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.mari...@arm.com>
Reviewed-by: Kees Cook <keesc...@chromium.org>
Signed-off-by: Andrey Konovalov <andreyk...@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 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.rc2.383.gf4fbbf30c2-goog

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Reply via email to