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 <xuanz...@linux.alibaba.com> --- 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@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization