[PATCH 5.1 96/98] nvme-tcp: fix possible null deref on a timed out io queue connect

[Greg Kroah-Hartman]

From: Sagi Grimberg <sagi@xxxxxxxxxxx>

commit f34e25898a608380a60135288019c4cb6013bec8 upstream.

If I/O queue connect times out, we might have freed the queue socket
already, so check for that on the error path in nvme_tcp_start_queue.

Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/nvme/host/tcp.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1423,7 +1423,8 @@ static int nvme_tcp_start_queue(struct n
 	if (!ret) {
 		set_bit(NVME_TCP_Q_LIVE, &ctrl->queues[idx].flags);
 	} else {
-		__nvme_tcp_stop_queue(&ctrl->queues[idx]);
+		if (test_bit(NVME_TCP_Q_ALLOCATED, &ctrl->queues[idx].flags))
+			__nvme_tcp_stop_queue(&ctrl->queues[idx]);
 		dev_err(nctrl->device,
 			"failed to connect queue: %d ret=%d\n", idx, ret);
 	}