and can be implemented. Fixes #40430. Change-Id: I8a522033dd9a2f9ad31dd2ad82cf08d553736ab9 Reviewed-on: https://go-review.googlesource.com/c/go/+/275112 Trust: Russ Cox Run-TryBot: Russ Cox TryBot-Result: Go Bot Reviewed-by: Ian Lance Taylor Upstream-Status: Backport [https://github.com/golang/go/commit/5246fa5e75b129a7dbd9722aa4de0cbaf7ceae43] CVE: CVE-2022-41725 #Dependency Patch3 Signed-off-by: Vijay Anusuri --- src/mime/multipart/formdata.go | 8 ++++++-- src/mime/multipart/formdata_test.go | 14 +++++--------- src/net/http/request_test.go | 2 +- 3 files changed, 12 insertions(+), 12 deletions(-) diff --git a/src/mime/multipart/formdata.go b/src/mime/multipart/formdata.go index 4eb31012941ac..9c42ea8c023b5 100644 --- a/src/mime/multipart/formdata.go +++ b/src/mime/multipart/formdata.go @@ -7,9 +7,9 @@ package multipart import ( "bytes" "errors" - "fmt" "io" "io/ioutil" + "math" "net/textproto" "os" ) @@ -43,7 +43,11 @@ func (r *Reader) readForm(maxMemory int64) (_ *Form, err error) { // Reserve an additional 10 MB for non-file parts. maxValueBytes := maxMemory + int64(10<<20) if maxValueBytes <= 0 { - return nil, fmt.Errorf("multipart: integer overflow from maxMemory(%d) + 10MiB for non-file parts", maxMemory) + if maxMemory < 0 { + maxValueBytes = 0 + } else { + maxValueBytes = math.MaxInt64 + } } for { p, err := r.NextPart() diff --git a/src/mime/multipart/formdata_test.go b/src/mime/multipart/formdata_test.go index 7112e0d3727fe..e3a3a3eae8e15 100644 --- a/src/mime/multipart/formdata_test.go +++ b/src/mime/multipart/formdata_test.go @@ -53,20 +53,16 @@ func TestReadFormWithNamelessFile(t *testing.T) { } } -// Issue 40430: Ensure that we report integer overflows in additions of maxMemory, -// instead of silently and subtly failing without indication. +// Issue 40430: Handle ReadForm(math.MaxInt64) func TestReadFormMaxMemoryOverflow(t *testing.T) { b := strings.NewReader(strings.ReplaceAll(messageWithTextContentType, "\n", "\r\n")) r := NewReader(b, boundary) f, err := r.ReadForm(math.MaxInt64) - if err == nil { - t.Fatal("Unexpected a non-nil error") - } - if f != nil { - t.Fatalf("Unexpected returned a non-nil form: %v\n", f) + if err != nil { + t.Fatalf("ReadForm(MaxInt64): %v", err) } - if g, w := err.Error(), "integer overflow from maxMemory"; !strings.Contains(g, w) { - t.Errorf(`Error mismatch\n%q\ndid not contain\n%q`, g, w) + if f == nil { + t.Fatal("ReadForm(MaxInt64): missing form") } } diff --git a/src/net/http/request_test.go b/src/net/http/request_test.go index 19526b9ad791a..689498e19d5dd 100644 --- a/src/net/http/request_test.go +++ b/src/net/http/request_test.go @@ -285,7 +285,7 @@ func TestMaxInt64ForMultipartFormMaxMemoryOverflow(t *testing.T) { t.Fatal(err) } res.Body.Close() - if g, w := res.StatusCode, StatusBadRequest; g != w { + if g, w := res.StatusCode, StatusOK; g != w { t.Fatalf("Status code mismatch: got %d, want %d", g, w) } }