From 0732075869fa971a0c70b94bcc751a02963cfbe8 Mon Sep 17 00:00:00 2001
From: Sean Cross <sean@xobs.io>
Date: Mon, 23 Nov 2020 19:31:52 +0800
Subject: [PATCH] graphics-server: bounds-check the circle drawing

Otherwise we could overflow the buffer.

Signed-off-by: Sean Cross <sean@xobs.io>
---
 services/graphics-server/src/op.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/services/graphics-server/src/op.rs b/services/graphics-server/src/op.rs
index 497b38f0b..dea595578 100644
--- a/services/graphics-server/src/op.rs
+++ b/services/graphics-server/src/op.rs
@@ -280,6 +280,9 @@ fn line_fill_padded_border(fb: &mut LcdFB, y: usize) {
 }
 
 fn put_pixel(fb: &mut LcdFB, x: usize, y: usize, color: PixelColor) {
+    if (x >= LCD_PX_PER_LINE) || (y >= LCD_LINES) {
+        return;
+    }
     if color == PixelColor::Off {
         fb[(x + y * LCD_WORDS_PER_LINE * 32) / 32] |= 1 << (x % 32)
     } else {