Crash in CLEAR_IF_FIRST handling in tdb

[Jeremy Allison]

On Fri, Oct 05, 2012 at 10:11:47AM +0200, Volker Lendecke wrote:
> 
> Look at the code fragment in tdb_oob():
> 
>         if (st.st_size < (size_t)off + len) {
>                 if (!probe) {
>                         /* Ensure ecode is set for log fn. */
>                         tdb->ecode = TDB_ERR_IO;
>                         TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %u beyond eof at %u\n",
>                                  (int)(off + len), (int)st.st_size));
>                 }
>                 return -1;
>         }
> 
> So if the file has shrunk before tdb_oob, this won't do
> anything but bail. tdb_oob is only to expand files, not
> shrink. That's why that patch is necessary.

Ah, I missed that. I assumed that if tdb_oob() returned
-1 we wouldn't continue, I didn't notice we weren't
checking the return.

Thanks for the clarification.

Jeremy.