Re: [PATCH]: iommu fix potential overflow in alloc_iommu()

[Prarit Bhargava]

FUJITA Tomonori wrote:
> On Mon, 21 Jul 2008 10:15:22 -0400
> Prarit Bhargava <prarit@xxxxxxxxxx> wrote:
>
>   
> > (This didn't appear on LKML or any of the mirrors ... trying again)
> >
> > It is possible that alloc_iommu()'s boundary_size overflows as
> > dma_get_seg_boundary can return 0xffffffff.  In that case, further usage of
> > boundary_size triggers a BUG_ON() in the iommu code.
> >     
>
> Did you actually hit this? pci-gart_64.c is used only by X86_64.
>   

I hit this by declaring a device struct and not declaring a value for 
dev->dma_parms->segment_boundary_mask.

I was attempting to alloc out of the IOMMU and the code then dies on the 
bugcheck in iommu_is_span_boundary() because boundary_size = 0.

P.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/