On Thu, Sep 13, 2018 at 02:10:24PM -0700, Matthias Kaehlcke wrote:
> From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxxx>
> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> ---
> The original fix has been integrated into some recent -stable versions,
> but wasn't backported to older LTS kernel like v4.9 or v4.4. The context
> in xhci_free_dev() changed a bit because upstream added
> xhci_disable_slot().
Now queued up, thanks.
greg k-h
