FAILED: patch "[PATCH] nvme-tcp: fix host memory disclosure on R2T for a read" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] nvme-tcp: fix host memory disclosure on R2T for a read" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 6efbc52237facda35d2d874fe1765bb4839275d8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090304-lazily-cauterize-57c7@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 6efbc52237facda35d2d874fe1765bb4839275d8 Mon Sep 17 00:00:00 2001
From: Yehyeong Lee <yhlee@isslab.korea.ac.kr>
Date: Wed, 29 Jul 2026 14:46:02 +0900
Subject: [PATCH] nvme-tcp: fix host memory disclosure on R2T for a read
 command

nvme_tcp_handle_r2t() does not check the direction of the request the
R2T refers to. A malicious controller can send an R2T for a READ and
the host will answer it: nvme_tcp_setup_h2c_data_pdu() builds the
H2CData header and nvme_tcp_try_send_data() sends the request's data
buffer. That buffer is the READ destination, so its contents go to the
controller.

The command then completes normally and nothing is logged.

Against a test controller that answers every READ with an R2T, a 4096
byte buffered read returned all 4096 bytes, split over two R2Ts. The
pages contained stale kernel data, including an array of struct page
pointers.

Reject an R2T for a request that is not a write.

Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver")
Cc: stable@vger.kernel.org
Signed-off-by: Yehyeong Lee <yhlee@isslab.korea.ac.kr>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 46c2acc6abe0..62c5e38f5207 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -779,6 +779,13 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
 	}
 	req = blk_mq_rq_to_pdu(rq);
 
+	if (unlikely(rq_data_dir(rq) != WRITE)) {
+		dev_err(queue->ctrl->ctrl.device,
+			"req %d unexpected r2t for a non-write command\n",
+			rq->tag);
+		return -EPROTO;
+	}
+
 	if (unlikely(!r2t_length)) {
 		dev_err(queue->ctrl->ctrl.device,
 			"req %d r2t len is %u, probably a bug...\n",

[PATCH 5.10.y 1/2] nvme-tcp: validate R2T PDU in nvme_tcp_handle_r2t()

[Sasha Levin]

From: Varun Prakash <varun@chelsio.com>

[ Upstream commit 1d3ef9c3a39e04be31155c27ebf80342350c3abf ]

If maxh2cdata < r2t_length then driver will form multiple
H2CData PDUs, validate R2T PDU in nvme_tcp_handle_r2t() to
reuse nvme_tcp_setup_h2c_data_pdu().

Also set req->state to NVME_TCP_SEND_H2C_PDU in
nvme_tcp_setup_h2c_data_pdu().

Signed-off-by: Varun Prakash <varun@chelsio.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Stable-dep-of: 6efbc52237fa ("nvme-tcp: fix host memory disclosure on R2T for a read command")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/host/tcp.c | 55 ++++++++++++++++++-----------------------
 1 file changed, 24 insertions(+), 31 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 7d9ebd4f7947b..01d42b854be2d 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -598,7 +598,7 @@ static int nvme_tcp_handle_comp(struct nvme_tcp_queue *queue,
 	return ret;
 }
 
-static int nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
+static void nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
 		struct nvme_tcp_r2t_pdu *pdu)
 {
 	struct nvme_tcp_data_pdu *data = req->pdu;
@@ -607,32 +607,11 @@ static int nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
 	u8 hdgst = nvme_tcp_hdgst_len(queue);
 	u8 ddgst = nvme_tcp_ddgst_len(queue);
 
+	req->state = NVME_TCP_SEND_H2C_PDU;
+	req->offset = 0;
 	req->pdu_len = le32_to_cpu(pdu->r2t_length);
 	req->pdu_sent = 0;
 
