[PATCH] drm/amdkfd: check for null dev to avoid a null pointer dereference

[Oded Gabbay]

On Fri, Sep 8, 2017 at 5:13 PM, Colin King <colin.king at canonical.com> wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> The call to kfd_device_by_id can potentially return null, so check that
> dev is null and return with -EINVAL to avoid a null pointer dereference.
>
> Detected by CoverityScan CID#1454629 ("Dereference null return value")
>
> Fixes: 5d71dbc3a588 ("drm/amdkfd: Implement image tiling mode support v2")
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>  drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> index e4a8c2e52cb2..660b3fbade41 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> @@ -892,6 +892,8 @@ static int kfd_ioctl_get_tile_config(struct file *filep,
>         int err = 0;
>
>         dev = kfd_device_by_id(args->gpu_id);
> +       if (!dev)
> +               return -EINVAL;
>
>         dev->kfd2kgd->get_tile_config(dev->kgd, &config);
>
> --
> 2.14.1
>
Thanks!
Applied to my -fixes tree