Re: [PATCH 1/1] NetworkPkg/ArpDxe: Recycle invalid ARP packets(CVE-2019-14559).

["Siyuan, Fu" <siyuan.fu@intel.com>]

Hi, Nicholas

Should the signal recycle event also be added to below if condition?

  if (RxData->DataLength < sizeof (ARP_HEAD)) {
    //
    // Restart the receiving if packet size is not correct.
    //
    goto RESTART_RECEIVE;
  }


Best Regards
Siyuan 

> -----Original Message-----
> From: Armour, Nicholas <nicholas.armour@intel.com>
> Sent: 2020年2月13日 7:54
> To: devel@edk2.groups.io
> Cc: Armour, Nicholas <nicholas.armour@intel.com>; Wu, Jiaxin
> <jiaxin.wu@intel.com>; Maciej Rabeda <maciej.rabeda@linux.intel.com>; Fu,
> Siyuan <siyuan.fu@intel.com>
> Subject: [PATCH 1/1] NetworkPkg/ArpDxe: Recycle invalid ARP packets(CVE-
> 2019-14559).
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2031
> 
> This patch triggers the RecycleEvent for invalid ARP packets.
> Prior to this, we would just ignore invalid ARP packets,
> and never free them.
> 
> Cc: Jiaxin Wu <jiaxin.wu@intel.com>
> Cc: Maciej Rabeda <maciej.rabeda@linux.intel.com>
> Cc: Siyuan Fu <siyuan.fu@intel.com>
> Signed-off-by: Nicholas Armour <nicholas.armour@intel.com>
> ---
>  NetworkPkg/ArpDxe/ArpImpl.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/NetworkPkg/ArpDxe/ArpImpl.c b/NetworkPkg/ArpDxe/ArpImpl.c
> index 9cdb33f2bd66..09fc8811f125 100644
> --- a/NetworkPkg/ArpDxe/ArpImpl.c
> +++ b/NetworkPkg/ArpDxe/ArpImpl.c
> @@ -125,6 +125,7 @@ ArpOnFrameRcvdDpc (
>    Head->OpCode    = NTOHS (Head->OpCode);
> 
>    if (RxData->DataLength < (sizeof (ARP_HEAD) + 2 * Head->HwAddrLen + 2 *
> Head->ProtoAddrLen)) {
> +    gBS->SignalEvent (RxData->RecycleEvent);
>      goto RESTART_RECEIVE;
>    }
> 
> --
> 2.16.2.windows.1