Re: [PATCH 1/1] swiotlb: fix out-of-bounds TLB allocations with CONFIG_SWIOTLB_DYNAMIC

[Christoph Hellwig]

On Wed, Nov 08, 2023 at 01:21:20PM +0100, Petr Tesařík wrote:
> On Wed,  8 Nov 2023 12:12:49 +0100
> Petr Tesarik <petrtesarik@xxxxxxxxxxxxxxx> wrote:
> 
> > From: Petr Tesarik <petr.tesarik1@xxxxxxxxxxxxxxxxxxx>
> > 
> > Limit the free list length to the size of the IO TLB. Transient pool can be
> > smaller than IO_TLB_SEGSIZE, but the free list is initialized with the
> > assumption that the total number of slots is a multiple of IO_TLB_SEGSIZE.
> > As a result, swiotlb_area_find_slots() may allocate slots past the end of
> > a transient IO TLB buffer.
> 
> Just to make it clear, this patch addresses only the memory corruption
> reported by Niklas, without addressing the underlying issues. Where
> corruption happened before, allocations will fail with this patch.

Thanks, I've applied so that we can get it into -rc1.