2020-11-13 17:54:05

by Eric Auger

Subject: [PATCH] vfio/pci: Move dummy_resources_list init in vfio_pci_probe()

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 <[email protected]>
Fixes: 05f0c03fbac1 ("vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive")
CC: Stable <[email protected]> # v4.7+
---
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 e6190173482c..47ebc5c49ca4 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -161,8 +161,6 @@ static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev)
int i;
struct vfio_pci_dummy_resource *dummy_res;

- INIT_LIST_HEAD(&vdev->dummy_resources_list);
-
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
int bar = i + PCI_STD_RESOURCES;

@@ -1966,6 +1964,7 @@ 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);
--
2.21.3

2020-12-03 23:55:17

by Alex Williamson

Subject: Re: [PATCH] vfio/pci: Move dummy_resources_list init in vfio_pci_probe()

On Fri, 13 Nov 2020 18:52:02 +0100
Eric Auger <[email protected]> wrote:

> 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 <[email protected]>
> Fixes: 05f0c03fbac1 ("vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive")
> CC: Stable <[email protected]> # v4.7+
> ---
> drivers/vfio/pci/vfio_pci.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)

Thanks, Eric. Applied to vfio next branch for v5.11.

Alex

>
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index e6190173482c..47ebc5c49ca4 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -161,8 +161,6 @@ static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev)
> int i;
> struct vfio_pci_dummy_resource *dummy_res;
>
> - INIT_LIST_HEAD(&vdev->dummy_resources_list);
> -
> for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> int bar = i + PCI_STD_RESOURCES;
>
> @@ -1966,6 +1964,7 @@ 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);