From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Check for zero width/height destination rectangle in
drm_rect_clip_scaled() to avoid a division by zero.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: f96bdf564f3e ("drm/rect: Handle rounding errors in drm_rect_clip_scaled, v3.")
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Benjamin Gaignard <benjamin.gaignard@xxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Testcase: igt/kms_selftest/drm_rect_clip_scaled_div_by_zero
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_rect.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
index b8363aaa9032..818738e83d06 100644
--- a/drivers/gpu/drm/drm_rect.c
+++ b/drivers/gpu/drm/drm_rect.c
@@ -54,7 +54,12 @@ EXPORT_SYMBOL(drm_rect_intersect);
static u32 clip_scaled(u32 src, u32 dst, u32 clip)
{
- u64 tmp = mul_u32_u32(src, dst - clip);
+ u64 tmp;
+
+ if (dst == 0)
+ return 0;
+
+ tmp = mul_u32_u32(src, dst - clip);
/*
* Round toward 1.0 when clipping so that we don't accidentally
--
2.23.0
