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

[elad.grupi at dell.com]

From: Elad Grupi <elad.grupi at 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.

Signed-off-by: Elad Grupi <elad.grupi at dell.com>
---
 drivers/nvme/target/tcp.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index d535080b781f..f181744b0214 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -146,6 +146,7 @@ static struct workqueue_struct *nvmet_tcp_wq;
 static struct nvmet_fabrics_ops nvmet_tcp_ops;
 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
+static void nvmet_tcp_queue_response(struct nvmet_req *req);
 
 static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
 		struct nvmet_tcp_cmd *cmd)
@@ -476,7 +477,15 @@ static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
 		nvmet_setup_c2h_data_pdu(queue->snd_cmd);
 	else if (nvmet_tcp_need_data_in(queue->snd_cmd))
 		nvmet_setup_r2t_pdu(queue->snd_cmd);
-	else
+	else if (nvmet_tcp_has_data_in(queue->snd_cmd) &&
+			nvmet_tcp_has_inline_data(queue->snd_cmd)) {
+		/*
+		 * wait for inline data before processing the response
+		 * so the iov will not be freed
+		 */
+		nvmet_tcp_queue_response(&queue->snd_cmd->req);
+		queue->snd_cmd = NULL;
+	} else
 		nvmet_setup_response_pdu(queue->snd_cmd);
 
 	return queue->snd_cmd;
-- 
2.16.5