From 8b6f5ef6a0cc1613379e60be403e7a957e531b13 Mon Sep 17 00:00:00 2001
From: Yuri Benditovich <yuri.benditovich@daynix.com>
Date: Wed, 10 Apr 2024 00:02:41 +0300
Subject: [PATCH] netkvm: fix memory leak in TX overfragmenting flow

https://issues.redhat.com/browse/RHEL-24992
Memory leak of CNB::m_ExtraNBStorage happens if the
packet os overfragmented but we do not succeed to
allocate extra pages.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
---
 NetKVM/Common/ParaNdis_TX.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/NetKVM/Common/ParaNdis_TX.cpp b/NetKVM/Common/ParaNdis_TX.cpp
index d706ec201..1c7e0a447 100644
--- a/NetKVM/Common/ParaNdis_TX.cpp
+++ b/NetKVM/Common/ParaNdis_TX.cpp
@@ -809,6 +809,11 @@ CNB::~CNB()
     {
         NdisMFreeNetBufferSGList(m_Context->DmaHandle, m_SGL, m_NB);
     }
+    if (m_ExtraNBStorage)
+    {
+        // for unknown case it was not freed before
+        ReturnPages();
+    }
 }
 
 void CNB::ReleaseResources()
@@ -1221,6 +1226,8 @@ NBMappingStatus CNB::AllocateAndFillCopySGL(ULONG ParsedHeadersLength)
     RtlZeroMemory(m_ExtraNBStorage, sizeof(CExtendedNBStorage));
     if (!m_ParentNBL->GetParentTXPath()->BorrowPages(m_ExtraNBStorage, Pages))
     {
+        NdisFreeMemory(m_ExtraNBStorage, sizeof(CExtendedNBStorage), 0);
+        m_ExtraNBStorage = NULL;
         return NBMappingStatus::NO_RESOURCE;
     }