From: Pin-Yen Lin <treapking@chromium.org>
Date: Thu, 10 Feb 2022 10:38:27 +0000 (+0800)
Subject: drm/bridge: anx7625: Fix overflow issue on reading EDID
X-Git-Tag: v5.17.2~581
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=db1c47d299298a7c52ccb201905d6be979fd7507;p=users%2Fdwmw2%2Flinux.git

drm/bridge: anx7625: Fix overflow issue on reading EDID

[ Upstream commit d5c6f647aec9ed524aedd04a3aec5ebc21d39007 ]

The length of EDID block can be longer than 256 bytes, so we should use
`int` instead of `u8` for the `edid_pos` variable.

Fixes: 8bdfc5dae4e3 ("drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP")
Signed-off-by: Pin-Yen Lin <treapking@chromium.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220210103827.402436-1-treapking@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 2346dbcc505f2..e596cacce9e3e 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -846,7 +846,8 @@ static int segments_edid_read(struct anx7625_data *ctx,
 static int sp_tx_edid_read(struct anx7625_data *ctx,
 			   u8 *pedid_blocks_buf)
 {
-	u8 offset, edid_pos;
+	u8 offset;
+	int edid_pos;
 	int count, blocks_num;
 	u8 pblock_buf[MAX_DPCD_BUFFER_SIZE];
 	u8 i, j;