[PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error

[PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error

[elad.grupi]

From: Elad Grupi <elad.grupi@dell.com>

In case there is an io that contains inline data and it goes to
parsing error flow, command response will free command and iov
before clearing the data on the socket buffer.
This will delay the command response until receive flow is completed.

Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver")
Signed-off-by: Elad Grupi <elad.grupi@dell.com>
---
 drivers/nvme/target/tcp.c | 37 ++++++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 70cc507d1565..d159ff426630 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -38,7 +38,8 @@ enum nvmet_tcp_send_state {
 	NVMET_TCP_SEND_DATA,
 	NVMET_TCP_SEND_R2T,
 	NVMET_TCP_SEND_DDGST,
-	NVMET_TCP_SEND_RESPONSE
+	NVMET_TCP_SEND_RESPONSE,
+	NVMET_TCP_SEND_POSTPONED
 };
 
 enum nvmet_tcp_recv_state {
@@ -530,6 +531,14 @@ static void nvmet_tcp_queue_response(struct nvmet_req *req)
 	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);
 }
 
+static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd)
+{
+	if (unlikely(cmd->state == NVMET_TCP_SEND_POSTPONED))
+		nvmet_tcp_queue_response(&cmd->req);
+	else
+		cmd->req.execute(&cmd->req);
+}
+
 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
 {
 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
@@ -702,6 +711,18 @@ static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
 			return 0;
 	}
 
+	if (unlikely((cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
+			nvmet_tcp_has_data_in(cmd) &&
+			nvmet_tcp_has_inline_data(cmd))) {
+		/*
+		 * wait for inline data before processing the response
+		 * so the iov will not be freed
+		 */
+		cmd->state = NVMET_TCP_SEND_POSTPONED;
+		queue->snd_cmd = NULL;
+		goto done_send;
+	}
+
 	if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
 		ret = nvmet_try_send_data_pdu(cmd);
 		if (ret <= 0)
@@ -960,7 +981,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
 
 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
-		return -EAGAIN;
+		return 0;
 	}
 
 	ret = nvmet_tcp_map_data(queue->cmd);
@@ -1103,10 +1124,8 @@ static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
 		return 0;
 	}
 
-	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
-	    cmd->rbytes_done == cmd->req.transfer_len) {
-		cmd->req.execute(&cmd->req);
-	}
+	if (cmd->rbytes_done == cmd->req.transfer_len)
+		nvmet_tcp_execute_request(cmd);
 
 	nvmet_prepare_receive_pdu(queue);
 	return 0;
@@ -1143,9 +1162,9 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
 		goto out;
 	}
 
-	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
-	    cmd->rbytes_done == cmd->req.transfer_len)
-		cmd->req.execute(&cmd->req);
+	if (cmd->rbytes_done == cmd->req.transfer_len)
+		nvmet_tcp_execute_request(cmd);
+
 	ret = 0;
 out:
 	nvmet_prepare_receive_pdu(queue);
-- 
2.18.2


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Re: [PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error

[Hou Pu]

On Tue, 30 Mar 2021 20:24:07 +0300, Elad wrote:
> @@ -960,7 +981,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
>  			le32_to_cpu(req->cmd->common.dptr.sgl.length));
> 
>  		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
> -		return -EAGAIN;
> +		return 0;
>  	}
> 
>  	ret = nvmet_tcp_map_data(queue->cmd);

Hi Elad
By returning 0, the response is queued twice before it is get off from the
list. Even still returning -EAGAIN, the cmd still could be queued twice
potentially.

I think we'd better not queue the failed cmd in first place.
Please see my following fix later.

Thanks,
Hou

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RE: [PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error

[Grupi, Elad]

Not sure I'm following.

Once req_init is failed, nvmet_tcp_handle_req_failure is called and changes the state to NVMET_TCP_RECV_DATA.
In state NVMET_TCP_RECV_DATA we should not queue the response before it is get off from the list.

Am I missing something here?

-----Original Message-----
From: Hou Pu <houpu.main@gmail.com> 
Sent: Wednesday, 31 March 2021 10:49
To: Grupi, Elad
Cc: linux-nvme@lists.infradead.org; sagi@grimberg.me
Subject: Re: [PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error


[EXTERNAL EMAIL] 

On Tue, 30 Mar 2021 20:24:07 +0300, Elad wrote:
> @@ -960,7 +981,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
>  			le32_to_cpu(req->cmd->common.dptr.sgl.length));
> 
>  		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
> -		return -EAGAIN;
> +		return 0;
>  	}
> 
>  	ret = nvmet_tcp_map_data(queue->cmd);

Hi Elad
By returning 0, the response is queued twice before it is get off from the list. Even still returning -EAGAIN, the cmd still could be queued twice potentially.

