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

["Gao, Zhichao" <zhichao.gao@intel.com>]

The ping command implementation would go into the ip4/ip6 protocol. But I am not familiar with the network part.

Jiaxin/Siyuan,

Can you help to review this patch?

Thanks,
Zhichao

> -----Original Message-----
> From: Laszlo Ersek [mailto:lersek@redhat.com]
> Sent: Wednesday, March 25, 2020 7:34 PM
> To: Ni, Ray <ray.ni@intel.com>; Gao, Zhichao <zhichao.gao@intel.com>
> Cc: devel@edk2.groups.io; maciej.rabeda@linux.intel.com
> Subject: Re: [edk2-devel] [PATCH v1] ShellPkg: Fix 'ping' command Ip4
> receive flow.
> 
> 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.R
> > + xData)->RecycleSignal:((EFI_IP4_RECEIVE_DATA*)Private-
> >RxToken.Packe
> > + t.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.RxD
> > ata)->RecycleSignal:((EFI_IP4_RECEIVE_DATA*)Private-
> >RxToken.Packet.Rx
> > Data)->RecycleSignal);
> >  }
> >
> >  /**
> >