From d61ae9ded4ebc142fb0edccfee893fa10c233357 Mon Sep 17 00:00:00 2001 From: hopehook Date: Sun, 12 Feb 2023 22:27:35 +0800 Subject: [PATCH] mime/multipart: fix Reader.ReadForm(math.MaxInt64) overflow Because "CopyN" will read one more byte, which will cause us to overflow when calling "Reader.ReadForm(math.MaxInt64)". So we should check if the parameter exceeds "math.MaxInt64" to avoid returning no data. Fixes #58384. Change-Id: I30088ce6468176b21e4a9a0b8b6080f2986dda23 Reviewed-on: https://go-review.googlesource.com/c/go/+/467557 TryBot-Result: Gopher Robot Auto-Submit: Ian Lance Taylor Run-TryBot: hopehook Run-TryBot: Ian Lance Taylor Reviewed-by: Bryan Mills Reviewed-by: Ian Lance Taylor --- src/mime/multipart/formdata.go | 3 +++ src/mime/multipart/formdata_test.go | 31 +++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/src/mime/multipart/formdata.go b/src/mime/multipart/formdata.go index 41bc886d16..e62727dbb1 100644 --- a/src/mime/multipart/formdata.go +++ b/src/mime/multipart/formdata.go @@ -77,6 +77,9 @@ func (r *Reader) readForm(maxMemory int64) (_ *Form, err error) { // unconfigurable 10 MB added on to maxMemory, is unfortunate but difficult to change // within the constraints of the API as documented. maxFileMemoryBytes := maxMemory + if maxFileMemoryBytes == math.MaxInt64 { + maxFileMemoryBytes-- + } maxMemoryBytes := maxMemory + int64(10<<20) if maxMemoryBytes <= 0 { if maxMemory < 0 { diff --git a/src/mime/multipart/formdata_test.go b/src/mime/multipart/formdata_test.go index 8a862be717..9b3f9ec392 100644 --- a/src/mime/multipart/formdata_test.go +++ b/src/mime/multipart/formdata_test.go @@ -55,6 +55,23 @@ func TestReadFormWithNamelessFile(t *testing.T) { } } +// Issue 58384: Handle ReadForm(math.MaxInt64) +func TestReadFormWitFileNameMaxMemoryOverflow(t *testing.T) { + b := strings.NewReader(strings.ReplaceAll(messageWithFileName, "\n", "\r\n")) + r := NewReader(b, boundary) + f, err := r.ReadForm(math.MaxInt64) + if err != nil { + t.Fatalf("ReadForm(MaxInt64): %v", err) + } + defer f.RemoveAll() + + fd := testFile(t, f.File["filea"][0], "filea.txt", fileaContents) + if _, ok := fd.(*os.File); ok { + t.Error("file is *os.File, should not be") + } + fd.Close() +} + // Issue 40430: Handle ReadForm(math.MaxInt64) func TestReadFormMaxMemoryOverflow(t *testing.T) { b := strings.NewReader(strings.ReplaceAll(messageWithTextContentType, "\n", "\r\n")) @@ -66,6 +83,11 @@ func TestReadFormMaxMemoryOverflow(t *testing.T) { if f == nil { t.Fatal("ReadForm(MaxInt64): missing form") } + defer f.RemoveAll() + + if g, e := f.Value["texta"][0], textaValue; g != e { + t.Errorf("texta value = %q, want %q", g, e) + } } func TestReadFormWithTextContentType(t *testing.T) { @@ -122,6 +144,15 @@ Content-Type: text/plain --MyBoundary-- ` +const messageWithFileName = ` +--MyBoundary +Content-Disposition: form-data; name="filea"; filename="filea.txt" +Content-Type: text/plain + +` + fileaContents + ` +--MyBoundary-- +` + const messageWithTextContentType = ` --MyBoundary Content-Disposition: form-data; name="texta" -- 2.48.1