[reactos] 01/01: [NTOBJSHEX] Return early from GetInfoFromPidl when pcidl is null in LPCITEMIDLIST (#4946)

[Muthu R Kumar]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=7fff96e7fe64d3241c83f…

commit 7fff96e7fe64d3241c83f7d866041758105b62cb
Author:     Muthu R Kumar <muthu90tech(a)gmail.com>
AuthorDate: Sat Dec 31 07:53:02 2022 -0800
Commit:     GitHub <noreply(a)github.com>
CommitDate: Sat Dec 31 16:53:02 2022 +0100

    [NTOBJSHEX] Return early from GetInfoFromPidl when pcidl is null in LPCITEMIDLIST
(#4946)
    
    This fixes a crash when attempting to drag-n-drop items from NTObject Namespace and
System Registry.
    CORE-18480, CORE-18481
---
 dll/shellext/ntobjshex/ntobjfolder.cpp | 7 ++++++-
 dll/shellext/ntobjshex/regfolder.cpp   | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/dll/shellext/ntobjshex/ntobjfolder.cpp
b/dll/shellext/ntobjshex/ntobjfolder.cpp
index f4aef063103..32c031619da 100644
--- a/dll/shellext/ntobjshex/ntobjfolder.cpp
+++ b/dll/shellext/ntobjshex/ntobjfolder.cpp
@@ -516,8 +516,13 @@ BOOL CNtObjectFolder::IsFolder(const NtPidlEntry * info)
 
 HRESULT CNtObjectFolder::GetInfoFromPidl(LPCITEMIDLIST pcidl, const NtPidlEntry **
pentry)
 {
-    NtPidlEntry * entry = (NtPidlEntry*) &(pcidl->mkid);
+    if (!pcidl)
+    {
+        DbgPrint("PCIDL is NULL\n");
+        return E_INVALIDARG;
+    }
 
+    NtPidlEntry * entry = (NtPidlEntry*) &(pcidl->mkid);
     if (entry->cb < sizeof(NtPidlEntry))
     {
         DbgPrint("PCIDL too small %l (required %l)\n", entry->cb,
sizeof(NtPidlEntry));
diff --git a/dll/shellext/ntobjshex/regfolder.cpp b/dll/shellext/ntobjshex/regfolder.cpp
index 83683f05171..ace12e5f173 100644
--- a/dll/shellext/ntobjshex/regfolder.cpp
+++ b/dll/shellext/ntobjshex/regfolder.cpp
@@ -469,8 +469,13 @@ BOOL CRegistryFolder::IsFolder(const RegPidlEntry * info)
 
 HRESULT CRegistryFolder::GetInfoFromPidl(LPCITEMIDLIST pcidl, const RegPidlEntry **
pentry)
 {
-    RegPidlEntry * entry = (RegPidlEntry*) &(pcidl->mkid);
+    if (!pcidl)
+    {
+        DbgPrint("PCIDL is NULL\n");
+        return E_INVALIDARG;
+    }
 
+    RegPidlEntry * entry = (RegPidlEntry*) &(pcidl->mkid);
     if (entry->cb < sizeof(RegPidlEntry))
     {
         DbgPrint("PCIDL too small %l (required %l)\n", entry->cb,
sizeof(RegPidlEntry));