[Qemu-devel] [PATCH v2] qxl-render: add more sanity checks

[Gerd Hoffmann <kraxel@redhat.com>]

Damn, the dirty rectangle values are signed integers.  So the checks
added by commit 788fbf042fc6d5aaeab56757e6dad622ac5f0c21 are not good
enouth, we also have to make sure they are not negative.

[ Note: There must be something broken in spice-server so we get
  negative values in the first place.  Bug opened:
  https://bugzilla.redhat.com/show_bug.cgi?id=1135372 ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/display/qxl-render.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/display/qxl-render.c b/hw/display/qxl-render.c
index cc2c2b1..bcc5c37 100644
--- a/hw/display/qxl-render.c
+++ b/hw/display/qxl-render.c
@@ -138,7 +138,9 @@ static void qxl_render_update_area_unlocked(PCIQXLDevice *qxl)
         if (qemu_spice_rect_is_empty(qxl->dirty+i)) {
             break;
         }
-        if (qxl->dirty[i].left > qxl->dirty[i].right ||
+        if (qxl->dirty[i].left < 0 ||
+            qxl->dirty[i].top < 0 ||
+            qxl->dirty[i].left > qxl->dirty[i].right ||
             qxl->dirty[i].top > qxl->dirty[i].bottom ||
             qxl->dirty[i].right > qxl->guest_primary.surface.width ||
             qxl->dirty[i].bottom > qxl->guest_primary.surface.height) {
-- 
1.8.3.1