I think we'd better not queue the failed cmd in first place.
Please see my following fix later.

Thanks,
Hou
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Re: [PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error

[Hou Pu]

On Wed, 31 Mar 2021 08:28:46 +0000, Elad wrote:
> Not sure I'm following.
>
> Once req_init is failed, nvmet_tcp_handle_req_failure is called and changes the state to NVMET_TCP_RECV_DATA.
> In state NVMET_TCP_RECV_DATA we should not queue the response before it is get off from the list.
>
> Am I missing something here?

1. nvmet_tcp_handle_req_failure is called, 
2. Return 0 from nvmet_tcp_done_recv_pdu
3. nvmet_tcp_try_recv_data() from nvmet_tcp_try_recv_one(), After finish
   consume inline data, nvmet_tcp_execute_request() is called. Here
   NVMET_TCP_SEND_POSTPONED is not set. As nvmet_try_send_data_pdu()
   is not called yet. (it will be called after we return from
   nvmet_tcp_try_recv_one()).

Thanks,
Hou

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[PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error

[Hou Pu]

From: Elad Grupi <elad.grupi@dell.com>

In case there is an io that contains inline data and it goes to
parsing error flow, command response will free command and iov
before clearing the data on the socket buffer.
This will delay the command response until receive flow is completed.

Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver")
Signed-off-by: Elad Grupi <elad.grupi@dell.com>
Signed-off-by: Hou Pu <houpu.main@gmail.com>
---
 drivers/nvme/target/tcp.c | 39 +++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index d658c6e8263a..0759eef3f4da 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -525,11 +525,36 @@ static void nvmet_tcp_queue_response(struct nvmet_req *req)
 	struct nvmet_tcp_cmd *cmd =
 		container_of(req, struct nvmet_tcp_cmd, req);
 	struct nvmet_tcp_queue	*queue = cmd->queue;
+	struct nvme_sgl_desc *sgl;
+	u32 len;
+
+	if (unlikely(cmd == queue->cmd)) {
+		sgl = &cmd->req.cmd->common.dptr.sgl;
+		len = le32_to_cpu(sgl->length);
+
+		/*
+		 * Wait for inline data before processing the response.
+		 * Avoid using helpers, this might happen before
+		 * nvmet_req_init is completed.
+		 */
+		if (queue->rcv_state == NVMET_TCP_RECV_PDU &&
+		    len && len < cmd->req.port->inline_data_size &&
+		    nvme_is_write(cmd->req.cmd))
+			return;
+	}
 
 	llist_add(&cmd->lentry, &queue->resp_list);
 	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);
 }
 
+static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd)
+{
+	if (unlikely(cmd->flags & NVMET_TCP_F_INIT_FAILED))
+		nvmet_tcp_queue_response(&cmd->req);
+	else
+		cmd->req.execute(&cmd->req);
+}
+
 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
 {
 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
@@ -961,7 +986,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
 
 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
-		return -EAGAIN;
+		return 0;
 	}
 
 	ret = nvmet_tcp_map_data(queue->cmd);
@@ -1104,10 +1129,8 @@ static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
 		return 0;
 	}
 
-	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
-	    cmd->rbytes_done == cmd->req.transfer_len) {
-		cmd->req.execute(&cmd->req);
-	}
+	if (cmd->rbytes_done == cmd->req.transfer_len)
+		nvmet_tcp_execute_request(cmd);
 
 	nvmet_prepare_receive_pdu(queue);
 	return 0;
@@ -1144,9 +1167,9 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
 		goto out;
 	}
 
-	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
-	    cmd->rbytes_done == cmd->req.transfer_len)
-		cmd->req.execute(&cmd->req);
+	if (cmd->rbytes_done == cmd->req.transfer_len)
+		nvmet_tcp_execute_request(cmd);
+
 	ret = 0;
 out:
 	nvmet_prepare_receive_pdu(queue);
-- 
2.28.0


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RE: [PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error

[Grupi, Elad]

Right. Thank you for the clarification.

