[PATCH] drm/plane: Move range check for format_count earlier

[PATCH] drm/plane: Move range check for format_count earlier

[Steven Price]

While the check for format_count > 64 in __drm_universal_plane_init()
shouldn't be hit (it's a WARN_ON), in its current position it will then
leak the plane->format_types array and fail to call
drm_mode_object_unregister() leaking the modeset identifier. Move it to
the start of the function to avoid allocating those resources in the
first place.

Signed-off-by: Steven Price <steven.price@arm.com>
---
 drivers/gpu/drm/drm_plane.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 82afb854141b..fd0bf90fb4c2 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
 	if (WARN_ON(config->num_total_plane >= 32))
 		return -EINVAL;
 
+	/*
+	 * First driver to need more than 64 formats needs to fix this. Each
+	 * format is encoded as a bit and the current code only supports a u64.
+	 */
+	if (WARN_ON(format_count > 64))
+		return -EINVAL;
+
 	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
 		(!funcs->atomic_destroy_state ||
 		 !funcs->atomic_duplicate_state));
@@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
 		return -ENOMEM;
 	}
 
-	/*
-	 * First driver to need more than 64 formats needs to fix this. Each
-	 * format is encoded as a bit and the current code only supports a u64.
-	 */
-	if (WARN_ON(format_count > 64))
-		return -EINVAL;
-
 	if (format_modifiers) {
 		const uint64_t *temp_modifiers = format_modifiers;
 
-- 
2.25.1

[PATCH] drm/plane: Move range check for format_count earlier

[Steven Price]

While the check for format_count > 64 in __drm_universal_plane_init()
shouldn't be hit (it's a WARN_ON), in its current position it will then
leak the plane->format_types array and fail to call
drm_mode_object_unregister() leaking the modeset identifier. Move it to
the start of the function to avoid allocating those resources in the
first place.

Signed-off-by: Steven Price <steven.price@arm.com>
---
 drivers/gpu/drm/drm_plane.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 82afb854141b..fd0bf90fb4c2 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
 	if (WARN_ON(config->num_total_plane >= 32))
 		return -EINVAL;
 
+	/*
+	 * First driver to need more than 64 formats needs to fix this. Each
+	 * format is encoded as a bit and the current code only supports a u64.
+	 */
+	if (WARN_ON(format_count > 64))
+		return -EINVAL;
+
 	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
 		(!funcs->atomic_destroy_state ||
 		 !funcs->atomic_duplicate_state));
@@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
 		return -ENOMEM;
 	}
 
-	/*
-	 * First driver to need more than 64 formats needs to fix this. Each
-	 * format is encoded as a bit and the current code only supports a u64.
-	 */
-	if (WARN_ON(format_count > 64))
-		return -EINVAL;
-
 	if (format_modifiers) {
 		const uint64_t *temp_modifiers = format_modifiers;
 
-- 
2.25.1

Re: [PATCH] drm/plane: Move range check for format_count earlier

[Liviu Dudau]

On Fri, Dec 03, 2021 at 10:28:15AM +0000, Steven Price wrote:
> While the check for format_count > 64 in __drm_universal_plane_init()
> shouldn't be hit (it's a WARN_ON), in its current position it will then
> leak the plane->format_types array and fail to call
> drm_mode_object_unregister() leaking the modeset identifier. Move it to
> the start of the function to avoid allocating those resources in the
> first place.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>

Well spotted!

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

I'm going to wait to see if anyone else has any comments before I'll merge this into
drm-misc-fixes (or should it be drm-misc-next-fixes?)

Best regards,
Liviu

> ---
>  drivers/gpu/drm/drm_plane.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 82afb854141b..fd0bf90fb4c2 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>  	if (WARN_ON(config->num_total_plane >= 32))
>  		return -EINVAL;
>  
> +	/*
> +	 * First driver to need more than 64 formats needs to fix this. Each
> +	 * format is encoded as a bit and the current code only supports a u64.
> +	 */
> +	if (WARN_ON(format_count > 64))
> +		return -EINVAL;
> +
>  	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
>  		(!funcs->atomic_destroy_state ||
>  		 !funcs->atomic_duplicate_state));
> @@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>  		return -ENOMEM;
>  	}
>  
> -	/*
> -	 * First driver to need more than 64 formats needs to fix this. Each
> -	 * format is encoded as a bit and the current code only supports a u64.
> -	 */
> -	if (WARN_ON(format_count > 64))
> -		return -EINVAL;
> -
>  	if (format_modifiers) {
>  		const uint64_t *temp_modifiers = format_modifiers;
>  
> -- 
> 2.25.1
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

Re: [PATCH] drm/plane: Move range check for format_count earlier

[Liviu Dudau]

On Fri, Dec 03, 2021 at 10:28:15AM +0000, Steven Price wrote:
> While the check for format_count > 64 in __drm_universal_plane_init()
> shouldn't be hit (it's a WARN_ON), in its current position it will then
> leak the plane->format_types array and fail to call
> drm_mode_object_unregister() leaking the modeset identifier. Move it to
> the start of the function to avoid allocating those resources in the
> first place.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>

Well spotted!

