Re: [PATCH] usb: core: add bos NULL pointer checking condition

[Greg KH]

On Wed, Oct 04, 2023 at 03:26:42PM +0900, Woo-kwang Lee wrote:
> This issue occurs when connecting Galaxy S22 and abnormal SEC Dex Adapter.
> When the abnormal adapter is connected, kernel panic always occurs after a
> few seconds.
> This occurs due to unable to get BOS descriptor, usb_release_bos_descriptor
> set dev->bos = NULL.
> 
> - usb_reset_and_verify_device
>   - hub_port_init
>   - usb_release_bos_descriptor
>     - dev->bos = NULL;
> 
> hub_port_connect_change() calls portspeed(), and portspeed() calls hub_is_s
> uperspeedplus().
> Finally, hub_is_superspeedplus() calls hdev->bos->ssp_cap.
> It needs to check hdev->bos is NULL to prevent a kernel panic.
> 
> usb 3-1: new SuperSpeed Gen 1 USB device number 16 using xhci-hcd-exynos
> usb 3-1: unable to get BOS descriptor set
> usb 3-1: Product: USB3.0 Hub
> Unable to handle kernel NULL pointer dereference at virtual address 0000018
> 
> Call trace:
>  hub_port_connect_change+0x8c/0x538
>  port_event+0x244/0x764
>  hub_event+0x158/0x474
>  process_one_work+0x204/0x550
>  worker_thread+0x28c/0x580
>  kthread+0x13c/0x178
>  ret_from_fork+0x10/0x30
> 
> - hub_port_connect_change
>   - portspeed
>     - hub_is_superspeedplus
> 
> Fixes: 0cdd49a1d1a4 ("usb: Support USB 3.1 extended port status request")
> Signed-off-by: Woo-kwang Lee <wookwang.lee@xxxxxxxxxxx>
> ---
>  drivers/usb/core/hub.h | 2 ++
>  1 file changed, 2 insertions(+)

Are you sure this isn't already fixed by commit f74a7afc224a ("usb: hub:
Guard against accesses to uninitialized BOS descriptors") in linux-next?

thanks,

greg k-h