Elad

-----Original Message-----
From: Hou Pu <houpu.main@gmail.com> 
Sent: Wednesday, 31 March 2021 12:08
To: Grupi, Elad
Cc: houpu.main@gmail.com; linux-nvme@lists.infradead.org; sagi@grimberg.me
Subject: Re: [PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error


[EXTERNAL EMAIL] 

On Wed, 31 Mar 2021 08:28:46 +0000, Elad wrote:
> Not sure I'm following.
>
> Once req_init is failed, nvmet_tcp_handle_req_failure is called and changes the state to NVMET_TCP_RECV_DATA.
> In state NVMET_TCP_RECV_DATA we should not queue the response before it is get off from the list.
>
> Am I missing something here?

1. nvmet_tcp_handle_req_failure is called, 2. Return 0 from nvmet_tcp_done_recv_pdu 3. nvmet_tcp_try_recv_data() from nvmet_tcp_try_recv_one(), After finish
   consume inline data, nvmet_tcp_execute_request() is called. Here
   NVMET_TCP_SEND_POSTPONED is not set. As nvmet_try_send_data_pdu()
   is not called yet. (it will be called after we return from
   nvmet_tcp_try_recv_one()).

Thanks,
Hou
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RE: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error

[Grupi, Elad]

Looks good to me.

Thanks,
Elad

-----Original Message-----
From: Hou Pu <houpu.main@gmail.com> 
Sent: Wednesday, 31 March 2021 12:13
To: houpu.main@gmail.com; Grupi, Elad
Cc: linux-nvme@lists.infradead.org; sagi@grimberg.me
Subject: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error


[EXTERNAL EMAIL] 

From: Elad Grupi <elad.grupi@dell.com>

In case there is an io that contains inline data and it goes to parsing error flow, command response will free command and iov before clearing the data on the socket buffer.
This will delay the command response until receive flow is completed.

Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver")
Signed-off-by: Elad Grupi <elad.grupi@dell.com>
Signed-off-by: Hou Pu <houpu.main@gmail.com>
---
 drivers/nvme/target/tcp.c | 39 +++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index d658c6e8263a..0759eef3f4da 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -525,11 +525,36 @@ static void nvmet_tcp_queue_response(struct nvmet_req *req)
 	struct nvmet_tcp_cmd *cmd =
 		container_of(req, struct nvmet_tcp_cmd, req);
 	struct nvmet_tcp_queue	*queue = cmd->queue;
+	struct nvme_sgl_desc *sgl;
+	u32 len;
+
+	if (unlikely(cmd == queue->cmd)) {
+		sgl = &cmd->req.cmd->common.dptr.sgl;
+		len = le32_to_cpu(sgl->length);
+
+		/*
+		 * Wait for inline data before processing the response.
+		 * Avoid using helpers, this might happen before
+		 * nvmet_req_init is completed.
+		 */
+		if (queue->rcv_state == NVMET_TCP_RECV_PDU &&
+		    len && len < cmd->req.port->inline_data_size &&
+		    nvme_is_write(cmd->req.cmd))
+			return;
+	}
 
 	llist_add(&cmd->lentry, &queue->resp_list);
 	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);  }
 
+static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd) {
+	if (unlikely(cmd->flags & NVMET_TCP_F_INIT_FAILED))
+		nvmet_tcp_queue_response(&cmd->req);
+	else
+		cmd->req.execute(&cmd->req);
+}
+
 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)  {
 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue); @@ -961,7 +986,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
 
 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
-		return -EAGAIN;
+		return 0;
 	}
 
 	ret = nvmet_tcp_map_data(queue->cmd);
@@ -1104,10 +1129,8 @@ static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
 		return 0;
 	}
 
-	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
-	    cmd->rbytes_done == cmd->req.transfer_len) {
-		cmd->req.execute(&cmd->req);
-	}
+	if (cmd->rbytes_done == cmd->req.transfer_len)
+		nvmet_tcp_execute_request(cmd);
 
 	nvmet_prepare_receive_pdu(queue);
 	return 0;
@@ -1144,9 +1167,9 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
 		goto out;
 	}
 
-	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
-	    cmd->rbytes_done == cmd->req.transfer_len)
-		cmd->req.execute(&cmd->req);
+	if (cmd->rbytes_done == cmd->req.transfer_len)
+		nvmet_tcp_execute_request(cmd);
+
 	ret = 0;
 out:
 	nvmet_prepare_receive_pdu(queue);
--
2.28.0

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Re: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error

[Christoph Hellwig]

On Wed, Mar 31, 2021 at 01:27:40PM +0000, Grupi, Elad wrote:
> Looks good to me.

Is that a Reviewed-by?

