Re: [PATCH] drm/panthor: Fix off by one in panthor_fw_get_cs_iface()

[Boris Brezillon]

On Tue, 2 Apr 2024 12:56:42 +0300
Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:

> The ->iface.streams[csg_slot][] array has MAX_CS_PER_CSG elements so
> this > comparison needs to be >= to prevent an out of bounds access.
> 
> Fixes: 2718d91816ee ("drm/panthor: Add the FW logical block")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>

> ---
>  drivers/gpu/drm/panthor/panthor_fw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
> index 33c87a59834e..181395e2859a 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> @@ -308,7 +308,7 @@ panthor_fw_get_csg_iface(struct panthor_device *ptdev, u32 csg_slot)
>  struct panthor_fw_cs_iface *
>  panthor_fw_get_cs_iface(struct panthor_device *ptdev, u32 csg_slot, u32 cs_slot)
>  {
> -	if (drm_WARN_ON(&ptdev->base, csg_slot >= MAX_CSGS || cs_slot > MAX_CS_PER_CSG))
> +	if (drm_WARN_ON(&ptdev->base, csg_slot >= MAX_CSGS || cs_slot >= MAX_CS_PER_CSG))
>  		return NULL;
>  
>  	return &ptdev->fw->iface.streams[csg_slot][cs_slot];