drm/radeon: Avoid open coded arithmetic in memory allocation

[PATCH] drm/radeon: Avoid open coded arithmetic in memory allocation

Posted by Christophe JAILLET 4 years, 4 months ago

kmalloc_array()/kcalloc() should be used to avoid potential overflow when
a multiplication is needed to compute the size of the requested memory.

So turn a kzalloc()+explicit size computation into an equivalent kcalloc().

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/gpu/drm/radeon/radeon_atombios.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index 28c4413f4dc8..7b9cc7a9f42f 100644
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -897,13 +897,13 @@ bool radeon_get_atom_connector_info_from_supported_devices_table(struct
 	union atom_supported_devices *supported_devices;
 	int i, j, max_device;
 	struct bios_connector *bios_connectors;
-	size_t bc_size = sizeof(*bios_connectors) * ATOM_MAX_SUPPORTED_DEVICE;
 	struct radeon_router router;
 
 	router.ddc_valid = false;
 	router.cd_valid = false;
 
-	bios_connectors = kzalloc(bc_size, GFP_KERNEL);
+	bios_connectors = kcalloc(ATOM_MAX_SUPPORTED_DEVICE,
+				  sizeof(*bios_connectors), GFP_KERNEL);
 	if (!bios_connectors)
 		return false;
 
-- 
2.32.0

Re: [PATCH] drm/radeon: Avoid open coded arithmetic in memory allocation

Posted by Christian König 4 years, 4 months ago

Am 05.02.22 um 18:38 schrieb Christophe JAILLET:
> kmalloc_array()/kcalloc() should be used to avoid potential overflow when
> a multiplication is needed to compute the size of the requested memory.
>
> So turn a kzalloc()+explicit size computation into an equivalent kcalloc().
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/gpu/drm/radeon/radeon_atombios.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
> index 28c4413f4dc8..7b9cc7a9f42f 100644
> --- a/drivers/gpu/drm/radeon/radeon_atombios.c
> +++ b/drivers/gpu/drm/radeon/radeon_atombios.c
> @@ -897,13 +897,13 @@ bool radeon_get_atom_connector_info_from_supported_devices_table(struct
>   	union atom_supported_devices *supported_devices;
>   	int i, j, max_device;
>   	struct bios_connector *bios_connectors;
> -	size_t bc_size = sizeof(*bios_connectors) * ATOM_MAX_SUPPORTED_DEVICE;
>   	struct radeon_router router;
>   
>   	router.ddc_valid = false;
>   	router.cd_valid = false;
>   
> -	bios_connectors = kzalloc(bc_size, GFP_KERNEL);
> +	bios_connectors = kcalloc(ATOM_MAX_SUPPORTED_DEVICE,
> +				  sizeof(*bios_connectors), GFP_KERNEL);
>   	if (!bios_connectors)
>   		return false;
>