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RE: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error

[Grupi, Elad]

Let's have @sagi@grimberg.me take another look please.

Thanks,
Elad

-----Original Message-----
From: Christoph Hellwig <hch@infradead.org> 
Sent: Friday, 2 April 2021 19:18
To: Grupi, Elad
Cc: Hou Pu; linux-nvme@lists.infradead.org; sagi@grimberg.me
Subject: Re: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error


[EXTERNAL EMAIL] 

On Wed, Mar 31, 2021 at 01:27:40PM +0000, Grupi, Elad wrote:
> Looks good to me.

Is that a Reviewed-by?
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RE: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error

[Grupi, Elad]

Hi Hou.

I tested this patch on our system and it solved the issue.

I think there is a minor issue with the spaces indentation in the patch:
+		    len && len < cmd->req.port->inline_data_size &&
+		    nvme_is_write(cmd->req.cmd))

Thanks,
Elad

-----Original Message-----
From: Hou Pu <houpu.main@gmail.com> 
Sent: Wednesday, 31 March 2021 12:13
To: houpu.main@gmail.com; Grupi, Elad
Cc: linux-nvme@lists.infradead.org; sagi@grimberg.me
Subject: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error


[EXTERNAL EMAIL] 

From: Elad Grupi <elad.grupi@dell.com>

In case there is an io that contains inline data and it goes to parsing error flow, command response will free command and iov before clearing the data on the socket buffer.
This will delay the command response until receive flow is completed.

Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver")
Signed-off-by: Elad Grupi <elad.grupi@dell.com>
Signed-off-by: Hou Pu <houpu.main@gmail.com>
---
 drivers/nvme/target/tcp.c | 39 +++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index d658c6e8263a..0759eef3f4da 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -525,11 +525,36 @@ static void nvmet_tcp_queue_response(struct nvmet_req *req)
 	struct nvmet_tcp_cmd *cmd =
 		container_of(req, struct nvmet_tcp_cmd, req);
 	struct nvmet_tcp_queue	*queue = cmd->queue;
+	struct nvme_sgl_desc *sgl;
+	u32 len;
+
+	if (unlikely(cmd == queue->cmd)) {
+		sgl = &cmd->req.cmd->common.dptr.sgl;
+		len = le32_to_cpu(sgl->length);
+
+		/*
+		 * Wait for inline data before processing the response.
+		 * Avoid using helpers, this might happen before
+		 * nvmet_req_init is completed.
+		 */
+		if (queue->rcv_state == NVMET_TCP_RECV_PDU &&
+		    len && len < cmd->req.port->inline_data_size &&
+		    nvme_is_write(cmd->req.cmd))
+			return;
+	}
 
 	llist_add(&cmd->lentry, &queue->resp_list);
 	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);  }
 
+static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd) {
+	if (unlikely(cmd->flags & NVMET_TCP_F_INIT_FAILED))
+		nvmet_tcp_queue_response(&cmd->req);
+	else
+		cmd->req.execute(&cmd->req);
+}
+
 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)  {
 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue); @@ -961,7 +986,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
 
 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
-		return -EAGAIN;
+		return 0;
 	}
 
 	ret = nvmet_tcp_map_data(queue->cmd);
@@ -1104,10 +1129,8 @@ static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
 		return 0;
 	}
 
-	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
-	    cmd->rbytes_done == cmd->req.transfer_len) {
-		cmd->req.execute(&cmd->req);
-	}
+	if (cmd->rbytes_done == cmd->req.transfer_len)
+		nvmet_tcp_execute_request(cmd);
 
 	nvmet_prepare_receive_pdu(queue);
 	return 0;
@@ -1144,9 +1167,9 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
 		goto out;
 	}
 
-	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
-	    cmd->rbytes_done == cmd->req.transfer_len)
-		cmd->req.execute(&cmd->req);
+	if (cmd->rbytes_done == cmd->req.transfer_len)
+		nvmet_tcp_execute_request(cmd);
+
 	ret = 0;
 out:
 	nvmet_prepare_receive_pdu(queue);
--
2.28.0

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Re: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error

[Hou Pu]

On Tue, Apr 6, 2021 at 3:03 AM Grupi, Elad <Elad.Grupi@dell.com> wrote:
>
> Hi Hou.
>
> I tested this patch on our system and it solved the issue.

Thanks.

>
> I think there is a minor issue with the spaces indentation in the patch:
> +                   len && len < cmd->req.port->inline_data_size &&
> +                   nvme_is_write(cmd->req.cmd))

Hi Elad,
I run scripts/checkpatch.pl, there are no errors or warnings.
We could find such indentation style in many places in tcp.c
or other files.

