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@samsung.com>
---
 drivers/usb/core/hub.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 73f4482d833a..cc0c994e19e5 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -139,6 +139,8 @@ static inline int hub_is_superspeed(struct usb_device *hdev)
 
 static inline int hub_is_superspeedplus(struct usb_device *hdev)
 {
+	if (!hdev->bos)
+		return 0;
 	return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS &&
 		le16_to_cpu(hdev->descriptor.bcdUSB) >= 0x0310 &&
 		hdev->bos->ssp_cap);
-- 
2.17.1

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@samsung.com>
> ---
>  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

Hello. I think I missed the patch.
Thank you for your quick feedback.

Woo-kwang Lee

> 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@samsung.com>
> > ---
> >  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