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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Nikhil Devshatwar <nikhil.nd@ti.com>,
        Benoit Parrot <bparrot@ti.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 046/166] media: ti-vpe: cal: Restrict DMA to avoid memory corruption
Date:   Tue, 29 Sep 2020 12:59:18 +0200
Message-Id: <20200929105937.503880775@linuxfoundation.org>
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From: Nikhil Devshatwar <nikhil.nd@ti.com>

[ Upstream commit 6e72eab2e7b7a157d554b8f9faed7676047be7c1 ]

When setting DMA for video capture from CSI channel, if the DMA size
is not given, it ends up writing as much data as sent by the camera.

This may lead to overwriting the buffers causing memory corruption.
Observed green lines on the default framebuffer.

Restrict the DMA to maximum height as specified in the S_FMT ioctl.

Signed-off-by: Nikhil Devshatwar <nikhil.nd@ti.com>
Signed-off-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/platform/ti-vpe/cal.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/ti-vpe/cal.c b/drivers/media/platform/ti-vpe/cal.c
index b6dcae1ecc1be..ad344e642ddb7 100644
--- a/drivers/media/platform/ti-vpe/cal.c
+++ b/drivers/media/platform/ti-vpe/cal.c
@@ -687,12 +687,13 @@ static void pix_proc_config(struct cal_ctx *ctx)
 }
 
 static void cal_wr_dma_config(struct cal_ctx *ctx,
-			      unsigned int width)
+			      unsigned int width, unsigned int height)
 {
 	u32 val;
 
 	val = reg_read(ctx->dev, CAL_WR_DMA_CTRL(ctx->csi2_port));
 	set_field(&val, ctx->csi2_port, CAL_WR_DMA_CTRL_CPORT_MASK);
+	set_field(&val, height, CAL_WR_DMA_CTRL_YSIZE_MASK);
 	set_field(&val, CAL_WR_DMA_CTRL_DTAG_PIX_DAT,
 		  CAL_WR_DMA_CTRL_DTAG_MASK);
 	set_field(&val, CAL_WR_DMA_CTRL_MODE_CONST,
@@ -1318,7 +1319,8 @@ static int cal_start_streaming(struct vb2_queue *vq, unsigned int count)
 	csi2_lane_config(ctx);
 	csi2_ctx_config(ctx);
 	pix_proc_config(ctx);
-	cal_wr_dma_config(ctx, ctx->v_fmt.fmt.pix.bytesperline);
+	cal_wr_dma_config(ctx, ctx->v_fmt.fmt.pix.bytesperline,
+			  ctx->v_fmt.fmt.pix.height);
 	cal_wr_dma_addr(ctx, addr);
 	csi2_ppi_enable(ctx);
 
-- 
2.25.1