Messages in this thread Patch in this message | | | Date | Mon, 24 Jun 2019 16:32:59 +0200 | Subject | [PATCH v18 14/15] vfio/type1: untag user pointers in vaddr_get_pfn | From | Andrey Konovalov <> |
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This patch is a part of a series that extends kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments.
vaddr_get_pfn() uses provided user pointers for vma lookups, which can only by done with untagged pointers.
Untag user pointers in this function.
Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- drivers/vfio/vfio_iommu_type1.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index add34adfadc7..7b8283e33d10 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -381,6 +381,8 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, down_read(&mm->mmap_sem); + vaddr = untagged_addr(vaddr); + vma = find_vma_intersection(mm, vaddr, vaddr + 1); if (vma && vma->vm_flags & VM_PFNMAP) { -- 2.22.0.410.gd8fdbe21b5-goog
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