| Message ID | c529e1eeea7700beff197c4456da6a882ce2efb7.1559580831.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: untag user pointers passed to the kernel | expand |
On Mon, Jun 03, 2019 at 06:55:17PM +0200, 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. > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > 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) { > -- > 2.22.0.rc1.311.g5d7573a151-goog >
On Mon, Jun 03, 2019 at 06:55:17PM +0200, 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. > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
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) {
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. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- drivers/vfio/vfio_iommu_type1.c | 2 ++ 1 file changed, 2 insertions(+)