From 6cf5354c1c4b74fd2e5527db084f163e9d4dae4e Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Wed, 25 Sep 2019 16:49:01 -0700 Subject: [PATCH] vfio/type1: untag user pointers in vaddr_get_pfn 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. Link: http://lkml.kernel.org/r/87422b4d72116a975896f2b19b00f38acbd28f33.1563904656.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Eric Auger Reviewed-by: Vincenzo Frascino Reviewed-by: Catalin Marinas Reviewed-by: Kees Cook Cc: Dave Hansen Cc: Will Deacon Cc: Al Viro Cc: Felix Kuehling Cc: Jens Wiklander Cc: Khalid Aziz Cc: Mauro Carvalho Chehab Cc: Mike Rapoport Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 9a50b0558fa9..96fddc1dafc3 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -375,6 +375,8 @@ 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) {