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

I'm going to wait to see if anyone else has any comments before I'll merge this into
drm-misc-fixes (or should it be drm-misc-next-fixes?)

Best regards,
Liviu

> ---
>  drivers/gpu/drm/drm_plane.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 82afb854141b..fd0bf90fb4c2 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>  	if (WARN_ON(config->num_total_plane >= 32))
>  		return -EINVAL;
>  
> +	/*
> +	 * First driver to need more than 64 formats needs to fix this. Each
> +	 * format is encoded as a bit and the current code only supports a u64.
> +	 */
> +	if (WARN_ON(format_count > 64))
> +		return -EINVAL;
> +
>  	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
>  		(!funcs->atomic_destroy_state ||
>  		 !funcs->atomic_duplicate_state));
> @@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>  		return -ENOMEM;
>  	}
>  
> -	/*
> -	 * First driver to need more than 64 formats needs to fix this. Each
> -	 * format is encoded as a bit and the current code only supports a u64.
> -	 */
> -	if (WARN_ON(format_count > 64))
> -		return -EINVAL;
> -
>  	if (format_modifiers) {
>  		const uint64_t *temp_modifiers = format_modifiers;
>  
> -- 
> 2.25.1
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

Re: [PATCH] drm/plane: Move range check for format_count earlier

[Carsten Haitzler]

On 12/3/21 13:08, Liviu Dudau wrote:
> On Fri, Dec 03, 2021 at 10:28:15AM +0000, Steven Price wrote:
>> While the check for format_count > 64 in __drm_universal_plane_init()
>> shouldn't be hit (it's a WARN_ON), in its current position it will then
>> leak the plane->format_types array and fail to call
>> drm_mode_object_unregister() leaking the modeset identifier. Move it to
>> the start of the function to avoid allocating those resources in the
>> first place.
>>
>> Signed-off-by: Steven Price <steven.price@arm.com>
> 
> Well spotted!
> 
> Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
> 
> I'm going to wait to see if anyone else has any comments before I'll merge this into
> drm-misc-fixes (or should it be drm-misc-next-fixes?)

This definitely looks to fix an ugly I spotted too while looking at your 
prior patch thinking it might be wrong so a +1 from me.

> Best regards,
> Liviu
> 
>> ---
>>   drivers/gpu/drm/drm_plane.c | 14 +++++++-------
>>   1 file changed, 7 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
>> index 82afb854141b..fd0bf90fb4c2 100644
>> --- a/drivers/gpu/drm/drm_plane.c
>> +++ b/drivers/gpu/drm/drm_plane.c
>> @@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>>   	if (WARN_ON(config->num_total_plane >= 32))
>>   		return -EINVAL;
>>   
>> +	/*
>> +	 * First driver to need more than 64 formats needs to fix this. Each
>> +	 * format is encoded as a bit and the current code only supports a u64.
>> +	 */
>> +	if (WARN_ON(format_count > 64))
>> +		return -EINVAL;
>> +
>>   	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
>>   		(!funcs->atomic_destroy_state ||
>>   		 !funcs->atomic_duplicate_state));
>> @@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>>   		return -ENOMEM;
>>   	}
>>   
>> -	/*
>> -	 * First driver to need more than 64 formats needs to fix this. Each
>> -	 * format is encoded as a bit and the current code only supports a u64.
>> -	 */
>> -	if (WARN_ON(format_count > 64))
>> -		return -EINVAL;
>> -
>>   	if (format_modifiers) {
>>   		const uint64_t *temp_modifiers = format_modifiers;
>>   
>> -- 
>> 2.25.1
>>
> 

Re: [PATCH] drm/plane: Move range check for format_count earlier

[Steven Price]

On 03/12/2021 13:08, Liviu Dudau wrote:
> On Fri, Dec 03, 2021 at 10:28:15AM +0000, Steven Price wrote:
>> While the check for format_count > 64 in __drm_universal_plane_init()
>> shouldn't be hit (it's a WARN_ON), in its current position it will then
>> leak the plane->format_types array and fail to call
>> drm_mode_object_unregister() leaking the modeset identifier. Move it to
>> the start of the function to avoid allocating those resources in the
>> first place.
>>
>> Signed-off-by: Steven Price <steven.price@arm.com>
> 
> Well spotted!
> 
> Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
> 
> I'm going to wait to see if anyone else has any comments before I'll merge this into
> drm-misc-fixes (or should it be drm-misc-next-fixes?)

