Re: [PATCH 04/16] elfops: add strict bounds checking to get/load_section()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On 5/18/09, Andreas Robinson <andr345@xxxxxxxxx> wrote:
> On Mon, 2009-05-18 at 17:14 +0100, Alan Jenkins wrote:
>> On 5/18/09, Andreas Robinson <andr345@xxxxxxxxx> wrote:
>> > get_section() and load_section() now return NULL if a section header
>> > is corrupt and points to a block that lies partially or entirely
>> > outside the file data buffer.
>>
>> Great!
>>
>> Just out of interest, do you have any ideas about adding bounds
>> checking for strings?  If I remember correctly, there's still a
>> possibility for crashes if next_string() is used on a section which is
>> missing a final NUL terminator.
>
> Hmm, you're right ...
>
> Would it be terribly ugly to have next_string() check that a terminator
> exists at the end of the section and if it doesn't, insert one and then
> write a warning message to the log?

Yeah, terribly ugly :-).  That would require mapping the file as copy
on write (private).  But I _think_ we should be able to run on NOMMU,
where that is not supported.

I would prefer that the program refuse to handle the module if it is
discovered to be corrupt.  I don't think we should try and work around
such corruption.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-modules" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Home]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Photo]     [Yosemite News]    [Yosemite Photos]    [Video Projectors]     [PDAs]     [Free Online Dating]     [Hacking TiVo]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Devices]     [Big List of Linux Books]     [16.7MP]

Add to Google Powered by Linux