Messages in this thread | | | Date | Thu, 16 Sep 2004 16:26:38 +0200 | From | Andrea Arcangeli <> | Subject | Re: truncate shows non zero data beyond the end of the inode with MAP_SHARED |
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On Thu, Sep 16, 2004 at 10:49:33AM +0200, Helge Hafting wrote: > Could this "garbage" possibly be confidential data?
I don't buy much in this theory.
> I.e. one user repeatedly makes and mmaps a 1-byte file, > extends it to 4k, and looks at the 4095 bytes of "garbage". > Maybe he finds some "interesting stuff" when someone else's > confidential file just got dropped from pagecache > so he could mmap this 1-byte file?
the old data got flushed below the i_size anyways, it sounds very strange that confidential data is present only over the i_size and not below the i_size, and if this guy has confidential data below the i_size then it'd better memset the whole page. And in theory nobody should touch the data over the i_size even if mmap allows to map it. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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