On Linux kernel 4.16.8 (using Arch Linux) if I eject a USB 3.0 device from my system (unplug or "udisksctl power-off --block-device /dev/sde), it freezes instantly with a null pointer error in XHCI. I've been unable to successfully capture a kernel log of the error (and my cameras did not return usable results) and the screen begins scrolling near-immediately with hung processors in a VT.  I have done a git bisection (between 4.16.7 and 4.16.7) narrowing it down to the following commit:

commit f5331826b0b7a5f2db56a9020ddbb8ce16acdfc0 Author: Mathias Nyman mathias.nyman@linux.intel.com Date:   Thu May 3 17:30:07 2018 +0300

xhci: Fix use-after-free in xhci_free_virt_device

commit 44a182b9d17765514fa2b1cc911e4e65134eef93 upstream.

KASAN found a use-after-free in xhci_free_virt_device+0x33b/0x38e     where xhci_free_virt_device() sets slot id to 0 if udev exists:     if (dev->udev && dev->udev->slot_id)             dev->udev->slot_id = 0;

dev->udev will be true even if udev is freed because dev->udev is     not set to NULL.

set dev->udev pointer to NULL in xhci_free_dev()

The original patch went to stable so this fix needs to be applied     there as well.

Fixes: a400efe455f7 ("xhci: zero usb device slot_id member when disabling and freeing a xhci slot")     Cc: stable@vger.kernel.org     Reported-by: Guenter Roeck linux@roeck-us.net     Reviewed-by: Guenter Roeck linux@roeck-us.net     Tested-by: Guenter Roeck linux@roeck-us.net     Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com     Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org     Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

:040000 040000 356ecdc13bf252535bd51b8558a8173dae546f19 d28f201228652e87e51ba48f5a0ad4539cca5c29 M    drivers

Can I be CC'd on future responses to this? I am not subscribed to the list.

Jacob Saunders