2022-02-28 10:51:22

by Hsin-Yi Wang

Subject: [PATCH] drm/bridge: it6505: Fix the read buffer array bound

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 <[email protected]>
Signed-off-by: Hsin-Yi Wang <[email protected]>
---
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 fb16a176822d81..f2f101220ade94 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)
--
2.35.1.574.g5d30c73bfb-goog

2022-02-28 17:45:47

by Robert Foss

Subject: Re: [PATCH] drm/bridge: it6505: Fix the read buffer array bound

On Mon, 28 Feb 2022 at 09:14, Hsin-Yi Wang <[email protected]> wrote:
>
> 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 <[email protected]>
> Signed-off-by: Hsin-Yi Wang <[email protected]>
> ---
> 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 fb16a176822d81..f2f101220ade94 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)
> --
> 2.35.1.574.g5d30c73bfb-goog
>

Reviewed-by: Robert Foss <[email protected]>

2022-03-01 13:14:23

by Robert Foss

Subject: Re: [PATCH] drm/bridge: it6505: Fix the read buffer array bound

Applied to drm-misc-next.