FAILED: patch "[PATCH] nvme-auth: fail when the controller does not authenticate itself" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] nvme-auth: fail when the controller does not authenticate itself" failed to apply to 6.6-stable tree

[Sasha Levin]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x f9e43d924bc74feeb56197de82b2845de2a4b85a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107053428-failed-6.6-f9e43d924bc7@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From f9e43d924bc74feeb56197de82b2845de2a4b85a Mon Sep 17 00:00:00 2001
From: Yehyeong Lee <yhlee@isslab.korea.ac.kr>
Date: Tue, 6 Oct 2026 22:48:05 +0900
Subject: [PATCH] nvme-auth: fail when the controller does not authenticate
 itself

nvme_auth_process_dhchap_success1() returns success as soon as the
controller clears the rvalid flag in its DH-HMAC-CHAP success1 message,
without looking at whether the host had asked the controller to
authenticate.  A host configured with a controller secret sends a
challenge in its reply, computes the expected controller response, and
sets chap->bi_directional; if the controller then answers with
rvalid = 0 the response is never compared, the host still sends
success2, and the queue is marked as authenticated.

A malicious or man-in-the-middle controller therefore only has to clear
one flag to turn the configured bidirectional authentication into a
one-way one, without holding any secret of its own.  The target side
already treats the mirror image of this as fatal: when the host supplied
a challenge but no controller key is configured, nvmet_auth_success1()
fails the authentication rather than answering with rvalid = 0.

Refuse the connection if the controller returns no response although
bidirectional authentication was requested.  chap->bi_directional is the
right condition rather than ctrl->ctrl_key, because secure concatenation
sends a challenge only to derive the PSK and deliberately clears
bi_directional; a one-way setup without a controller secret keeps
returning success as before.

Fixes: f50fff73d620 ("nvme: implement In-Band authentication")
Cc: stable@vger.kernel.org
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yehyeong Lee <yhlee@isslab.korea.ac.kr>
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 drivers/nvme/host/auth.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index e55920642f2c1..cbb38935fa227 100644
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -358,8 +358,21 @@ static int nvme_auth_process_dhchap_success1(struct nvme_ctrl *ctrl,
 			 nvme_auth_hmac_name(chap->hash_id),
 			 nvme_auth_dhgroup_name(chap->dhgroup_id));
 
-	if (!data->rvalid)
+	if (!data->rvalid) {
+		/*
+		 * The controller did not return a response.  If we asked it to
+		 * authenticate itself the session must not be used, otherwise
+		 * mutual authentication would silently degrade to one-way.
+		 */
+		if (chap->bi_directional) {
+			dev_warn(ctrl->device,
+				 "qid %d: controller did not authenticate\n",
+				 chap->qid);
+			chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
+			return -ECONNREFUSED;
+		}
 		return 0;
+	}
 
 	/* Validate controller response */
 	if (crypto_memneq(chap->response, data->rval, data->hl)) {
-- 
2.53.0

[PATCH 6.6.y 1/2] nvme-auth: add flag for bi-directional auth

[Sasha Levin]

From: Mark O'Donovan <shiftee@posteo.net>

[ Upstream commit fc1e03eacac8e5ff8664ce2ebadabba8604f09f4 ]

Introduces an explicit variable for bi-directional auth.
The currently used variable chap->s2 is incorrectly zeroed for
uni-directional auth. That will be fixed in the next patch so this
needs to change to avoid sending unexpected success2 messages

