Re: [edk2-devel] [PATCH v1] ShellPkg: Fix 'ping' command Ip4 receive flow.

["Laszlo Ersek" <lersek@redhat.com>]

Ray, Zhichao,

On 02/27/20 12:02, Maciej Rabeda wrote:
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2032
> 
> 'ping' command's receive flow utilizes a single Rx token which it
> attempts to reuse before recycling the previously received packet.
> This causes a situation where under ICMP traffic,
> Ping6OnEchoReplyReceived() function will receive an already
> recycled packet with EFI_SUCCESS token status and finally
> dereference invalid pointers from RxData structure.
> 
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Zhichao Gao <zhichao.gao@intel.com>
> Signed-off-by: Maciej Rabeda <maciej.rabeda@linux.intel.com>
> ---
>  ShellPkg/Library/UefiShellNetwork1CommandsLib/Ping.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)

can you please review this ShellPkg patch? It's been on the list for
almost a month now.

Thanks
Laszlo

> diff --git a/ShellPkg/Library/UefiShellNetwork1CommandsLib/Ping.c b/ShellPkg/Library/UefiShellNetwork1CommandsLib/Ping.c
> index 23567fa2c1bb..a3fa32515192 100644
> --- a/ShellPkg/Library/UefiShellNetwork1CommandsLib/Ping.c
> +++ b/ShellPkg/Library/UefiShellNetwork1CommandsLib/Ping.c
> @@ -614,6 +614,11 @@ Ping6OnEchoReplyReceived (
>  
>  ON_EXIT:
>  
> +  //
> +  // Recycle the packet before reusing RxToken
> +  //
> +  gBS->SignalEvent (Private->IpChoice == PING_IP_CHOICE_IP6?((EFI_IP6_RECEIVE_DATA*)Private->RxToken.Packet.RxData)->RecycleSignal:((EFI_IP4_RECEIVE_DATA*)Private->RxToken.Packet.RxData)->RecycleSignal);
> +
>    if (Private->RxCount < Private->SendNum) {
>      //
>      // Continue to receive icmp echo reply packets.
> @@ -632,10 +637,6 @@ ON_EXIT:
>      //
>      Private->Status = EFI_SUCCESS;
>    }
> -  //
> -  // Singal to recycle the each rxdata here, not at the end of process.
> -  //
> -  gBS->SignalEvent (Private->IpChoice == PING_IP_CHOICE_IP6?((EFI_IP6_RECEIVE_DATA*)Private->RxToken.Packet.RxData)->RecycleSignal:((EFI_IP4_RECEIVE_DATA*)Private->RxToken.Packet.RxData)->RecycleSignal);
>  }
>  
>  /**
>