On Thu 28 May 16:05 PDT 2020, Chris Lew wrote:
> 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.
>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Regards,
Bjorn
> Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
> Signed-off-by: Chris Lew <clew@xxxxxxxxxxxxxx>
> ---
> net/qrtr/ns.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
> index e7d0fe3f4330..c5b3202a14ca 100644
> --- a/net/qrtr/ns.c
> +++ b/net/qrtr/ns.c
> @@ -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;
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
