Re: [PATCH] NFC: st21nfca: fix st21nfca_get_iso14443_3_uid data copy

[Nicolas Iooss <nicolas.iooss_linux@m4x.org>]

Hello,
I have not received any comments about this patch so I'm sending it
again.  Could you please review it?

Nicolas

On 03/03/2015 12:58 PM, Nicolas Iooss wrote:
> st21nfca_get_iso14443_3_uid() does not correctly copy the uid from
> uid_skb->data to its gate parameter.  "gate = uid_skb->data;" only puts
> a pointer to uid_skb->data to the local variable gate.  This means that
> in st21nfca_hci_target_from_gate() the content of "u8
> uid[NFC_NFCID1_MAXSIZE]" local variable is never initialized before
> being used in memcpy(target->nfcid1, uid, len).
> 
> Fix this by replacing the local variable assignment with a memcpy.
> 
> This was found by compiling Linux with "gcc -Wunused-but-set-parameter".
> 
> Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
> ---
> 
> As I did not get any reply from https://lkml.org/lkml/2015/2/28/25 and
> got confirmation by other people that this may be a real bug, I am now
> sending a patch to fix it.
> 
>  drivers/nfc/st21nfca/st21nfca.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/nfc/st21nfca/st21nfca.c b/drivers/nfc/st21nfca/st21nfca.c
> index 24d3d240d5f4..ff70d2838b29 100644
> --- a/drivers/nfc/st21nfca/st21nfca.c
> +++ b/drivers/nfc/st21nfca/st21nfca.c
> @@ -588,7 +588,7 @@ static int st21nfca_get_iso14443_3_uid(struct nfc_hci_dev *hdev, u8 *gate,
>  		goto exit;
>  	}
>  
> -	gate = uid_skb->data;
> +	memcpy(gate, uid_skb->data, uid_skb->len);
>  	*len = uid_skb->len;
>  exit:
>  	kfree_skb(uid_skb);
>