[PATCH 02/11] virtio: pci: Bounds check device config access

Andrew Scull
2022-03-20T11:43:46Z

The device config is optional, so check it was present and mapped before
trying to use the pointer. Bounds violations are an error, not just a
warning, so bail if the checks fail.

Signed-off-by: Andrew Scull <ascull@google.com>
---
drivers/virtio/virtio_pci_modern.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 55d25cb81b..bcf9f18997 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -114,7 +114,11 @@ static int virtio_pci_get_config(struct udevice *udev, unsigned int offset,
__le16 w;
__le32 l;

- WARN_ON(offset + len > priv->device_len);
+ if (!priv->device)
+ return -ENOSYS;
+
+ if (offset + len > priv->device_len)
+ return -EINVAL;

switch (len) {
case 1:
@@ -136,7 +140,7 @@ static int virtio_pci_get_config(struct udevice *udev, unsigned int offset,
memcpy(buf + sizeof(l), &l, sizeof(l));
break;
default:
- WARN_ON(true);
+ return -EINVAL;
}

return 0;
@@ -150,7 +154,11 @@ static int virtio_pci_set_config(struct udevice *udev, unsigned int offset,
__le16 w;
__le32 l;

- WARN_ON(offset + len > priv->device_len);
+ if (!priv->device)
+ return -ENOSYS;
+
+ if (offset + len > priv->device_len)
+ return -EINVAL;

switch (len) {
case 1:
@@ -172,7 +180,7 @@ static int virtio_pci_set_config(struct udevice *udev, unsigned int offset,
iowrite32(le32_to_cpu(l), priv->device + offset + sizeof(l));
break;
default:
- WARN_ON(true);
+ return -EINVAL;
}

return 0;
--
2.35.1.894.gb6a874cedc-goog