nvme-tcp: fix connect failure on receiving partial ICResp PDU

[ Upstream commit 578539e0969028f711c34d9a4565931edfe1d730 ]

nvme_tcp_init_connection() attempts to receive an ICResp PDU but only
checks that the return value from recvmsg() is non-negative. If the
sender closes the TCP connection or sends fewer than 128 bytes, this
check will pass even though the full PDU wasn't received.

Ensure the full ICResp PDU is received by checking that recvmsg()
returns the expected 128 bytes.

Additionally set the MSG_WAITALL flag for recvmsg(), as a sender could
split the ICResp over multiple TCP frames. Without MSG_WAITALL,
recvmsg() could return prematurely with only part of the PDU.

Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver")
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 4162893d493954a4fe57291fa77ceeb02b870450..d7c193028e7c3626a234fe4525a4e06e1b63d60b 100644 (file)
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1449,11 +1449,14 @@ static int nvme_tcp_init_connection(struct nvme_tcp_queue *queue)
                msg.msg_control = cbuf;
                msg.msg_controllen = sizeof(cbuf);
        }
+       msg.msg_flags = MSG_WAITALL;
        ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
                        iov.iov_len, msg.msg_flags);
-       if (ret < 0) {
+       if (ret < sizeof(*icresp)) {
                pr_warn("queue %d: failed to receive icresp, error %d\n",
                        nvme_tcp_queue_id(queue), ret);
+               if (ret >= 0)
+                       ret = -ECONNRESET;
                goto free_icresp;
        }
        ret = -ENOTCONN;