Re: [Qemu-devel] [PATCH] usb: ohci avoid multiple eof timers

[Laurent Vivier <lvivier@redhat.com>]

On 16/02/2016 11:04, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
> 
> When transitioning an OHCI controller to the OHCI_USB_OPERATIONAL
> state, it creates an eof timer object in 'ohci_bus_start'.
> It does not check if one already exists. This results in memory
> leakage and null dereference issue. Add a check to avoid it.
> 
> Reported-by: Zuozhi Fzz <zuozhi.fzz@alibaba-inc.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>

Reviewed-by: Laurent Vivier <lvivier@redhat.com>

> ---
>  hw/usb/hcd-ohci.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
> index 7d65818..15f0b44 100644
> --- a/hw/usb/hcd-ohci.c
> +++ b/hw/usb/hcd-ohci.c
> @@ -1331,11 +1331,11 @@ static void ohci_frame_boundary(void *opaque)
>   */
>  static int ohci_bus_start(OHCIState *ohci)
>  {
> -    ohci->eof_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
> -                    ohci_frame_boundary,
> -                    ohci);
> -
> -    if (ohci->eof_timer == NULL) {
> +    if (!ohci->eof_timer) {
> +        ohci->eof_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
> +                                        ohci_frame_boundary, ohci);
> +    }
> +    if (!ohci->eof_timer) {
>          trace_usb_ohci_bus_eof_timer_failed(ohci->name);
>          ohci_die(ohci);
>          return 0;
>