| From 433480c1afd44f3e1e664b85063d98cefeefa0ed Mon Sep 17 00:00:00 2001 |
| From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com> |
| Date: Fri, 22 Nov 2019 19:56:20 +0200 |
| Subject: drm/rect: Avoid division by zero |
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| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Ville Syrjälä <ville.syrjala@linux.intel.com> |
| |
| commit 433480c1afd44f3e1e664b85063d98cefeefa0ed upstream. |
| |
| Check for zero width/height destination rectangle in |
| drm_rect_clip_scaled() to avoid a division by zero. |
| |
| Cc: stable@vger.kernel.org |
| Fixes: f96bdf564f3e ("drm/rect: Handle rounding errors in drm_rect_clip_scaled, v3.") |
| Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> |
| Cc: Benjamin Gaignard <benjamin.gaignard@st.com> |
| Cc: Daniel Vetter <daniel@ffwll.ch> |
| Testcase: igt/kms_selftest/drm_rect_clip_scaled_div_by_zero |
| Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> |
| Link: https://patchwork.freedesktop.org/patch/msgid/20191122175623.13565-2-ville.syrjala@linux.intel.com |
| Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> |
| Reviewed-by: Benjamin Gaignard <benjamin.gaignard@st.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/gpu/drm/drm_rect.c | 7 ++++++- |
| 1 file changed, 6 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/gpu/drm/drm_rect.c |
| +++ b/drivers/gpu/drm/drm_rect.c |
| @@ -52,7 +52,12 @@ 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 |