[PATCH v4 1/5] Bluetooth: btmtksdio: Fix kernel oops in btmtksdio_interrupt

[sean.wang at mediatek.com]

From: Sean Wang <sean.wang at mediatek.com>

Hi Marcel,

Please ignore the series because I put a wrong version as the prefix

I will send the series later.

        Sean

>
>From: Yake Yang <yake.yang at mediatek.com>
>
>Fix the following kernel oops in btmtksdio_interrrupt
>
>[   14.339134]  btmtksdio_interrupt+0x28/0x54
>[   14.339139]  process_sdio_pending_irqs+0x68/0x1a0
>[   14.339144]  sdio_irq_work+0x40/0x70
>[   14.339154]  process_one_work+0x184/0x39c
>[   14.339160]  worker_thread+0x228/0x3e8
>[   14.339168]  kthread+0x148/0x3ac
>[   14.339176]  ret_from_fork+0x10/0x30
>
>That happened because hdev->power_on is already called before sdio_set_drvdata which btmtksdio_interrupt handler relies on is not properly set up.
>
>The details are shown as the below: hci_register_dev would run queue_work(hdev->req_workqueue, &hdev->power_on) as WQ_HIGHPRI workqueue_struct to complete the power-on sequeunce and thus hci_power_on may run before sdio_set_drvdata is done in btmtksdio_probe.
>
>The hci_dev_do_open in hci_power_on would initialize the device and enable the interrupt and thus it is possible that btmtksdio_interrupt is being called right before sdio_set_drvdata is filled out.
>
>When btmtksdio_interrupt is being called and sdio_set_drvdata is not filled , the kernel oops is going to happen because btmtksdio_interrupt access an uninitialized pointer.
>
>Fixes: 9aebfd4a2200 ("Bluetooth: mediatek: add support for MediaTek MT7663S and MT7668S SDIO devices")
>Reviewed-by: Mark Chen <markyawenchen at gmail.com>
>Co-developed-by: Sean Wang <sean.wang at mediatek.com>
>Signed-off-by: Sean Wang <sean.wang at mediatek.com>
>Signed-off-by: Yake Yang <yake.yang at mediatek.com>
>---
> drivers/bluetooth/btmtksdio.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/bluetooth/btmtksdio.c b/drivers/bluetooth/btmtksdio.c index df3f9d090529..9644069cecbb 100644
>--- a/drivers/bluetooth/btmtksdio.c
>+++ b/drivers/bluetooth/btmtksdio.c
>@@ -1281,6 +1281,8 @@ static int btmtksdio_probe(struct sdio_func *func,
>	hdev->manufacturer = 70;
>	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
>
>+	sdio_set_drvdata(func, bdev);
>+
>	err = hci_register_dev(hdev);
>	if (err < 0) {
>		dev_err(&func->dev, "Can't register HCI device\n"); @@ -1288,8 +1290,6 @@ static int btmtksdio_probe(struct sdio_func *func,
>		return err;
>	}
>
>-	sdio_set_drvdata(func, bdev);
>-
>	/* pm_runtime_enable would be done after the firmware is being
>	 * downloaded because the core layer probably already enables
>	 * runtime PM for this func such as the case host->caps &
>--
>2.25.1
>
>