Reviewed-by: Nickle Wang <nicklew@nvidia.com>
________________________________
From: devel@edk2.groups.io <devel@edk2.groups.io> on behalf of Chang, Abner via groups.io <abner.chang=amd.com@groups.io>
Sent: Saturday, October 29, 2022 11:59 AM
To: devel@edk2.groups.io <devel@edk2.groups.io>
Cc: Nickle Wang <nickle@csie.io>; Igor Kulchytskyy <igork@ami.com>
Subject: [edk2-devel] [PATCH] RedfishPkg/RedfishDiscoverDxe: Fix memory free issue

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From: Abner Chang <abner.chang@amd.com>

Check the memory block pointer before freeing it.

Cc: Nickle Wang <nickle@csie.io>
Cc: Igor Kulchytskyy <igork@ami.com>
Signed-off-by: Abner Chang <abner.chang@amd.com>
---
 .../RedfishDiscoverDxe/RedfishDiscoverDxe.c      | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/RedfishPkg/RedfishDiscoverDxe/RedfishDiscoverDxe.c b/RedfishPkg/RedfishDiscoverDxe/RedfishDiscoverDxe.c
index 1293ddd633c..1616b5134bc 100644
--- a/RedfishPkg/RedfishDiscoverDxe/RedfishDiscoverDxe.c
+++ b/RedfishPkg/RedfishDiscoverDxe/RedfishDiscoverDxe.c
@@ -261,6 +261,7 @@ Tcp6GetSubnetInfo (

   Tcp6 = (EFI_TCP6_PROTOCOL *)Instance->NetworkInterfaceProtocolInfo.NetworkProtocolInterface;

+  ZeroMem ((VOID *)&IpModedata, sizeof (EFI_IP6_MODE_DATA));
   Status = Tcp6->GetModeData (Tcp6, NULL, NULL, &IpModedata, NULL, NULL);
   if (EFI_ERROR (Status)) {
     DEBUG ((DEBUG_ERROR, "%a: Can't get IP mode data information\n", __FUNCTION__));
@@ -282,12 +283,15 @@ Tcp6GetSubnetInfo (
   }

   Instance->SubnetAddrInfoIPv6Number = IpModedata.AddressCount;
-  CopyMem (
-    (VOID *)Instance->SubnetAddrInfoIPv6,
-    (VOID *)&IpModedata.AddressList,
-    IpModedata.AddressCount * sizeof (EFI_IP6_ADDRESS_INFO)
-    );
-  FreePool (IpModedata.AddressList);
+  if (IpModedata.AddressCount != 0 && IpModedata.AddressList != NULL) {
+    CopyMem (
+      (VOID *)Instance->SubnetAddrInfoIPv6,
+      (VOID *)&IpModedata.AddressList,
+      IpModedata.AddressCount * sizeof (EFI_IP6_ADDRESS_INFO)
+      );
+    FreePool(IpModedata.AddressList);
+  }
+
   return EFI_SUCCESS;
 }

--
2.37.1.windows.1