Thanks,
Hou


>
> Thanks,
> Elad
>
> -----Original Message-----
> From: Hou Pu <houpu.main@gmail.com>
> Sent: Wednesday, 31 March 2021 12:13
> To: houpu.main@gmail.com; Grupi, Elad
> Cc: linux-nvme@lists.infradead.org; sagi@grimberg.me
> Subject: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error
>
>
> [EXTERNAL EMAIL]
>
> From: Elad Grupi <elad.grupi@dell.com>
>
> In case there is an io that contains inline data and it goes to parsing error flow, command response will free command and iov before clearing the data on the socket buffer.
> This will delay the command response until receive flow is completed.
>
> Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver")
> Signed-off-by: Elad Grupi <elad.grupi@dell.com>
> Signed-off-by: Hou Pu <houpu.main@gmail.com>
> ---
>  drivers/nvme/target/tcp.c | 39 +++++++++++++++++++++++++++++++--------
>  1 file changed, 31 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index d658c6e8263a..0759eef3f4da 100644
> --- a/drivers/nvme/target/tcp.c
> +++ b/drivers/nvme/target/tcp.c
> @@ -525,11 +525,36 @@ static void nvmet_tcp_queue_response(struct nvmet_req *req)
>         struct nvmet_tcp_cmd *cmd =
>                 container_of(req, struct nvmet_tcp_cmd, req);
>         struct nvmet_tcp_queue  *queue = cmd->queue;
> +       struct nvme_sgl_desc *sgl;
> +       u32 len;
> +
> +       if (unlikely(cmd == queue->cmd)) {
> +               sgl = &cmd->req.cmd->common.dptr.sgl;
> +               len = le32_to_cpu(sgl->length);
> +
> +               /*
> +                * Wait for inline data before processing the response.
> +                * Avoid using helpers, this might happen before
> +                * nvmet_req_init is completed.
> +                */
> +               if (queue->rcv_state == NVMET_TCP_RECV_PDU &&
> +                   len && len < cmd->req.port->inline_data_size &&
> +                   nvme_is_write(cmd->req.cmd))
> +                       return;
> +       }
>
>         llist_add(&cmd->lentry, &queue->resp_list);
>         queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);  }
>
> +static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd) {
> +       if (unlikely(cmd->flags & NVMET_TCP_F_INIT_FAILED))
> +               nvmet_tcp_queue_response(&cmd->req);
> +       else
> +               cmd->req.execute(&cmd->req);
> +}
> +
>  static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)  {
>         u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue); @@ -961,7 +986,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
>                         le32_to_cpu(req->cmd->common.dptr.sgl.length));
>
>                 nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
> -               return -EAGAIN;
> +               return 0;
>         }
>
>         ret = nvmet_tcp_map_data(queue->cmd);
> @@ -1104,10 +1129,8 @@ static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
>                 return 0;
>         }
>
> -       if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
> -           cmd->rbytes_done == cmd->req.transfer_len) {
> -               cmd->req.execute(&cmd->req);
> -       }
> +       if (cmd->rbytes_done == cmd->req.transfer_len)
> +               nvmet_tcp_execute_request(cmd);
>
>         nvmet_prepare_receive_pdu(queue);
>         return 0;
> @@ -1144,9 +1167,9 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
>                 goto out;
>         }
>
> -       if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
> -           cmd->rbytes_done == cmd->req.transfer_len)
> -               cmd->req.execute(&cmd->req);
> +       if (cmd->rbytes_done == cmd->req.transfer_len)
> +               nvmet_tcp_execute_request(cmd);
> +
>         ret = 0;
>  out:
>         nvmet_prepare_receive_pdu(queue);
> --
> 2.28.0
>

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Re: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error

[Sagi Grimberg]

> From: Elad Grupi <elad.grupi@dell.com>
> 
> In case there is an io that contains inline data and it goes to
> parsing error flow, command response will free command and iov
> before clearing the data on the socket buffer.
> This will delay the command response until receive flow is completed.
> 
> Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver")
> Signed-off-by: Elad Grupi <elad.grupi@dell.com>
> Signed-off-by: Hou Pu <houpu.main@gmail.com>

This looks fine to me:

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

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Re: [PATCH v5] nvmet-tcp: fix a segmentation fault during io parsing error

[Christoph Hellwig]

Thanks,

applied to nvme-5.13.

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