From: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Date: Thu, 27 Feb 2020 10:30:43 +0000 (+0100)
Subject: ShellPkg: Fix 'ping' command Ip4 receive flow.
X-Git-Tag: edk2-stable202005~238
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=65c73df44c61235ede84c5aa1d2eab6650844966

ShellPkg: Fix 'ping' command Ip4 receive flow.

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>
Reviewed-by: Siyuan Fu <siyuan.fu@intel.com>
Acked-by: Zhichao Gao <zhichao.gao@intel.com>
---

diff --git a/ShellPkg/Library/UefiShellNetwork1CommandsLib/Ping.c b/ShellPkg/Library/UefiShellNetwork1CommandsLib/Ping.c
index 23567fa2c1..a3fa325151 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);
 }
 
 /**