From 65b65c54baa9fcc36298f06a7bca808b2ac967e7 Mon Sep 17 00:00:00 2001
From: Connor Brewster <cbrewster@mozilla.com>
Date: Wed, 10 Jul 2019 22:37:44 +0000
Subject: [PATCH] Bug 1555483 - Part 4: Sanitize filter primitives r=gw

Differential Revision: https://phabricator.services.mozilla.com/D35741

--HG--
extra : moz-landing-system : lando
---
 .../webrender/src/display_list_flattener.rs   |  5 ++
 gfx/wr/webrender_api/src/display_item.rs      | 51 +++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/gfx/wr/webrender/src/display_list_flattener.rs b/gfx/wr/webrender/src/display_list_flattener.rs
index 4af0018de746..43f099454b64 100644
--- a/gfx/wr/webrender/src/display_list_flattener.rs
+++ b/gfx/wr/webrender/src/display_list_flattener.rs
@@ -1998,6 +1998,11 @@ impl<'a> DisplayListFlattener<'a> {
                 })
                 .collect();
 
+            // Sanitize filter inputs
+            for primitive in &mut stacking_context.composite_ops.filter_primitives {
+                primitive.sanitize();
+            }
+
             let composite_mode = PictureCompositeMode::SvgFilter(
                 stacking_context.composite_ops.filter_primitives,
                 filter_datas,
diff --git a/gfx/wr/webrender_api/src/display_item.rs b/gfx/wr/webrender_api/src/display_item.rs
index dd2465bb5f7d..8c820c152bf2 100644
--- a/gfx/wr/webrender_api/src/display_item.rs
+++ b/gfx/wr/webrender_api/src/display_item.rs
@@ -744,6 +744,15 @@ pub struct FloodPrimitive {
     pub color: ColorF,
 }
 
+impl FloodPrimitive {
+    pub fn sanitize(&mut self) {
+        self.color.r = self.color.r.min(1.0).max(0.0);
+        self.color.g = self.color.g.min(1.0).max(0.0);
+        self.color.b = self.color.b.min(1.0).max(0.0);
+        self.color.a = self.color.a.min(1.0).max(0.0);
+    }
+}
+
 #[repr(C)]
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
 pub struct BlurPrimitive {
@@ -751,6 +760,12 @@ pub struct BlurPrimitive {
     pub radius: f32,
 }
 
+impl BlurPrimitive {
+    pub fn sanitize(&mut self) {
+        self.radius = self.radius.min(MAX_BLUR_RADIUS);
+    }
+}
+
 #[repr(C)]
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
 pub struct OpacityPrimitive {
@@ -758,6 +773,12 @@ pub struct OpacityPrimitive {
     pub opacity: f32,
 }
 
+impl OpacityPrimitive {
+    pub fn sanitize(&mut self) {
+        self.opacity = self.opacity.min(1.0).max(0.0);
+    }
+}
+
 /// cbindgen:derive-eq=false
 #[repr(C)]
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
@@ -773,6 +794,12 @@ pub struct DropShadowPrimitive {
     pub shadow: Shadow,
 }
 
+impl DropShadowPrimitive {
+    pub fn sanitize(&mut self) {
+        self.shadow.blur_radius = self.shadow.blur_radius.min(MAX_BLUR_RADIUS);
+    }
+}
+
 #[repr(C)]
 #[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
 pub struct ComponentTransferPrimitive {
@@ -803,6 +830,24 @@ pub enum FilterPrimitiveKind {
     ComponentTransfer(ComponentTransferPrimitive),
 }
 
+impl FilterPrimitiveKind {
+    pub fn sanitize(&mut self) {
+        match self {
+            FilterPrimitiveKind::Flood(flood) => flood.sanitize(),
+            FilterPrimitiveKind::Blur(blur) => blur.sanitize(),
+            FilterPrimitiveKind::Opacity(opacity) => opacity.sanitize(),
+            FilterPrimitiveKind::DropShadow(drop_shadow) => drop_shadow.sanitize(),
+
+            // No sanitization needed.
+            FilterPrimitiveKind::Identity(..) |
+            FilterPrimitiveKind::Blend(..) |
+            FilterPrimitiveKind::ColorMatrix(..) |
+            // Component transfer's filter data is sanitized separately.
+            FilterPrimitiveKind::ComponentTransfer(..) => {}
+        }
+    }
+}
+
 /// SVG Filter Primitive.
 /// See: https://github.com/eqrion/cbindgen/issues/9
 /// cbindgen:derive-eq=false
@@ -813,6 +858,12 @@ pub struct FilterPrimitive {
     pub color_space: ColorSpace,
 }
 
+impl FilterPrimitive {
+    pub fn sanitize(&mut self) {
+        self.kind.sanitize();
+    }
+}
+
 /// CSS filter.
 #[repr(C)]
 #[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]