[PATCH] drm/amd/display: Fix a potential buffer overflow in 'dp_dsc_clock_en_read()'

[PATCH] drm/amd/display: Fix a potential buffer overflow in 'dp_dsc_clock_en_read()'

[Srinivasan Shanmugam]

Tell snprintf() to store at most 10 bytes in the output buffer
instead of 30.

Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_debugfs.c:1508 dp_dsc_clock_en_read() error: snprintf() is printing too much 30 vs 10

Fixes: c06e09b76639 ("drm/amd/display: Add DSC parameters logging to debugfs")
Cc: Alex Hung <alex.hung@amd.com>
Cc: Qingqing Zhuo <qingqing.zhuo@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 68a846323912..85fc6181303b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -1483,7 +1483,7 @@ static ssize_t dp_dsc_clock_en_read(struct file *f, char __user *buf,
 	const uint32_t rd_buf_size = 10;
 	struct pipe_ctx *pipe_ctx;
 	ssize_t result = 0;
-	int i, r, str_len = 30;
+	int i, r, str_len = 10;
 
 	rd_buf = kcalloc(rd_buf_size, sizeof(char), GFP_KERNEL);
 
-- 
2.34.1

Re: [PATCH] drm/amd/display: Fix a potential buffer overflow in 'dp_dsc_clock_en_read()'

[Harry Wentland]

On 2024-01-23 10:01, Srinivasan Shanmugam wrote:
> Tell snprintf() to store at most 10 bytes in the output buffer
> instead of 30.
> 
> Fixes the below:
> drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_debugfs.c:1508 dp_dsc_clock_en_read() error: snprintf() is printing too much 30 vs 10
> 
> Fixes: c06e09b76639 ("drm/amd/display: Add DSC parameters logging to debugfs")
> Cc: Alex Hung <alex.hung@amd.com>
> Cc: Qingqing Zhuo <qingqing.zhuo@amd.com>
> Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
> Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>

Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
> index 68a846323912..85fc6181303b 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
> @@ -1483,7 +1483,7 @@ static ssize_t dp_dsc_clock_en_read(struct file *f, char __user *buf,
>  	const uint32_t rd_buf_size = 10;
>  	struct pipe_ctx *pipe_ctx;
>  	ssize_t result = 0;
> -	int i, r, str_len = 30;
> +	int i, r, str_len = 10;
>  
>  	rd_buf = kcalloc(rd_buf_size, sizeof(char), GFP_KERNEL);
>