[PATCH] drm: amdgpu: Use the correct size when allocating memory

[Christian König]

Am 09.08.20 um 22:34 schrieb Christophe JAILLET:
> When '*sgt' is allocated, we must allocated 'sizeof(**sgt)' bytes instead
> of 'sizeof(*sg)'. 'sg' (i.e. struct scatterlist) is smaller than
> 'sgt' (i.e struct sg_table), so this could lead to memory corruption.
>
> Fixes: f44ffd677fb3 ("drm/amdgpu: add support for exporting VRAM using DMA-buf v3")
> Signed-off-by: Christophe JAILLET <christophe.jaillet at wanadoo.fr>

Good catch, Reviewed-by: Christian König <christian.koenig at amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 134cc36e30c5..0739e259bf91 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -462,7 +462,7 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
>   	unsigned int pages;
>   	int i, r;
>   
> -	*sgt = kmalloc(sizeof(*sg), GFP_KERNEL);
> +	*sgt = kmalloc(sizeof(**sgt), GFP_KERNEL);
>   	if (!*sgt)
>   		return -ENOMEM;
>