In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: btmtksdio: Fix kernel oops in btmtksdio_interrupt

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.

https://git.kernel.org/stable/c/4d3d1f2c35a19988d3c5f0ee86038b525e830840

https://git.kernel.org/stable/c/6d7be5afbb41c918d2f12f857f8c7efa50500be2

https://git.kernel.org/stable/c/70a6cf749d9ff9f463490248322e5343199bc267

https://git.kernel.org/stable/c/770a97d3f34b801de1b04737b43e02c55118c41a

https://git.kernel.org/stable/c/874eca93966a786eace87fa6dfb206c2dd9519b1

https://git.kernel.org/stable/c/b062a0b9c1dc1ff63094337dccfe1568d5b62023