[PATCH] Fix IB va_start+ib_bytes range check on 32Bit systems

[deathsimple@xxxxxxxxxxx (Christian König)]

Am 29.03.2017 um 11:18 schrieb Jan Burgmeier:
> Signed-off-by: Jan Burgmeier <jan.burgmeier at unicon-software.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index 99424cb8020b..583d22974e14 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -908,6 +908,7 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device *adev,
>   			struct amdgpu_bo *aobj = NULL;
>   			uint64_t offset;
>   			uint8_t *kptr;
> +			uint64_t it_last;
>   
>   			m = amdgpu_cs_find_mapping(parser, chunk_ib->va_start,
>   						   &aobj);
> @@ -916,8 +917,9 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device *adev,
>   				return -EINVAL;
>   			}
>   
> +			it_last = m->it.last;
>   			if ((chunk_ib->va_start + chunk_ib->ib_bytes) >
> -			    (m->it.last + 1) * AMDGPU_GPU_PAGE_SIZE) {
> +			    (it_last + 1) * AMDGPU_GPU_PAGE_SIZE) {

Nice catch, but just adding a u64 case should do here as well. E.g:

if ((chunk_ib->va_start + chunk_ib->ib_bytes) >
     (u64)(m->it.last + 1) * AMDGPU_GPU_PAGE_SIZE) {

With that fixed the patch is Reviewed-by: Christian König 
<christian.koenig at amd.com>.

Regards,
Christian.

>   				DRM_ERROR("IB va_start+ib_bytes is invalid\n");
>   				return -EINVAL;
>   			}