Re: [PATCH] firmware: qcom: pas_tee: handle a NULL resource table

[Jorge Ramirez <jorge.ramirez@oss.qualcomm.com>]

On 06/10/26 08:41:49, Jorge Ramirez-Ortiz wrote:
> Stopping a remote processor clears its cached resource table pointer
> but leaves the size set. On restart, qcom_pas_tee_get_rsc_table() copies
> from NULL when the firmware has no resource table:
> 
>   pc : __pi_memcpy_generic+0x110/0x22c
>   lr : qcom_pas_tee_get_rsc_table+0xf0/0x244
> 
> Zero the input size when the table is NULL so the copy is skipped.
> 
> Fixes: b6f7978da0c4 ("firmware: qcom: Add a PAS TEE service")
> Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@oss.qualcomm.com>
> ---
>  drivers/firmware/qcom/qcom_pas_tee.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/qcom/qcom_pas_tee.c b/drivers/firmware/qcom/qcom_pas_tee.c
> index ac33a00687aa..a52a7df385ff 100644
> --- a/drivers/firmware/qcom/qcom_pas_tee.c
> +++ b/drivers/firmware/qcom/qcom_pas_tee.c
> @@ -230,12 +230,15 @@ static void *qcom_pas_tee_get_rsc_table(struct device *dev,
>  		},
>  		[1] = {
>  			.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
> -			.u.memref.size = input_rt_size,
>  		}
>  	};
>  	void *rt_buf = NULL;
>  	int ret;
>  
> +	if (!input_rt)
> +		input_rt_size = 0;
> +	param[1].u.memref.size = input_rt_size;
> +
>  	ret = tee_client_invoke_func(data->ctx, &inv_arg, param);
>  	if (ret < 0 || inv_arg.ret != 0) {
>  		dev_err(dev, "PAS get RT failed, pas_id: %d, ret: %d, err: 0x%x\n",
> -- 
> 2.54.0
> 

could  we merge this? as mentioned, it  protects against blindly
dereferencin a pointer that might be null. I submitted another patch
that should address the issue in a higher level interface but regardless
I see nothing wrong with catching it here as well.

TIA