From 49eb92e1c589c0de7d686b5f99db936b18e65f33 Mon Sep 17 00:00:00 2001
From: Hsin-Yi Wang <hsinyi@chromium.org>
Date: Mon, 28 Feb 2022 16:14:21 +0800
Subject: drm/bridge: it6505: Fix the read buffer array bound
Git-commit: e22dfdb63df36427067fad6b9bfdc8c08371ab38
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

The size of read_buf is READ_BUFFER_SIZE (200), so we can't access it
with read_buf + PAGE_SIZE (4096). Extend the READ_BUFFER_SIZE to 400 and
set the end position to read_buf + READ_BUFFER_SIZE.

Fixes: b5c84a9edcd418 ("drm/bridge: add it6505 driver")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220228081421.1504213-1-hsinyi@chromium.org
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index fb16a176822d..f2f101220ade 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -289,7 +289,7 @@
 #define WORD_LENGTH_20BIT 2
 #define WORD_LENGTH_24BIT 3
 #define DEBUGFS_DIR_NAME "it6505-debugfs"
-#define READ_BUFFER_SIZE 200
+#define READ_BUFFER_SIZE 400
 
 /* Vendor option */
 #define HDCP_DESIRED 1
@@ -3074,7 +3074,7 @@ static ssize_t receive_timing_debugfs_show(struct file *file, char __user *buf,
 	struct it6505 *it6505 = file->private_data;
 	struct drm_display_mode *vid = &it6505->video_info;
 	u8 read_buf[READ_BUFFER_SIZE];
-	u8 *str = read_buf, *end = read_buf + PAGE_SIZE;
+	u8 *str = read_buf, *end = read_buf + READ_BUFFER_SIZE;
 	ssize_t ret, count;
 
 	if (!it6505)
-- 
2.38.1