[patch] drm/amdgpu: potential NULL dereference in debugfs code

[Christian König]

Am 12.10.2016 um 08:17 schrieb Dan Carpenter:
> debugfs_create_file() returns NULL on error, it only returns error
> pointers if debugfs isn't enabled in the config and we checked for that
> earlier so it can't happen.
>
> Fixes: 4f4824b55650 ('drm/amd/amdgpu: Convert ring debugfs entries to binary')
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

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

>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> index 85aeb0a..8d16eaf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> @@ -371,8 +371,8 @@ static int amdgpu_debugfs_ring_init(struct amdgpu_device 
> *adev,
>       ent = debugfs_create_file(name,
>                                 S_IFREG | S_IRUGO, root,
>                                 ring, &amdgpu_debugfs_ring_fops);
> -     if (IS_ERR(ent))
> -             return PTR_ERR(ent);
> +     if (!ent)
> +             return -ENOMEM;
>   
>       i_size_write(ent->d_inode, ring->ring_size + 12);
>       ring->ent = ent;