Subject: Re: [PATCH net v4] net: nfc: nci: Fix parameter validation for packet data

From: Jakub Kicinski <[email-masked]>
Date: Sun, 4 Jan 2026 10:13:23 -0800

On Tue, 23 Dec 2025 08:25:52 +0100 Michael Thalmeier wrote:
> diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c
> index 418b84e2b260..a5cafcd10cc3 100644
> --- a/net/nfc/nci/ntf.c
> +++ b/net/nfc/nci/ntf.c

> @@ -380,6 +384,10 @@ static int nci_rf_discover_ntf_packet(struct nci_dev *ndev,
>  	pr_debug("rf_tech_specific_params_len %d\n",
>  		 ntf.rf_tech_specific_params_len);
>  
> +	if (skb->len < (data - skb->data) +
> +			ntf.rf_tech_specific_params_len + sizeof(ntf.ntf_type))
> +		return -EINVAL;

Are we validating ntf.rf_tech_specific_params_len against the
extraction logic in nci_extract_rf_params_nfca_passive_poll()
and friends?