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 <[email protected]> Cc: Zhichao Gao <[email protected]> Signed-off-by: Maciej Rabeda <[email protected]> Reviewed-by: Siyuan Fu <[email protected]> Acked-by: Zhichao Gao <[email protected]>
venhow · Apr 1, 2020 · 65c73df · 65c73df
1 parent dd7523b
commit 65c73df
Showing 1 changed file with 5 additions and 4 deletions.
diff --git 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 @@ Ping6OnEchoReplyReceived (
     //
     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);
 }
 
 /**