drm/i915/gvt: Fix mmap range check

zhenyw · zhenyw · commit 51b00d8509dc · 2019-01-15T19:04:45.000+08:00
This is to fix missed mmap range check on vGPU bar2 region and only allow to map vGPU allocated GMADDR range, which means user space should support sparse mmap to get proper offset for mmap vGPU aperture. And this takes care of actual pgoff in mmap request as original code always does from beginning of vGPU aperture. Fixes: 659643f ("drm/i915/gvt/kvmgt: add vfio/mdev support to KVMGT") Cc: "Monroy, Rodrigo Axel" <rodrigo.axel.monroy@intel.com> Cc: "Orrala Contreras, Alfredo" <alfredo.orrala.contreras@intel.com> Cc: stable@vger.kernel.org # v4.10+ Reviewed-by: Hang Yuan <hang.yuan@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -996,7 +996,7 @@ static int intel_vgpu_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
 {
 	unsigned int index;
 	u64 virtaddr;
-	unsigned long req_size, pgoff = 0;
+	unsigned long req_size, pgoff, req_start;
 	pgprot_t pg_prot;
 	struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
 
@@ -1014,7 +1014,17 @@ static int intel_vgpu_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
 	pg_prot = vma->vm_page_prot;
 	virtaddr = vma->vm_start;
 	req_size = vma->vm_end - vma->vm_start;
-	pgoff = vgpu_aperture_pa_base(vgpu) >> PAGE_SHIFT;
+	pgoff = vma->vm_pgoff &
+		((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
+	req_start = pgoff << PAGE_SHIFT;
+
+	if (!intel_vgpu_in_aperture(vgpu, req_start))
+		return -EINVAL;
+	if (req_start + req_size >
+	    vgpu_aperture_offset(vgpu) + vgpu_aperture_sz(vgpu))
+		return -EINVAL;
+
+	pgoff = (gvt_aperture_pa_base(vgpu->gvt) >> PAGE_SHIFT) + pgoff;
 
 	return remap_pfn_range(vma, virtaddr, pgoff, req_size, pg_prot);
 }
