| Message ID | e86d8cd6bd0ade9cce6304594bcaf0c8e7f788b0.1560339705.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: untag user pointers passed to the kernel | expand |
On 12/06/2019 12:43, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 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: Catalin Marinas <catalin.marinas@arm.com> > Reviewed-by: Kees Cook <keescook@chromium.org> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.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 3ddc375e7063..528e39a1c2dd 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -384,6 +384,8 @@ 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) { >
Hi Andrey, On 6/12/19 1:43 PM, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 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: Catalin Marinas <catalin.marinas@arm.com> > Reviewed-by: Kees Cook <keescook@chromium.org> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Thanks Eric > --- > 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 3ddc375e7063..528e39a1c2dd 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -384,6 +384,8 @@ 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) { >
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 3ddc375e7063..528e39a1c2dd 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -384,6 +384,8 @@ 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) {