Gentle ping! I think we've probably waited long enough. Are you going to
merge this or would you like me to?

Thanks,

Steve

> Best regards,
> Liviu
> 
>> ---
>>  drivers/gpu/drm/drm_plane.c | 14 +++++++-------
>>  1 file changed, 7 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
>> index 82afb854141b..fd0bf90fb4c2 100644
>> --- a/drivers/gpu/drm/drm_plane.c
>> +++ b/drivers/gpu/drm/drm_plane.c
>> @@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>>  	if (WARN_ON(config->num_total_plane >= 32))
>>  		return -EINVAL;
>>  
>> +	/*
>> +	 * First driver to need more than 64 formats needs to fix this. Each
>> +	 * format is encoded as a bit and the current code only supports a u64.
>> +	 */
>> +	if (WARN_ON(format_count > 64))
>> +		return -EINVAL;
>> +
>>  	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
>>  		(!funcs->atomic_destroy_state ||
>>  		 !funcs->atomic_duplicate_state));
>> @@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>>  		return -ENOMEM;
>>  	}
>>  
>> -	/*
>> -	 * First driver to need more than 64 formats needs to fix this. Each
>> -	 * format is encoded as a bit and the current code only supports a u64.
>> -	 */
>> -	if (WARN_ON(format_count > 64))
>> -		return -EINVAL;
>> -
>>  	if (format_modifiers) {
>>  		const uint64_t *temp_modifiers = format_modifiers;
>>  
>> -- 
>> 2.25.1
>>
> 

Re: [PATCH] drm/plane: Move range check for format_count earlier

[Steven Price]

On 03/12/2021 13:08, Liviu Dudau wrote:
> On Fri, Dec 03, 2021 at 10:28:15AM +0000, Steven Price wrote:
>> While the check for format_count > 64 in __drm_universal_plane_init()
>> shouldn't be hit (it's a WARN_ON), in its current position it will then
>> leak the plane->format_types array and fail to call
>> drm_mode_object_unregister() leaking the modeset identifier. Move it to
>> the start of the function to avoid allocating those resources in the
>> first place.
>>
>> Signed-off-by: Steven Price <steven.price@arm.com>
> 
> Well spotted!
> 
> Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
> 
> I'm going to wait to see if anyone else has any comments before I'll merge this into
> drm-misc-fixes (or should it be drm-misc-next-fixes?)

Gentle ping! I think we've probably waited long enough. Are you going to
merge this or would you like me to?

Thanks,

Steve

> Best regards,
> Liviu
> 
>> ---
>>  drivers/gpu/drm/drm_plane.c | 14 +++++++-------
>>  1 file changed, 7 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
>> index 82afb854141b..fd0bf90fb4c2 100644
>> --- a/drivers/gpu/drm/drm_plane.c
>> +++ b/drivers/gpu/drm/drm_plane.c
>> @@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>>  	if (WARN_ON(config->num_total_plane >= 32))
>>  		return -EINVAL;
>>  
>> +	/*
>> +	 * First driver to need more than 64 formats needs to fix this. Each
>> +	 * format is encoded as a bit and the current code only supports a u64.
>> +	 */
>> +	if (WARN_ON(format_count > 64))
>> +		return -EINVAL;
>> +
>>  	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
>>  		(!funcs->atomic_destroy_state ||
>>  		 !funcs->atomic_duplicate_state));
>> @@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>>  		return -ENOMEM;
>>  	}
>>  
>> -	/*
>> -	 * First driver to need more than 64 formats needs to fix this. Each
>> -	 * format is encoded as a bit and the current code only supports a u64.
>> -	 */
>> -	if (WARN_ON(format_count > 64))
>> -		return -EINVAL;
>> -
>>  	if (format_modifiers) {
>>  		const uint64_t *temp_modifiers = format_modifiers;
>>  
>> -- 
>> 2.25.1
>>
> 

Re: [PATCH] drm/plane: Move range check for format_count earlier

[Liviu Dudau]

On Thu, Apr 28, 2022 at 12:57:52PM +0100, Steven Price wrote:
> On 03/12/2021 13:08, Liviu Dudau wrote:
> > On Fri, Dec 03, 2021 at 10:28:15AM +0000, Steven Price wrote:
> >> While the check for format_count > 64 in __drm_universal_plane_init()
> >> shouldn't be hit (it's a WARN_ON), in its current position it will then
> >> leak the plane->format_types array and fail to call
> >> drm_mode_object_unregister() leaking the modeset identifier. Move it to
> >> the start of the function to avoid allocating those resources in the
> >> first place.
> >>
> >> Signed-off-by: Steven Price <steven.price@arm.com>
> > 
> > Well spotted!
> > 
> > Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
> > 
> > I'm going to wait to see if anyone else has any comments before I'll merge this into
> > drm-misc-fixes (or should it be drm-misc-next-fixes?)
> 
> Gentle ping! I think we've probably waited long enough. Are you going to
> merge this or would you like me to?

