Office 2007 MSI Crash - Null dereference @ MsiViewExecute

[James Hawkins]

On Sun, May 3, 2009 at 1:52 PM, Mike Kaplinskiy
<mike.kaplinskiy at gmail.com> wrote:
> On Thu, Apr 30, 2009 at 1:08 PM, James Hawkins <truiken at gmail.com> wrote:
>> On Thu, Apr 30, 2009 at 4:03 AM, Austin English <austinenglish at gmail.com> wrote:
>>> On Tue, Apr 28, 2009 at 9:27 PM, Mike Kaplinskiy
>>> <mike.kaplinskiy at gmail.com> wrote:
>>>> I was looking at the trace of the crash from bug 17600, and it looks like
>>>> a custom action is calling MsiViewExecute with a null hRec.
>>>>
>>>> I (sadly) don't know much about the wine MSI architecture, but the
>>>> msiobj_lock on line 484 should fail since rec will never be fetched
>>>> (null). I think the intention was to make it query->hdr (as it is
>>>> released later).
>>>
>>> A testcase for it would show if you're right or wrong ;-).
>>>
>>
>> Not really.  If you grep through the msi tests, you'll see that we
>> call MsiViewExecute with NULL hRec all over the place.  That doesn't
>> mean there isn't a bug, just saying.
>>
>> --
>> James Hawkins
>>
>
> So I got a little time to look into this, and was completely blown
> away. Apparently doing
>
> TRACE("dereferencing 0?=%p\n", (void *) &(((MSIRECORD *) NULL)->hdr));
>
> works, since nothing ever gets dereferenced. I will post a patch for
> this small nit.
>
> On a slightly different note, I have traced the problem in office 2007
> to the patch by James, and in particular to INSERT_execute. The row
> index gets set to 0 if the primary key is null (which is what office
> install is doing), but if the insert is temporary TABLE_insert assumes
> that row >= tv->table->row_count, and subtracts from the row index,
> putting us in the negatives (or high positives due to uint).
>
> I have a patch for this, but I don't know how to make a testcase (all
> I know is office installs), so would anyone mind pointing me to
> somewhere that explains msi temporary inserts?
>
> And should I post the patch up on wine-patches to get it critiqued?
> (sorry, first time)
>

I'll take a look at your patch.  No offense intended, but it's
probably not correct.  The problem is a beast and deeply rooted in the
way we store temporary rows in the DB.  I have a huge test patch for
it, and I had a fix, but my linux HD got fragged (bummer).

-- 
James Hawkins