Commit c6e08d62 authored May 28, 2020 by Chris Lew Committed by David S. Miller May 30, 2020

net: qrtr: Allocate workqueue before kernel_bind

A null pointer dereference in qrtr_ns_data_ready() is seen if a client
opens a qrtr socket before qrtr_ns_init() can bind to the control port.
When the control port is bound, the ENETRESET error will be broadcasted
and clients will close their sockets. This results in DEL_CLIENT
packets being sent to the ns and qrtr_ns_data_ready() being called
without the workqueue being allocated.

Allocate the workqueue before setting sk_data_ready and binding to the
control port. This ensures that the work and workqueue structs are
allocated and initialized before qrtr_ns_data_ready can be called.

Fixes: 0c2204a4 ("net: qrtr: Migrate nameservice to kernel from userspace")
Signed-off-by: Chris Lew <clew@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent e237659c

net/qrtr/ns.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -712,6 +712,10 @@ void qrtr_ns_init(void)
		goto err_sock;
		}

		qrtr_ns.workqueue = alloc_workqueue("qrtr_ns_handler", WQ_UNBOUND, 1);
		if (!qrtr_ns.workqueue)
		goto err_sock;

		qrtr_ns.sock->sk->sk_data_ready = qrtr_ns_data_ready;

		sq.sq_port = QRTR_PORT_CTRL;
		@@ -720,17 +724,13 @@ void qrtr_ns_init(void)
		ret = kernel_bind(qrtr_ns.sock, (struct sockaddr *)&sq, sizeof(sq));
		if (ret < 0) {
		pr_err("failed to bind to socket\n");
		goto err_sock;
		goto err_wq;
		}

		qrtr_ns.bcast_sq.sq_family = AF_QIPCRTR;
		qrtr_ns.bcast_sq.sq_node = QRTR_NODE_BCAST;
		qrtr_ns.bcast_sq.sq_port = QRTR_PORT_CTRL;

		qrtr_ns.workqueue = alloc_workqueue("qrtr_ns_handler", WQ_UNBOUND, 1);
		if (!qrtr_ns.workqueue)
		goto err_sock;

		ret = say_hello(&qrtr_ns.bcast_sq);
		if (ret < 0)
		goto err_wq;

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