-	if (unlikely(!req->pdu_len)) {
-		dev_err(queue->ctrl->ctrl.device,
-			"req %d r2t len is %u, probably a bug...\n",
-			rq->tag, req->pdu_len);
-		return -EPROTO;
-	}
-
-	if (unlikely(req->data_sent + req->pdu_len > req->data_len)) {
-		dev_err(queue->ctrl->ctrl.device,
-			"req %d r2t len %u exceeded data len %u (%zu sent)\n",
-			rq->tag, req->pdu_len, req->data_len,
-			req->data_sent);
-		return -EPROTO;
-	}
-
-	if (unlikely(le32_to_cpu(pdu->r2t_offset) < req->data_sent)) {
-		dev_err(queue->ctrl->ctrl.device,
-			"req %d unexpected r2t offset %u (expected %zu)\n",
-			rq->tag, le32_to_cpu(pdu->r2t_offset),
-			req->data_sent);
-		return -EPROTO;
-	}
-
 	memset(data, 0, sizeof(*data));
 	data->hdr.type = nvme_tcp_h2c_data;
 	data->hdr.flags = NVME_TCP_F_DATA_LAST;
@@ -648,7 +627,6 @@ static int nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
 	data->command_id = nvme_cid(rq);
 	data->data_offset = pdu->r2t_offset;
 	data->data_length = cpu_to_le32(req->pdu_len);
-	return 0;
 }
 
 static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
@@ -656,7 +634,7 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
 {
 	struct nvme_tcp_request *req;
 	struct request *rq;
-	int ret;
+	u32 r2t_length = le32_to_cpu(pdu->r2t_length);
 
 	rq = nvme_find_rq(nvme_tcp_tagset(queue), pdu->command_id);
 	if (!rq) {
@@ -667,13 +645,28 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
 	}
 	req = blk_mq_rq_to_pdu(rq);
 
-	ret = nvme_tcp_setup_h2c_data_pdu(req, pdu);
-	if (unlikely(ret))
-		return ret;
+	if (unlikely(!r2t_length)) {
+		dev_err(queue->ctrl->ctrl.device,
+			"req %d r2t len is %u, probably a bug...\n",
+			rq->tag, r2t_length);
+		return -EPROTO;
+	}
 
-	req->state = NVME_TCP_SEND_H2C_PDU;
-	req->offset = 0;
+	if (unlikely(req->data_sent + r2t_length > req->data_len)) {
+		dev_err(queue->ctrl->ctrl.device,
+			"req %d r2t len %u exceeded data len %u (%zu sent)\n",
+			rq->tag, r2t_length, req->data_len, req->data_sent);
+		return -EPROTO;
+	}
+
+	if (unlikely(le32_to_cpu(pdu->r2t_offset) < req->data_sent)) {
+		dev_err(queue->ctrl->ctrl.device,
+			"req %d unexpected r2t offset %u (expected %zu)\n",
+			rq->tag, le32_to_cpu(pdu->r2t_offset), req->data_sent);
+		return -EPROTO;
+	}
 
+	nvme_tcp_setup_h2c_data_pdu(req, pdu);
 	nvme_tcp_queue_request(req, false, true);
 
 	return 0;
-- 
2.53.0

[PATCH 5.10.y 2/2] nvme-tcp: fix host memory disclosure on R2T for a read command

[Sasha Levin]

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

[ Upstream commit 6efbc52237facda35d2d874fe1765bb4839275d8 ]

nvme_tcp_handle_r2t() does not check the direction of the request the
R2T refers to. A malicious controller can send an R2T for a READ and
the host will answer it: nvme_tcp_setup_h2c_data_pdu() builds the
H2CData header and nvme_tcp_try_send_data() sends the request's data
buffer. That buffer is the READ destination, so its contents go to the
controller.

The command then completes normally and nothing is logged.

Against a test controller that answers every READ with an R2T, a 4096
byte buffered read returned all 4096 bytes, split over two R2Ts. The
pages contained stale kernel data, including an array of struct page
pointers.

Reject an R2T for a request that is not a write.

Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver")
Cc: stable@vger.kernel.org
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/tcp.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 01d42b854be2d..c9436767534a7 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -645,6 +645,13 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
 	}
 	req = blk_mq_rq_to_pdu(rq);
 
+	if (unlikely(rq_data_dir(rq) != WRITE)) {
+		dev_err(queue->ctrl->ctrl.device,
+			"req %d unexpected r2t for a non-write command\n",
+			rq->tag);
+		return -EPROTO;
+	}
+
 	if (unlikely(!r2t_length)) {
 		dev_err(queue->ctrl->ctrl.device,
 			"req %d r2t len is %u, probably a bug...\n",
-- 
2.53.0