Signed-off-by: Mark O'Donovan <shiftee@posteo.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Stable-dep-of: f9e43d924bc7 ("nvme-auth: fail when the controller does not authenticate itself")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/auth.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index 9f2a6472802e7..6903c1a4e7692 100644
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -29,6 +29,7 @@ struct nvme_dhchap_queue_context {
 	int error;
 	u32 s1;
 	u32 s2;
+	bool bi_directional;
 	u16 transaction;
 	u8 status;
 	u8 dhgroup_id;
@@ -313,6 +314,7 @@ static int nvme_auth_set_dhchap_reply_data(struct nvme_ctrl *ctrl,
 	data->dhvlen = cpu_to_le16(chap->host_key_len);
 	memcpy(data->rval, chap->response, chap->hash_len);
 	if (ctrl->ctrl_key) {
+		chap->bi_directional = true;
 		get_random_bytes(chap->c2, chap->hash_len);
 		data->cvalid = 1;
 		chap->s2 = nvme_auth_get_seqnum();
@@ -664,6 +666,7 @@ static void nvme_auth_reset_dhchap(struct nvme_dhchap_queue_context *chap)
 	chap->error = 0;
 	chap->s1 = 0;
 	chap->s2 = 0;
+	chap->bi_directional = false;
 	chap->transaction = 0;
 	memset(chap->c1, 0, sizeof(chap->c1));
 	memset(chap->c2, 0, sizeof(chap->c2));
@@ -826,7 +829,7 @@ static void nvme_queue_auth_work(struct work_struct *work)
 		goto fail2;
 	}
 
-	if (chap->s2) {
+	if (chap->bi_directional) {
 		/* DH-HMAC-CHAP Step 5: send success2 */
 		dev_dbg(ctrl->device, "%s: qid %d send success2\n",
 			__func__, chap->qid);
-- 
2.53.0

[PATCH 6.6.y 2/2] nvme-auth: fail when the controller does not authenticate itself

[Sasha Levin]

From: Yehyeong Lee <yhlee@isslab.korea.ac.kr>

[ Upstream commit f9e43d924bc74feeb56197de82b2845de2a4b85a ]

nvme_auth_process_dhchap_success1() returns success as soon as the
controller clears the rvalid flag in its DH-HMAC-CHAP success1 message,
without looking at whether the host had asked the controller to
authenticate.  A host configured with a controller secret sends a
challenge in its reply, computes the expected controller response, and
sets chap->bi_directional; if the controller then answers with
rvalid = 0 the response is never compared, the host still sends
success2, and the queue is marked as authenticated.

A malicious or man-in-the-middle controller therefore only has to clear
one flag to turn the configured bidirectional authentication into a
one-way one, without holding any secret of its own.  The target side
already treats the mirror image of this as fatal: when the host supplied
a challenge but no controller key is configured, nvmet_auth_success1()
fails the authentication rather than answering with rvalid = 0.

Refuse the connection if the controller returns no response although
bidirectional authentication was requested.  chap->bi_directional is the
right condition rather than ctrl->ctrl_key, because secure concatenation
sends a challenge only to derive the PSK and deliberately clears
bi_directional; a one-way setup without a controller secret keeps
returning success as before.

Fixes: f50fff73d620 ("nvme: implement In-Band authentication")
Cc: stable@vger.kernel.org
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yehyeong Lee <yhlee@isslab.korea.ac.kr>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/auth.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index 6903c1a4e7692..03d05a71e6616 100644
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -367,8 +367,21 @@ static int nvme_auth_process_dhchap_success1(struct nvme_ctrl *ctrl,
 			 nvme_auth_hmac_name(chap->hash_id),
 			 nvme_auth_dhgroup_name(chap->dhgroup_id));
 
-	if (!data->rvalid)
+	if (!data->rvalid) {
+		/*
+		 * The controller did not return a response.  If we asked it to
+		 * authenticate itself the session must not be used, otherwise
+		 * mutual authentication would silently degrade to one-way.
+		 */
+		if (chap->bi_directional) {
+			dev_warn(ctrl->device,
+				 "qid %d: controller did not authenticate\n",
+				 chap->qid);
+			chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
+			return -ECONNREFUSED;
+		}
 		return 0;
+	}
 
 	/* Validate controller response */
 	if (crypto_memneq(chap->response, data->rval, data->hl)) {
-- 
2.53.0