Re: [Bug #11382] e1000e: 2.6.27-rc1 corrupts EEPROM/NVM

[Dave Airlie]

On Thu, Sep 25, 2008 at 9:15 AM, Jiri Kosina <jkosina@xxxxxxx> wrote:
> On Tue, 23 Sep 2008, David Miller wrote:
>
>> I did some snooping around, and while doing so I noticed that the PCI
>> mmap code for x86 doesn't do one bit of range checking on the size, or
>> any other aspect of the request, wrt. the MMIO regions actually mapped
>> in the BARs of the PCI device.
>
> Ugh, indeed. Added Ingo and Jesse to CC.
>
>> Yikes!
>>
>> It just does a reserve_memtype() on the address range, and says "ok".
>>
>> So if, for example, the X server tries to mmap() more than an MMIO bar
>> actually maps, the kernel lets the user do this.
>>
>> It would be very interesting to add the appropriate checks to
>> pci_mmap_page_range() in arch/x86/pci/i386.c, anyone who wants to do
>> this can use the code in arch/sparc64/kernel/pci.c:
>> __pci_mmap_make_offset() as a guide, and see what happens.
>
> Absolutely. Or we can even do some dirty hackery in userspace, like
> LD_PRELOADing X server and checking mmaps() that are close to MMIO regions
> of affected devices.
>
>> If the MMIO space regions of the video cards sit right before the
>> E1000E ones on the effected systems, that would pretty much
>> convince me that this is the kind of problem we are having here.
>
> Unfortunately, looking at the lspci outputs that are in
> https://bugzilla.novell.com/show_bug.cgi?id=425480 it seems to me that the
> MMIO regions are quite far away from each other.
>

Yup on my laptop these were far away and I wondered what could mangle
things that badly.

Well I'm out of the race, my attempts to re-write my eeprom using an
eeprom from an equivalent laptop
have totally failed and my BIOS won't boot anymore - so my laptop is == a brick.

Dave.
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