[PATCH] nvmet-auth: update sc_c in host response

[PATCH] nvmet-auth: update sc_c in host response

[Hannes Reinecke]

From: Hannes Reinecke <hare@suse.de>

The target code should set the sc_c bit in calculating the host response
based on the status of the 'concat' setting, otherwise we'll get an
authentication mismatch for hosts setting that bit correctly.

Fixes: 7e091add9c43 ("nvme-auth: update sc_c in host response")
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/target/auth.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c
index b340380f3892..ceba21684e82 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];
+	u8 buf[4], sc_c = ctrl->concat ? 1 : 0;
 	int ret;
 
 	hash_name = nvme_auth_hmac_name(ctrl->shash_id);
@@ -367,13 +367,14 @@ int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response,
 	ret = crypto_shash_update(shash, buf, 2);
 	if (ret)
 		goto out;
-	memset(buf, 0, 4);
+	*buf = sc_c;
 	ret = crypto_shash_update(shash, buf, 1);
 	if (ret)
 		goto out;
 	ret = crypto_shash_update(shash, "HostHost", 8);
 	if (ret)
 		goto out;
+	memset(buf, 0, 4);
 	ret = crypto_shash_update(shash, ctrl->hostnqn, strlen(ctrl->hostnqn));
 	if (ret)
 		goto out;
-- 
2.43.0

Re: [PATCH] nvmet-auth: update sc_c in host response

[Keith Busch]

On Wed, Oct 22, 2025 at 09:59:24AM +0200, Hannes Reinecke wrote:
> From: Hannes Reinecke <hare@suse.de>
> 
> The target code should set the sc_c bit in calculating the host response
> based on the status of the 'concat' setting, otherwise we'll get an
> authentication mismatch for hosts setting that bit correctly.

Thanks, applied to nvme-6.18.