[PATCH v3] nvmet-auth: update sc_c in target host hash calculation

[PATCH v3] nvmet-auth: update sc_c in target host hash calculation

[alistair23]

From: Alistair Francis <alistair.francis@wdc.com>

Commit 7e091add9c43 "nvme-auth: update sc_c in host response" added
the sc_c variable to the dhchap queue context structure which is
appropriately set during negotiate and then used in the host response.

This breaks secure concat connections with a Linux target as the target
code wasn't updated at the same time. This patch fixes this by adding a
new sc_c variable to the host hash calculations.

Fixes: 7e091add9c43 ("nvme-auth: update sc_c in host response")
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 drivers/nvme/target/auth.c             | 4 ++--
 drivers/nvme/target/fabrics-cmd-auth.c | 1 +
 drivers/nvme/target/nvmet.h            | 1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c
index 02c23998e13c..58d80fc72fda 100644
--- a/drivers/nvme/target/auth.c
+++ b/drivers/nvme/target/auth.c
@@ -298,7 +298,7 @@ int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response,
 	const char *hash_name;
 	u8 *challenge = req->sq->dhchap_c1;
 	struct nvme_dhchap_key *transformed_key;
-	u8 buf[4], sc_c = ctrl->concat ? 1 : 0;
+	u8 buf[4];
 	int ret;
 
 	hash_name = nvme_auth_hmac_name(ctrl->shash_id);
@@ -367,7 +367,7 @@ int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response,
 	ret = crypto_shash_update(shash, buf, 2);
 	if (ret)
 		goto out;
-	*buf = sc_c;
+	*buf = req->sq->sc_c;
 	ret = crypto_shash_update(shash, buf, 1);
 	if (ret)
 		goto out;
diff --git a/drivers/nvme/target/fabrics-cmd-auth.c b/drivers/nvme/target/fabrics-cmd-auth.c
index 5d7d913927d8..0cd722ebfa75 100644
--- a/drivers/nvme/target/fabrics-cmd-auth.c
+++ b/drivers/nvme/target/fabrics-cmd-auth.c
@@ -43,6 +43,7 @@ static u8 nvmet_auth_negotiate(struct nvmet_req *req, void *d)
 		 data->auth_protocol[0].dhchap.halen,
 		 data->auth_protocol[0].dhchap.dhlen);
 	req->sq->dhchap_tid = le16_to_cpu(data->t_id);
+	req->sq->sc_c = data->sc_c;
 	if (data->sc_c != NVME_AUTH_SECP_NOSC) {
 		if (!IS_ENABLED(CONFIG_NVME_TARGET_TCP_TLS))
 			return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 73da823a91fb..20be2fe43307 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -159,6 +159,7 @@ struct nvmet_sq {
 	bool			authenticated;
 	struct delayed_work	auth_expired_work;
 	u16			dhchap_tid;
+	u8			sc_c;
 	u8			dhchap_status;
 	u8			dhchap_step;
 	u8			*dhchap_c1;
-- 
2.51.1

Re: [PATCH v3] nvmet-auth: update sc_c in target host hash calculation

[Hannes Reinecke]

On 11/7/25 00:17, alistair23@gmail.com wrote:
> From: Alistair Francis <alistair.francis@wdc.com>
> 
> Commit 7e091add9c43 "nvme-auth: update sc_c in host response" added
> the sc_c variable to the dhchap queue context structure which is
> appropriately set during negotiate and then used in the host response.
> 
> This breaks secure concat connections with a Linux target as the target
> code wasn't updated at the same time. This patch fixes this by adding a
> new sc_c variable to the host hash calculations.
> 
> Fixes: 7e091add9c43 ("nvme-auth: update sc_c in host response")
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>   drivers/nvme/target/auth.c             | 4 ++--
>   drivers/nvme/target/fabrics-cmd-auth.c | 1 +
>   drivers/nvme/target/nvmet.h            | 1 +
>   3 files changed, 4 insertions(+), 2 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich

Re: [PATCH v3] nvmet-auth: update sc_c in target host hash calculation

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH v3] nvmet-auth: update sc_c in target host hash calculation

[Martin George]

On Fri, 2025-11-07 at 09:17 +1000, alistair23@gmail.com wrote:
> From: Alistair Francis <alistair.francis@wdc.com>
> 
> Commit 7e091add9c43 "nvme-auth: update sc_c in host response" added
> the sc_c variable to the dhchap queue context structure which is
> appropriately set during negotiate and then used in the host
> response.
> 
> This breaks secure concat connections with a Linux target as the
> target
> code wasn't updated at the same time. This patch fixes this by adding
> a
> new sc_c variable to the host hash calculations.
> 
> Fixes: 7e091add9c43 ("nvme-auth: update sc_c in host response")
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  drivers/nvme/target/auth.c             | 4 ++--
>  drivers/nvme/target/fabrics-cmd-auth.c | 1 +
>  drivers/nvme/target/nvmet.h            | 1 +
>  3 files changed, 4 insertions(+), 2 deletions(-)

Reviewed-by: Martin George <marting@netapp.com>

-Martin

Re: [PATCH v3] nvmet-auth: update sc_c in target host hash calculation

[Alistair Francis]

On Fri, Nov 7, 2025 at 9:17 AM <alistair23@gmail.com> wrote:
>
> From: Alistair Francis <alistair.francis@wdc.com>
>
> Commit 7e091add9c43 "nvme-auth: update sc_c in host response" added
> the sc_c variable to the dhchap queue context structure which is
> appropriately set during negotiate and then used in the host response.
>
> This breaks secure concat connections with a Linux target as the target
> code wasn't updated at the same time. This patch fixes this by adding a
> new sc_c variable to the host hash calculations.
>
> Fixes: 7e091add9c43 ("nvme-auth: update sc_c in host response")
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Gentle reminder that this is needed in 6.18

Alistair

Re: [PATCH v3] nvmet-auth: update sc_c in target host hash calculation

[Shinichiro Kawasaki]

On Nov 07, 2025 / 09:17, alistair23@gmail.com wrote:
> From: Alistair Francis <alistair.francis@wdc.com>
> 
> Commit 7e091add9c43 "nvme-auth: update sc_c in host response" added
> the sc_c variable to the dhchap queue context structure which is
> appropriately set during negotiate and then used in the host response.
> 
> This breaks secure concat connections with a Linux target as the target
> code wasn't updated at the same time. This patch fixes this by adding a
> new sc_c variable to the host hash calculations.
> 
> Fixes: 7e091add9c43 ("nvme-auth: update sc_c in host response")
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

I confirmed that this patch avoids the blktests nvme/063 failure symptom
that I reported [*]. Thanks for the fix.

Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>

[*] https://lore.kernel.org/linux-nvme/6xoxbezgcnv4bfaevi3pdpesfelia3epxiddk47azho7y5mnhr@ykmlqgnrbl3w/

Re: [PATCH v3] nvmet-auth: update sc_c in target host hash calculation

[Keith Busch]

On Fri, Nov 07, 2025 at 09:17:11AM +1000, alistair23@gmail.com wrote:
> From: Alistair Francis <alistair.francis@wdc.com>
> 
> Commit 7e091add9c43 "nvme-auth: update sc_c in host response" added
> the sc_c variable to the dhchap queue context structure which is
> appropriately set during negotiate and then used in the host response.
> 
> This breaks secure concat connections with a Linux target as the target
> code wasn't updated at the same time. This patch fixes this by adding a
> new sc_c variable to the host hash calculations.

Thanks, applied to nvme-6.18.