Re: [PATCH] nvmet_tcp: fix header digest verification

[Sagi Grimberg <sagi@grimberg.me>]

> pass the correct length to nvmet_tcp_hdgst.
> when verify_hdgst, need to pass pdu header len.
> This fixes a wrong behaviour where
> header digest verification pass although digest is wrong

Amit, can you describe what you mean here?
what is wrong about the digest?

What is currently passed in len is queue->offset, which is
the temporary offset from the pdu, which is equal to hdr->hlen
because we verify the digest right after we finish reading the PDU
header.

> 
> Signed-off-by: Amit Engel <amit.engel@dell.com>
> ---
>   drivers/nvme/target/tcp.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
> index 6eb0b3153477..954c27a94561 100644
> --- a/drivers/nvme/target/tcp.c
> +++ b/drivers/nvme/target/tcp.c
> @@ -268,7 +268,7 @@ static int nvmet_tcp_verify_hdgst(struct nvmet_tcp_queue *queue,
>   	}
>   
>   	recv_digest = *(__le32 *)(pdu + hdr->hlen);
> -	nvmet_tcp_hdgst(queue->rcv_hash, pdu, len);
> +	nvmet_tcp_hdgst(queue->rcv_hash, pdu, hdr->hlen);

If at all, the caller should pass hdr->hlen and keep this generic.