nvme-tcp: fix signedness bug in nvme_tcp_init_connection()

[ Upstream commit 528361c49962708a60f51a1afafeb00987cebedf ]

The kernel_recvmsg() function returns an int which could be either
negative error codes or the number of bytes received.  The problem is
that the condition:

        if (ret < sizeof(*icresp)) {

is type promoted to type unsigned long and negative values are treated
as high positive values which is success, when they should be treated as
failure.  Handle invalid positive returns separately from negative
error codes to avoid this problem.

Fixes: 578539e09690 ("nvme-tcp: fix connect failure on receiving partial ICResp PDU")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
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 0bcc9bf57d1d05577856f225dc95c64da8a79455..3ee35f94660f98ce82b1ec7073e3505a24daeb4f 100644 (file)
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1521,11 +1521,11 @@ static int nvme_tcp_init_connection(struct nvme_tcp_queue *queue)
        msg.msg_flags = MSG_WAITALL;
        ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
                        iov.iov_len, msg.msg_flags);
-       if (ret < sizeof(*icresp)) {
+       if (ret >= 0 && ret < sizeof(*icresp))
+               ret = -ECONNRESET;
+       if (ret < 0) {
                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;