Apologies for dropping this! I will push this one today.

Best regards,
Liviu

> 
> Thanks,
> 
> Steve
> 
> > Best regards,
> > Liviu
> > 
> >> ---
> >>  drivers/gpu/drm/drm_plane.c | 14 +++++++-------
> >>  1 file changed, 7 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> >> index 82afb854141b..fd0bf90fb4c2 100644
> >> --- a/drivers/gpu/drm/drm_plane.c
> >> +++ b/drivers/gpu/drm/drm_plane.c
> >> @@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
> >>  	if (WARN_ON(config->num_total_plane >= 32))
> >>  		return -EINVAL;
> >>  
> >> +	/*
> >> +	 * First driver to need more than 64 formats needs to fix this. Each
> >> +	 * format is encoded as a bit and the current code only supports a u64.
> >> +	 */
> >> +	if (WARN_ON(format_count > 64))
> >> +		return -EINVAL;
> >> +
> >>  	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
> >>  		(!funcs->atomic_destroy_state ||
> >>  		 !funcs->atomic_duplicate_state));
> >> @@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
> >>  		return -ENOMEM;
> >>  	}
> >>  
> >> -	/*
> >> -	 * First driver to need more than 64 formats needs to fix this. Each
> >> -	 * format is encoded as a bit and the current code only supports a u64.
> >> -	 */
> >> -	if (WARN_ON(format_count > 64))
> >> -		return -EINVAL;
> >> -
> >>  	if (format_modifiers) {
> >>  		const uint64_t *temp_modifiers = format_modifiers;
> >>  
> >> -- 
> >> 2.25.1
> >>
> > 
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

Re: [PATCH] drm/plane: Move range check for format_count earlier

[Liviu Dudau]

On Thu, Apr 28, 2022 at 12:57:52PM +0100, Steven Price wrote:
> On 03/12/2021 13:08, Liviu Dudau wrote:
> > On Fri, Dec 03, 2021 at 10:28:15AM +0000, Steven Price wrote:
> >> While the check for format_count > 64 in __drm_universal_plane_init()
> >> shouldn't be hit (it's a WARN_ON), in its current position it will then
> >> leak the plane->format_types array and fail to call
> >> drm_mode_object_unregister() leaking the modeset identifier. Move it to
> >> the start of the function to avoid allocating those resources in the
> >> first place.
> >>
> >> Signed-off-by: Steven Price <steven.price@arm.com>
> > 
> > Well spotted!
> > 
> > Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
> > 
> > I'm going to wait to see if anyone else has any comments before I'll merge this into
> > drm-misc-fixes (or should it be drm-misc-next-fixes?)
> 
> Gentle ping! I think we've probably waited long enough. Are you going to
> merge this or would you like me to?

Apologies for dropping this! I will push this one today.

Best regards,
Liviu

> 
> Thanks,
> 
> Steve
> 
> > Best regards,
> > Liviu
> > 
> >> ---
> >>  drivers/gpu/drm/drm_plane.c | 14 +++++++-------
> >>  1 file changed, 7 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> >> index 82afb854141b..fd0bf90fb4c2 100644
> >> --- a/drivers/gpu/drm/drm_plane.c
> >> +++ b/drivers/gpu/drm/drm_plane.c
> >> @@ -249,6 +249,13 @@ static int __drm_universal_plane_init(struct drm_device *dev,
> >>  	if (WARN_ON(config->num_total_plane >= 32))
> >>  		return -EINVAL;
> >>  
> >> +	/*
> >> +	 * First driver to need more than 64 formats needs to fix this. Each
> >> +	 * format is encoded as a bit and the current code only supports a u64.
> >> +	 */
> >> +	if (WARN_ON(format_count > 64))
> >> +		return -EINVAL;
> >> +
> >>  	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
> >>  		(!funcs->atomic_destroy_state ||
> >>  		 !funcs->atomic_duplicate_state));
> >> @@ -270,13 +277,6 @@ static int __drm_universal_plane_init(struct drm_device *dev,
> >>  		return -ENOMEM;
> >>  	}
> >>  
> >> -	/*
> >> -	 * First driver to need more than 64 formats needs to fix this. Each
> >> -	 * format is encoded as a bit and the current code only supports a u64.
> >> -	 */
> >> -	if (WARN_ON(format_count > 64))
> >> -		return -EINVAL;
> >> -
> >>  	if (format_modifiers) {
> >>  		const uint64_t *temp_modifiers = format_modifiers;
> >>  
> >> -- 
> >> 2.25.1
> >>
> > 
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