Some buggy devices, the common cfg size may not match the features.
This patch checks the common cfg size for the
features(VIRTIO_F_NOTIF_CONFIG_DATA, VIRTIO_F_RING_RESET). When the
common cfg size does not match the corresponding feature, we fail the
probe and print error message.
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_pci_modern.c | 36 ++++++++++++++++++++++++++
drivers/virtio/virtio_pci_modern_dev.c | 2 +-
include/linux/virtio_pci_modern.h | 1 +
3 files changed, 38 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index d6bb68ba84e5..6a8f5ff05636 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -39,6 +39,39 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features)
__virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
}
+static int __vp_check_common_size_one_feature(struct virtio_device *vdev, u32 fbit,
+ u32 offset, const char *fname)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+ if (!__virtio_test_bit(vdev, fbit))
+ return 0;
+
+ if (likely(vp_dev->mdev.common_len >= offset))
+ return 0;
+
+ dev_err(&vdev->dev,
+ "virtio: common cfg size(%ld) does not match the feature %s\n",
+ vp_dev->mdev.common_len, fname);
+
+ return -EINVAL;
+}
+
+#define vp_check_common_size_one_feature(vdev, fbit, field) \
+ __vp_check_common_size_one_feature(vdev, fbit, \
+ offsetofend(struct virtio_pci_modern_common_cfg, field), #fbit)
+
+static int vp_check_common_size(struct virtio_device *vdev)
+{
+ if (vp_check_common_size_one_feature(vdev, VIRTIO_F_NOTIF_CONFIG_DATA, queue_notify_data))
+ return -EINVAL;
+
+ if (vp_check_common_size_one_feature(vdev, VIRTIO_F_RING_RESET, queue_reset))
+ return -EINVAL;
+
+ return 0;
+}
+
/* virtio config->finalize_features() implementation */
static int vp_finalize_features(struct virtio_device *vdev)
{
@@ -57,6 +90,9 @@ static int vp_finalize_features(struct virtio_device *vdev)
return -EINVAL;
}
+ if (vp_check_common_size(vdev))
+ return -EINVAL;
+
vp_modern_set_features(&vp_dev->mdev, vdev->features);
return 0;
diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c
index 9cb601e16688..33f319da1558 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -292,7 +292,7 @@ int vp_modern_probe(struct virtio_pci_modern_device *mdev)
mdev->common = vp_modern_map_capability(mdev, common,
sizeof(struct virtio_pci_common_cfg), 4,
0, sizeof(struct virtio_pci_modern_common_cfg),
- NULL, NULL);
+ &mdev->common_len, NULL);
if (!mdev->common)
goto err_map_common;
mdev->isr = vp_modern_map_capability(mdev, isr, sizeof(u8), 1,
diff --git a/include/linux/virtio_pci_modern.h b/include/linux/virtio_pci_modern.h
index 067ac1d789bc..edf62bae0474 100644
--- a/include/linux/virtio_pci_modern.h
+++ b/include/linux/virtio_pci_modern.h
@@ -28,6 +28,7 @@ struct virtio_pci_modern_device {
/* So we can sanity-check accesses. */
size_t notify_len;
size_t device_len;
+ size_t common_len;
/* Capability for when we need to map notifications per-vq. */
int notify_map_cap;
--
2.32.0.3.g01195cf9f
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
