[PATCH 4.19 06/29] vfio/pci: Move dummy_resources_list init in vfio_pci_probe()

Greg Kroah-Hartman
2021-01-05T09:31:14Z

From: Eric Auger <eric.auger@redhat.com>

[ Upstream commit 16b8fe4caf499ae8e12d2ab1b1324497e36a7b83 ]

In case an error occurs in vfio_pci_enable() before the call to
vfio_pci_probe_mmaps(), vfio_pci_disable() will try to iterate
on an uninitialized list and cause a kernel panic.

Lets move to the initialization to vfio_pci_probe() to fix the
issue.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Fixes: 05f0c03fbac1 ("vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive")
CC: Stable <stable@vger.kernel.org> # v4.7+
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/vfio/pci/vfio_pci.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 5e23e4aa5b0a3..c48e1d84efb6b 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -118,8 +118,6 @@ static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev)
int bar;
struct vfio_pci_dummy_resource *dummy_res;

- INIT_LIST_HEAD(&vdev->dummy_resources_list);
-
for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
res = vdev->pdev->resource + bar;

@@ -1522,6 +1520,7 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
mutex_init(&vdev->igate);
spin_lock_init(&vdev->irqlock);
mutex_init(&vdev->ioeventfds_lock);
+ INIT_LIST_HEAD(&vdev->dummy_resources_list);
INIT_LIST_HEAD(&vdev->ioeventfds_list);
mutex_init(&vdev->vma_lock);
INIT_LIST_HEAD(&vdev->vma_list);
--
2.27.0