[PATCH 5.17 0685/1126] Bluetooth: btmtksdio: Fix kernel oops in btmtksdio_interrupt

Greg Kroah-Hartman
2022-04-05T08:36:53Z

From: Yake Yang <yake.yang@mediatek.com>

[ Upstream commit b062a0b9c1dc1ff63094337dccfe1568d5b62023 ]

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@gmail.com>
Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Yake Yang <yake.yang@mediatek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 86a52eb77e01..9b868f187316 100644
--- a/drivers/bluetooth/btmtksdio.c
+++ b/drivers/bluetooth/btmtksdio.c
@@ -1095,6 +1095,8 @@ 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");
@@ -1102,8 +1104,6 @@ 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 &
--
2.34.1