Messages in this thread Patch in this message | | | From | Joe Jin <> | Subject | [PATCH] x86/xen: add physically contiguous check to xen_destroy_contiguous_region | Date | Thu, 25 Oct 2018 17:16:12 -0700 |
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xen_destroy_contiguous_region() used to exchange physically contiguous memory with hypervisor, but it does not verify that the memory is physically contiguous or no, passing non-contiguous memory to xen_destroy_contiguous_region() will lead kernel panic.
Signed-off-by: Joe Jin <joe.jin@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> --- arch/x86/xen/mmu_pv.c | 3 +++ drivers/xen/swiotlb-xen.c | 3 +-- 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index 70ea598a37d2..c2f081f8ebe3 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -2649,6 +2649,9 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) if (unlikely(order > MAX_CONTIG_ORDER)) return; + if (range_straddles_page_boundary(pstart, PAGE_SIZE << order)) + return; + vstart = (unsigned long)phys_to_virt(pstart); memset((void *) vstart, 0, PAGE_SIZE << order); diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index f5c1af4ce9ab..432eeae02d7d 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -357,8 +357,7 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, /* Convert the size to actually allocated. */ size = 1UL << (order + XEN_PAGE_SHIFT); - if (((dev_addr + size - 1 <= dma_mask)) || - range_straddles_page_boundary(phys, size)) + if (dev_addr + size - 1 <= dma_mask) xen_destroy_contiguous_region(phys, order); xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs); -- 2.17.1 (Apple Git-112)
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