Patch-mainline: 5.17

Git-commit: eb057b44dbe35ae14527830236a92f51de8f9184

References: git-fixes

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

Date: Tue, 1 Mar 2022 17:10:59 +0800

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

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>

Link: https://lore.kernel.org/r/20220301091059.46869-1-wang.yi59@zte.com.cn

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

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

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

Signed-off-by: Juergen Gross <jgross@suse.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 = {

-- 

2.35.3