Re: [PATCH] iommu/dma: limit iova free size to unmmaped iova

Andrew Morton
2020-05-21T18:49:08Z

On Thu, 21 May 2020 17:00:04 +0530 Prakash Gupta <guptap@codeaurora.org> wrote:

> Limit the iova size while freeing based on unmapped size. In absence of
> this even with unmap failure, invalid iova is pushed to iova rcache and
> subsequently can cause panic while rcache magazine is freed.
>
> Signed-off-by: Prakash Gupta <guptap@codeaurora.org>
>

I think we need a cc:stable here?

> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -472,7 +472,8 @@ static void __iommu_dma_unmap(struct device *dev, dma_addr_t dma_addr,
>
> if (!cookie->fq_domain)
> iommu_tlb_sync(domain, &iotlb_gather);
> - iommu_dma_free_iova(cookie, dma_addr, size);
> + if (unmapped)
> + iommu_dma_free_iova(cookie, dma_addr, unmapped);
> }
>
> static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,

I'll assume that Joerg will handle this fix?