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

[Woo-kwang Lee]

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@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