Re: [PATCH] platform/surface: aggregator: Fix access of unaligned value

[mark gross]

Acked-by: Mark Gross <mgross@xxxxxxxxxxxxxx>

On Thu, Feb 11, 2021 at 12:04:11AM +0100, Maximilian Luz wrote:
> The raw message frame length is unaligned and explicitly marked as
> little endian. It should not be accessed without the appropriatte
> accessor functions. Fix this.
> 
> Reported-by: kernel-test-robot <lkp@xxxxxxxxx>
> Fixes: c167b9c7e3d6 ("platform/surface: Add Surface Aggregator subsystem")
> Signed-off-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
> ---
>  drivers/platform/surface/aggregator/ssh_packet_layer.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/surface/aggregator/ssh_packet_layer.c b/drivers/platform/surface/aggregator/ssh_packet_layer.c
> index 583315db8b02..9a78188d8d1c 100644
> --- a/drivers/platform/surface/aggregator/ssh_packet_layer.c
> +++ b/drivers/platform/surface/aggregator/ssh_packet_layer.c
> @@ -1774,7 +1774,8 @@ static size_t ssh_ptl_rx_eval(struct ssh_ptl *ptl, struct ssam_span *source)
>  		break;
>  	}
>  
> -	return aligned.ptr - source->ptr + SSH_MESSAGE_LENGTH(frame->len);
> +	return aligned.ptr - source->ptr
> +		+ SSH_MESSAGE_LENGTH(get_unaligned_le16(&frame->len));
>  }
>  
>  static int ssh_ptl_rx_threadfn(void *data)
> -- 
> 2.30.0
>