Re: [PATCH 1/7] drm/amdgpu/mmhub2.0: add bounds checking for cid

["Lazar, Lijo" <lijo.lazar@amd.com>]

On 05-Mar-26 3:57 AM, Alex Deucher wrote:
> The value should never exceed the array size as those
> are the only values the hardware is expected to return,
> but add checks anyway.
> 
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
> index a0cc8e218ca1e..534cb4c544dc4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
> @@ -154,14 +154,17 @@ mmhub_v2_0_print_l2_protection_fault_status(struct amdgpu_device *adev,
>   	switch (amdgpu_ip_version(adev, MMHUB_HWIP, 0)) {
>   	case IP_VERSION(2, 0, 0):
>   	case IP_VERSION(2, 0, 2):
> -		mmhub_cid = mmhub_client_ids_navi1x[cid][rw];
> +		mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_navi1x) ?

Does this introduce speculation and requirement to use array_index_nospec?

Thanks,
Lijo

> +			mmhub_client_ids_navi1x[cid][rw] : NULL;
>   		break;
>   	case IP_VERSION(2, 1, 0):
>   	case IP_VERSION(2, 1, 1):
> -		mmhub_cid = mmhub_client_ids_sienna_cichlid[cid][rw];
> +		mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_sienna_cichlid) ?
> +			mmhub_client_ids_sienna_cichlid[cid][rw] : NULL;
>   		break;
>   	case IP_VERSION(2, 1, 2):
> -		mmhub_cid = mmhub_client_ids_beige_goby[cid][rw];
> +		mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_beige_goby) ?
> +			mmhub_client_ids_beige_goby[cid][rw] : NULL;
>   		break;
>   	default:
>   		mmhub_cid = NULL;