From: Michael S. Tsirkin <mst@redhat.com>
Date: Thu, 14 Jan 2016 14:00:41 +0000 (+0200)
Subject: virtio_pci: fix use after free on release
X-Git-Tag: v4.1.12-92~150^2~262
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=0cd2bf5c125ad555db6804ed02f7280d9ba41227;p=users%2Fjedix%2Flinux-maple.git

virtio_pci: fix use after free on release

Orabug: 23330783

[ Upstream commit 2989be09a8a9d62a785137586ad941f916e08f83 ]

KASan detected a use-after-free error in virtio-pci remove code. In
virtio_pci_remove(), vp_dev is still used after being freed in
unregister_virtio_device() (in virtio_pci_release_dev() more
precisely).

To fix, keep a reference until cleanup is done.

Fixes: 63bd62a08ca4 ("virtio_pci: defer kfree until release callback")
Reported-by: Jerome Marchand <jmarchan@redhat.com>
Cc: stable@vger.kernel.org
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
(cherry picked from commit 593bd1058b30eb4f0d6949afdfd9c2659d94ae1e)

Signed-off-by: Dan Duval <dan.duval@oracle.com>
---

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index eba1b7ac7294..14f767e8e5c5 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -554,6 +554,7 @@ err_enable_device:
 static void virtio_pci_remove(struct pci_dev *pci_dev)
 {
 	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+	struct device *dev = get_device(&vp_dev->vdev.dev);
 
 	unregister_virtio_device(&vp_dev->vdev);
 
@@ -564,6 +565,7 @@ static void virtio_pci_remove(struct pci_dev *pci_dev)
 
 	pci_release_regions(pci_dev);
 	pci_disable_device(pci_dev);
+	put_device(dev);
 }
 
 static struct pci_driver virtio_pci_driver = {