vdpa: fix use-after-free on vp_vdpa_remove

[PATCH] vdpa: fix use-after-free on vp_vdpa_remove

Posted by Yi Wang 4 years, 3 months ago

From: Zhang Min <zhang.min9@zte.com.cn>

When vp_vdpa driver is unbind, vp_vdpa is freed in vdpa_unregister_device
and then vp_vdpa->mdev.pci_dev is dereferenced in vp_modern_remove,
triggering use-after-free.

Call Trace of unbinding driver free vp_vdpa :
do_syscall_64
  vfs_write
    kernfs_fop_write_iter
      device_release_driver_internal
        pci_device_remove
          vp_vdpa_remove
            vdpa_unregister_device
              kobject_release
                device_release
                  kfree

Call Trace of dereference vp_vdpa->mdev.pci_dev:
vp_modern_remove
  pci_release_selected_regions
    pci_release_region
      pci_resource_len
        pci_resource_end
          (dev)->resource[(bar)].end

Signed-off-by: Zhang Min <zhang.min9@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
---
 drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
index a57e381e830b..cce101e6a940 100644
--- a/drivers/vdpa/virtio_pci/vp_vdpa.c
+++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
@@ -533,8 +533,8 @@ static void vp_vdpa_remove(struct pci_dev *pdev)
 {
 	struct vp_vdpa *vp_vdpa = pci_get_drvdata(pdev);
 
-	vdpa_unregister_device(&vp_vdpa->vdpa);
 	vp_modern_remove(&vp_vdpa->mdev);
+	vdpa_unregister_device(&vp_vdpa->vdpa);
 }
 
 static struct pci_driver vp_vdpa_driver = {
-- 
2.27.0

Re: [PATCH] vdpa: fix use-after-free on vp_vdpa_remove

Posted by Jason Wang 4 years, 3 months ago

On Tue, Mar 1, 2022 at 9:26 AM Yi Wang <wang.yi59@zte.com.cn> wrote:
>
> From: Zhang Min <zhang.min9@zte.com.cn>
>
> When vp_vdpa driver is unbind, vp_vdpa is freed in vdpa_unregister_device
> and then vp_vdpa->mdev.pci_dev is dereferenced in vp_modern_remove,
> triggering use-after-free.
>
> Call Trace of unbinding driver free vp_vdpa :
> do_syscall_64
>   vfs_write
>     kernfs_fop_write_iter
>       device_release_driver_internal
>         pci_device_remove
>           vp_vdpa_remove
>             vdpa_unregister_device
>               kobject_release
>                 device_release
>                   kfree
>
> Call Trace of dereference vp_vdpa->mdev.pci_dev:
> vp_modern_remove
>   pci_release_selected_regions
>     pci_release_region
>       pci_resource_len
>         pci_resource_end
>           (dev)->resource[(bar)].end
>
> Signed-off-by: Zhang Min <zhang.min9@zte.com.cn>
> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>

Acked-by: Jason Wang <jasowang@redhat.com>

> ---
>  drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index a57e381e830b..cce101e6a940 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -533,8 +533,8 @@ static void vp_vdpa_remove(struct pci_dev *pdev)
>  {
>         struct vp_vdpa *vp_vdpa = pci_get_drvdata(pdev);
>
> -       vdpa_unregister_device(&vp_vdpa->vdpa);
>         vp_modern_remove(&vp_vdpa->mdev);
> +       vdpa_unregister_device(&vp_vdpa->vdpa);
>  }
>
>  static struct pci_driver vp_vdpa_driver = {
> --
> 2.27.0
>

Re: [PATCH] vdpa: fix use-after-free on vp_vdpa_remove

Posted by Stefano Garzarella 4 years, 3 months ago

On Tue, Mar 1, 2022 at 2:26 AM Yi Wang <wang.yi59@zte.com.cn> wrote:
>
> From: Zhang Min <zhang.min9@zte.com.cn>
>
> When vp_vdpa driver is unbind, vp_vdpa is freed in vdpa_unregister_device
> and then vp_vdpa->mdev.pci_dev is dereferenced in vp_modern_remove,
> triggering use-after-free.
>
> Call Trace of unbinding driver free vp_vdpa :
> do_syscall_64
>   vfs_write
>     kernfs_fop_write_iter
>       device_release_driver_internal
>         pci_device_remove
>           vp_vdpa_remove
>             vdpa_unregister_device
>               kobject_release
>                 device_release
>                   kfree
>
> Call Trace of dereference vp_vdpa->mdev.pci_dev:
> vp_modern_remove
>   pci_release_selected_regions
>     pci_release_region
>       pci_resource_len
>         pci_resource_end
>           (dev)->resource[(bar)].end

We can add the fixes tag:

Fixes: 64b9f64f80a6 ("vdpa: introduce virtio pci driver")

>
> Signed-off-by: Zhang Min <zhang.min9@zte.com.cn>
> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
> ---
>  drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index a57e381e830b..cce101e6a940 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -533,8 +533,8 @@ static void vp_vdpa_remove(struct pci_dev *pdev)
>  {
>         struct vp_vdpa *vp_vdpa = pci_get_drvdata(pdev);
>
> -       vdpa_unregister_device(&vp_vdpa->vdpa);
>         vp_modern_remove(&vp_vdpa->mdev);
> +       vdpa_unregister_device(&vp_vdpa->vdpa);
>  }
>
>  static struct pci_driver vp_vdpa_driver = {
> --
> 2.27.0
>

The patch LGTM:

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>