[Bug 48245] New: wbemlocator parse_resource contains non-null terminated string, causing garbage output in trace logs

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48245

Bug ID: 48245
           Summary: wbemlocator parse_resource contains non-null
                    terminated string, causing garbage output in trace
                    logs
           Product: Wine
           Version: 4.21
          Hardware: x86-64
                OS: Linux
            Status: NEW
          Severity: trivial
          Priority: P2
         Component: wmi&wbemprox
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Hello folks,

found while investigating/relay tracing an app that makes use of WMI:

--- snip ---
...
004a:trace:wbemprox:wbem_locator_ConnectServer 0077F6A0, L"\\.\ROOT\CIMV2",
(null), (null), (null), 0x00000000, (null), 00000000, 0146FE14)
004a:Call ntdll.RtlAllocateHeap(00110000,00000000,00000004) ret=6795ad1b
004a:trace:heap:RtlAllocateHeap (0x110000,70000062,00000004): returning
0x77cd30
004a:Ret  ntdll.RtlAllocateHeap() retval=0077cd30 ret=6795ad1b
004a:Call msvcrt.memcpy(0077cd30,001f4ec8,00000002) ret=6795ad3b
004a:Ret  msvcrt.memcpy() retval=0077cd30 ret=6795ad3b
004a:Call msvcrt._wcsnicmp(6796ab4c
L"ROOT\3130\3332\3534\3736\3938\6261\6463\6665\6277\6d65\6c5f\636f\7461\726f\435f\6e6f\656e\7463\6553\7672\7265",001f4ecc
L"ROOT\CIMV2",00000004) ret=6795b074
004a:Ret  msvcrt._wcsnicmp() retval=00000000 ret=6795b074
004a:Call msvcrt._wcsicmp(001f4ed6 L"CIMV2",6796ab40 L"CIMV2") ret=6795aec0
004a:Ret  msvcrt._wcsicmp() retval=00000000 ret=6795aec0
004a:Call ntdll.RtlAllocateHeap(00110000,00000000,0000000c) ret=6795af05
004a:trace:heap:RtlAllocateHeap (0x110000,70000062,0000000c): returning
0x1d3af0
004a:Ret  ntdll.RtlAllocateHeap() retval=001d3af0 ret=6795af05
004a:Call msvcrt.memcpy(001d3af0,001f4ecc,0000000a) ret=6795af25
004a:Ret  msvcrt.memcpy() retval=001d3af0 ret=6795af25
004a:Call msvcrt.wcscmp(0077cd30 L".",6796ab2c L".") ret=6795abe6
004a:Ret  msvcrt.wcscmp() retval=00000000 ret=6795abe6
004a:trace:wbemprox:WbemServices_create (0146FE14) 
...
--- snip ---

The trace log contains garbage characters because the string is not NULL
terminated. Technically there is nothing wrong here - but still it would make
the log output less suspicious (uninitialized/corrupted memory).

Wine source:

https://source.winehq.org/git/wine.git/blob/dba0dd41613a91f17142a9bd8ea12b5a...

--- snip ---
  99 static HRESULT parse_resource( const WCHAR *resource, WCHAR **server,
WCHAR **namespace )
 100 {
 101     static const WCHAR rootW[] = {'R','O','O','T'};
 102     static const WCHAR cimv2W[] = {'C','I','M','V','2',0};
 103     static const WCHAR defaultW[] = {'D','E','F','A','U','L','T',0};
 104     HRESULT hr = WBEM_E_INVALID_NAMESPACE;
 105     const WCHAR *p, *q;
 106     unsigned int len;
 107 
 108     *server = NULL;
 109     *namespace = NULL;
 110     p = q = resource;
 111     if (*p == '\' || *p == '/')
 112     {
 113         p++;
 114         if (*p == '\' || *p == '/') p++;
 115         if (!*p) return WBEM_E_INVALID_NAMESPACE;
 116         if (*p == '\' || *p == '/') return WBEM_E_INVALID_PARAMETER;
 117         q = p + 1;
 118         while (*q && *q != '\' && *q != '/') q++;
 119         if (!*q) return WBEM_E_INVALID_NAMESPACE;
 120         len = q - p;
 121         if (!(*server = heap_alloc( (len + 1) * sizeof(WCHAR) )))
 122         {
 123             hr = E_OUTOFMEMORY;
 124             goto done;
 125         }
 126         memcpy( *server, p, len * sizeof(WCHAR) );
 127         (*server)[len] = 0;
 128         q++;
 129     }
 130     if (!*q) goto done;
 131     p = q;
 132     while (*q && *q != '\' && *q != '/') q++;
 133     len = q - p;
 134     if (len >= ARRAY_SIZE( rootW ) && wcsnicmp( rootW, p, len )) goto
done;
 135     if (!*q)
...
 158     return hr;
 159 }
--- snip ---

Line 101 'rootW' causing garbage trace output in line 134.

$ wine --version
wine-4.21-183-gac24504034

Regards