nvme: fix handling of tls alerts

[Chaitanya Kulkarni]

  (+linux-nvme)

On 4/11/26 23:32, Paul Moses wrote:
>> So the patch above fixes this issue?  Or it does not fix the issue?
>>
> It seems like it does more than it needs to and needed more work, but
> yes. My goal is to avoid repeating shaper.c and have maintainer
> input before testing the fix extensively and hopefully save some time.
>
> I'd lean toward something more like this but maintainers have
> considerations beyond my own.
>
> diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
> index acc71a26733f..67591428ad23 100644
> --- a/drivers/nvme/target/tcp.c
> +++ b/drivers/nvme/target/tcp.c
> @@ -120,7 +120,6 @@ struct nvmet_tcp_cmd {
>   	u32				pdu_len;
>   	u32				pdu_recv;
>   	int				sg_idx;
> -	char				recv_cbuf[CMSG_LEN(sizeof(char))];
>   	struct msghdr			recv_msg;
>   	struct bio_vec			*iov;
>   	u32				flags;
> @@ -1189,6 +1188,7 @@ static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
>   	if (unlikely(len < 0))
>   		return len;
>   	if (queue->tls_pskid) {
> +		iov_iter_revert(&msg.msg_iter, len);
>   		ret = nvmet_tcp_tls_record_ok(queue, &msg, cbuf);
>   		if (ret < 0)
>   			return ret;
> @@ -1245,19 +1245,22 @@ static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
>   static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
>   {
>   	struct nvmet_tcp_cmd  *cmd = queue->cmd;
> -	int len, ret;
> +	int len;
>   
>   	while (msg_data_left(&cmd->recv_msg)) {
>   		len = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
>   			cmd->recv_msg.msg_flags);
> +		if (queue->tls_pskid &&
> +		    (cmd->recv_msg.msg_flags & MSG_CTRUNC)) {
> +			cmd->recv_msg.msg_flags &= ~(MSG_CTRUNC | MSG_EOR);
> +			if (len == 0 || len == -EIO) {
> +				pr_err("queue %d: unexpected TLS control message while receiving data\n",
> +				       queue->idx);
> +				return -EIO;
> +			}
> +		}
>   		if (len <= 0)
>   			return len;
> -		if (queue->tls_pskid) {
> -			ret = nvmet_tcp_tls_record_ok(cmd->queue,
> -					&cmd->recv_msg, cmd->recv_cbuf);
> -			if (ret < 0)
> -				return ret;
> -		}
>   
>   		cmd->pdu_recv += len;
>   		cmd->rbytes_done += len;
> @@ -1295,6 +1298,7 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
>   	if (unlikely(len < 0))
>   		return len;
>   	if (queue->tls_pskid) {
> +		iov_iter_revert(&msg.msg_iter, len);
>   		ret = nvmet_tcp_tls_record_ok(queue, &msg, cbuf);
>   		if (ret < 0)
>   			return ret;
> @@ -1481,10 +1485,6 @@ static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
>   	if (!c->r2t_pdu)
>   		goto out_free_data;
>   
> -	if (queue->state == NVMET_TCP_Q_TLS_HANDSHAKE) {
> -		c->recv_msg.msg_control = c->recv_cbuf;
> -		c->recv_msg.msg_controllen = sizeof(c->recv_cbuf);
> -	}
>   	c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
>   
>   	list_add_tail(&c->entry, &queue->free_list);
> @@ -1764,6 +1764,7 @@ static int nvmet_tcp_try_peek_pdu(struct nvmet_tcp_queue *queue)
>   		return len;
>   	}
>   
> +	iov_iter_revert(&msg.msg_iter, len);
>   	ret = nvmet_tcp_tls_record_ok(queue, &msg, cbuf);
>   	if (ret < 0)
>   		return ret;

Hannes,

can you look at the tls code and provide an input ?

-ck