media: platform: mtk-mdp3: fix potential frame size overflow in mdp_try_fmt_mplane()

Fix overflow risk when setting certain formats whose frame size exceeds
a RGB24 with 7723x7723 resolution.

For example, a 7723x7724 RGB24 frame:
    1. bpl (byte per line) = 7723 * 3.
    2. Overflow occurs when bpl * 7724 * depth.

Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-regs.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-regs.c
index 4e84a37ecdfc1a7ce0bbc3ad8d227d8654b819c3..36336d169bd912507138cd64ca8673e0317922fa 100644 (file)
--- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-regs.c
+++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-regs.c
@@ -4,6 +4,7 @@
  * Author: Ping-Hsun Wu <ping-hsun.wu@mediatek.com>
  */
 
+#include <linux/math64.h>
 #include <media/v4l2-common.h>
 #include <media/videobuf2-v4l2.h>
 #include <media/videobuf2-dma-contig.h>
@@ -428,14 +429,15 @@ const struct mdp_format *mdp_try_fmt_mplane(struct v4l2_format *f,
                u32 bpl = pix_mp->plane_fmt[i].bytesperline;
                u32 min_si, max_si;
                u32 si = pix_mp->plane_fmt[i].sizeimage;
+               u64 di;
 
                bpl = clamp(bpl, min_bpl, max_bpl);
                pix_mp->plane_fmt[i].bytesperline = bpl;
 
-               min_si = (bpl * pix_mp->height * fmt->depth[i]) /
-                        fmt->row_depth[i];
-               max_si = (bpl * s.max_height * fmt->depth[i]) /
-                        fmt->row_depth[i];
+               di = (u64)bpl * pix_mp->height * fmt->depth[i];
+               min_si = (u32)div_u64(di, fmt->row_depth[i]);
+               di = (u64)bpl * s.max_height * fmt->depth[i];
+               max_si = (u32)div_u64(di, fmt->row_depth[i]);
 
                si = clamp(si, min_si, max_si);
                pix_mp->plane_fmt[i].sizeimage = si;