fix(notify): cap image dimensions and rank icon_data last

A notification is untrusted input. RawImage.PNG computed
stride*(Height-1)+Width*Channels in int, so Width=Height=2^31-1 with
RowStride=0 wrapped the length expression negative, slipped past the
guard, and reached image.NewRGBA, which panics. The D-Bus call path has
no recover, so one malformed Notify killed the daemon. Cap Width/Height
at 1<<16 before any multiplication and compute the required byte count
in int64.

image-data, image-path and the deprecated icon_data were read as one
tier, with icon_data ahead of image-path, inverting the spec's order.
Split the deprecated key into IconDataFromHints and apply tier 1
(image-data/image_data), then image-path, then icon_data. Raw handling
is unchanged: encode, hold pendingImage, WriteImage after Add, SetImage.

1 files changed, 40 insertions, 0 deletions

diff --git a/internal/notify/service_test.go b/internal/notify/service_test.go
index 3d7c2cc..f7d7195 100644
--- a/internal/notify/service_test.go
+++ b/internal/notify/service_test.go
@@ -133,6 +133,46 @@ func TestNotifyMaterialisesImageData(t *testing.T) {
 	}
 }
 
+// The deprecated icon_data must lose to the image-path URI it outranked when
+// the keys were read in one tier.
+func TestNotifyIconDataDoesNotBeatImagePath(t *testing.T) {
+	var live []Popup
+	s := &Service{dir: t.TempDir(), timers: map[uint32]*time.Timer{}}
+	s.store = NewStore(s.emitClosed, func(l, _ []Popup) { live = l }, s.removeImage)
+	rgba := []byte{255, 0, 0, 255, 0, 255, 0, 255}
+	hints := map[string]dbus.Variant{
+		"icon_data":  dbus.MakeVariant([]interface{}{int32(2), int32(1), int32(8), true, int32(8), int32(4), rgba}),
+		"image-path": dbus.MakeVariant("/tmp/shot.png"),
+	}
+	if _, dbusErr := s.Notify("t", 0, "", "s", "b", nil, hints, -1); dbusErr != nil {
+		t.Fatal(dbusErr)
+	}
+	if len(live) != 1 || live[0].Image != "/tmp/shot.png" {
+		t.Fatalf("published %+v, want image-path", live)
+	}
+}
+
+// image-data is tier 1, above both image-path and icon_data.
+func TestNotifyImageDataBeatsIconDataAndPath(t *testing.T) {
+	var live []Popup
+	s := &Service{dir: t.TempDir(), timers: map[uint32]*time.Timer{}}
+	s.store = NewStore(s.emitClosed, func(l, _ []Popup) { live = l }, s.removeImage)
+	rgba := []byte{255, 0, 0, 255, 0, 255, 0, 255}
+	hints := map[string]dbus.Variant{
+		"image-data": dbus.MakeVariant([]interface{}{int32(2), int32(1), int32(8), true, int32(8), int32(4), rgba}),
+		"icon_data":  dbus.MakeVariant([]interface{}{int32(9), int32(1), int32(8), true, int32(8), int32(4), rgba}),
+		"image-path": dbus.MakeVariant("/tmp/shot.png"),
+	}
+	id, dbusErr := s.Notify("t", 0, "", "s", "b", nil, hints, -1)
+	if dbusErr != nil {
+		t.Fatal(dbusErr)
+	}
+	want := filepath.Join(ImagesDir(s.dir), strconv.FormatUint(uint64(id), 10)+".png")
+	if len(live) != 1 || live[0].Image != want {
+		t.Fatalf("published %+v, want image-data %q", live, want)
+	}
+}
+
 func TestNotifyReturnsAnIDAndPublishes(t *testing.T) {
 	conn := busOrSkip(t)
 	dir := t.TempDir()