From fd0823f405090f9f410fc3e3ff7efb52e7b486fa Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Mon, 15 Mar 2021 14:08:11 -0700 Subject: [PATCH] nvme-tcp: fix a NULL deref when receiving a 0-length r2t PDU When the controller sends us a 0-length r2t PDU we should not attempt to try to set up a h2cdata PDU but rather conclude that this is a buggy controller (forward progress is not possible) and simply fail it immediately. Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver") Reported-by: Belanger, Martin Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig --- 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 c535836e7065..5b23e1d52cb3 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -568,6 +568,13 @@ static int nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req, 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", -- 2.39.5