[PATCH v2] nvme/tcp: handle rejected keys for secure concatenation

[Alistair Francis]

On Tue, 2026-05-12 at 09:45 +1000, Wilfred Mallawa wrote:
> From: Wilfred Mallawa <wilfred.mallawa at wdc.com>
> 
> The NVMe-TCP specification [1] states that if the PSK retained or
> generated is not available on the subsystem, the TLS 1.3 handshake
> shall
> be aborted with an unknown_psk_identity alert and the connection be
> closed.
> 
> Currently, when an unknown_psk_identity alert is sent from an
> endpoint,
> tlshd returns EACCES as the TLS error. On subsequent reconnection
> attempts, we fail with the same error because we keep attempting to
> connect with a stale key. This may occur if the endpoint experienced
> a
> full reset and lost its PSK.
> 
> With support in tlshd to return -EKEYREJECTED when an
> unknown_psk_identity
> alert is received [2], the kernel can now detect this condition and
> revoke
> the current tls_key. This allows the subsequent reconnect to perform
> re-authentication via DHCHAP to generate a fresh PSK.
> 
> [1]
> https://nvmexpress.org/wp-content/uploads/NVM-Express-TCP-Transport-Specification-Revision-1.1-2024.08.05-Ratified.pdf
> [2] https://github.com/oracle/ktls-utils/pull/149
> 
> Signed-off-by: Wilfred Mallawa <wilfred.mallawa at wdc.com>

Reviewed-by: Alistair Francis <alistair.francis at wdc.com>

Alistair

> ---
> V1 -> V2:
> 	- Typo in commit message
> 	- Re-worded the comment in code
> 	- Added reference to ktls-utils PR (merged) for userspace
> changes
> ---
>  drivers/nvme/host/tcp.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index 15d36d6a728e..8e5421d2e8b9 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -1767,6 +1767,17 @@ static int nvme_tcp_start_tls(struct nvme_ctrl
> *nctrl,
>  			dev_err(nctrl->device,
>  				"queue %d: TLS handshake complete,
> error %d\n",
>  				qid, queue->tls_err);
> +
> +			/*
> +			 * If the key is stale, revoke it such that
> on a
> +			 * subsequent reconnect, we will generate a
> new PSK.
> +			 */
> +			if (queue->tls_err == EKEYREJECTED && qid ==
> 0 &&
> +			    nctrl->opts->concat && nctrl->opts-
> >tls_key) {
> +				nvme_auth_revoke_tls_key(nctrl);
> +				dev_warn(nctrl->device,
> +					 "qid 0: revoking stale
> key\n");
> +			}
>  		} else {
>  			dev_dbg(nctrl->device,
>  				"queue %d: TLS handshake
> complete\n", qid);