[PATCH] drm/exynos: dpi: Fix NULL pointer dereference with legacy bindings

[PATCH] drm/exynos: dpi: Fix NULL pointer dereference with legacy bindings

[Tomasz Figa]

If there is no panel node in DT and instead display timings are provided
directly in FIMD node, there is no panel object created and ctx->panel
becomes NULL. However during Exynos DRM initialization
drm_helper_hpd_irq_event() is called, which in turns calls
exynos_dpi_detect(), which dereferences ctx->panel without a check,
causing a NULL pointer derefrence.

This patch fixes the issue by adding necessary NULL pointer check.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
---
 drivers/gpu/drm/exynos/exynos_drm_dpi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dpi.c b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
index f1b8587..f44bd90 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dpi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
@@ -40,7 +40,7 @@ exynos_dpi_detect(struct drm_connector *connector, bool force)
 {
 	struct exynos_dpi *ctx = connector_to_dpi(connector);
 
-	if (!ctx->panel->connector)
+	if (ctx->panel && !ctx->panel->connector)
 		drm_panel_attach(ctx->panel, &ctx->connector);
 
 	return connector_status_connected;
-- 
2.0.0

Re: [PATCH] drm/exynos: dpi: Fix NULL pointer dereference with legacy bindings

[Tomasz Figa]

On 10.06.2014 22:57, Tomasz Figa wrote:
> If there is no panel node in DT and instead display timings are provided
> directly in FIMD node, there is no panel object created and ctx->panel
> becomes NULL. However during Exynos DRM initialization
> drm_helper_hpd_irq_event() is called, which in turns calls
> exynos_dpi_detect(), which dereferences ctx->panel without a check,
> causing a NULL pointer derefrence.
> 
> This patch fixes the issue by adding necessary NULL pointer check.
> 
> Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_dpi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dpi.c b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
> index f1b8587..f44bd90 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_dpi.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
> @@ -40,7 +40,7 @@ exynos_dpi_detect(struct drm_connector *connector, bool force)
>  {
>  	struct exynos_dpi *ctx = connector_to_dpi(connector);
>  
> -	if (!ctx->panel->connector)
> +	if (ctx->panel && !ctx->panel->connector)
>  		drm_panel_attach(ctx->panel, &ctx->connector);
>  
>  	return connector_status_connected;
> 

Ping.

Best regards,
Tomasz

Re: [PATCH] drm/exynos: dpi: Fix NULL pointer dereference with legacy bindings

[Jingoo Han]

On Wednesday, June 11, 2014 5:58 AM, Tomasz Figa wrote:
> 
> If there is no panel node in DT and instead display timings are provided
> directly in FIMD node, there is no panel object created and ctx->panel
> becomes NULL. However during Exynos DRM initialization
> drm_helper_hpd_irq_event() is called, which in turns calls
> exynos_dpi_detect(), which dereferences ctx->panel without a check,
> causing a NULL pointer derefrence.
> 
> This patch fixes the issue by adding necessary NULL pointer check.
> 
> Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>

(+cc Inki Dae)

Reviewed-by: Jingoo Han <jg1.han@samsung.com>

Best regards,
Jingoo Han

> ---
>  drivers/gpu/drm/exynos/exynos_drm_dpi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dpi.c b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
> index f1b8587..f44bd90 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_dpi.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
> @@ -40,7 +40,7 @@ exynos_dpi_detect(struct drm_connector *connector, bool force)
>  {
>  	struct exynos_dpi *ctx = connector_to_dpi(connector);
> 
> -	if (!ctx->panel->connector)
> +	if (ctx->panel && !ctx->panel->connector)
>  		drm_panel_attach(ctx->panel, &ctx->connector);
> 
>  	return connector_status_connected;
> --

Re: [PATCH] drm/exynos: dpi: Fix NULL pointer dereference with legacy bindings

[Inki Dae]

On 2014년 06월 18일 09:09, Tomasz Figa wrote:
> On 10.06.2014 22:57, Tomasz Figa wrote:
>> If there is no panel node in DT and instead display timings are provided
>> directly in FIMD node, there is no panel object created and ctx->panel
>> becomes NULL. However during Exynos DRM initialization
>> drm_helper_hpd_irq_event() is called, which in turns calls
>> exynos_dpi_detect(), which dereferences ctx->panel without a check,
>> causing a NULL pointer derefrence.
>>
>> This patch fixes the issue by adding necessary NULL pointer check.
>>
>> Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
>> ---
>>  drivers/gpu/drm/exynos/exynos_drm_dpi.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dpi.c b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
>> index f1b8587..f44bd90 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_dpi.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
>> @@ -40,7 +40,7 @@ exynos_dpi_detect(struct drm_connector *connector, bool force)
>>  {
>>  	struct exynos_dpi *ctx = connector_to_dpi(connector);
>>  
>> -	if (!ctx->panel->connector)
>> +	if (ctx->panel && !ctx->panel->connector)
>>  		drm_panel_attach(ctx->panel, &ctx->connector);
>>  
>>  	return connector_status_connected;
>>
> 
> Ping.

Applied.

Thanks,
Inki Dae

> 
> Best regards,
> Tomasz
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