Commit e0592acd authored by Xuan Zhuo's avatar Xuan Zhuo Committed by Michael S. Tsirkin
Browse files

virtio_pci: add check for common cfg size 



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: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Message-Id: <20231019034902.7346-1-xuanzhuo@linux.alibaba.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent fafb51a6

drivers/virtio/virtio_pci_modern.c

+36 −0
Original line number Diff line number Diff line
@@ -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(%zu) 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;

drivers/virtio/virtio_pci_modern_dev.c

+1 −1
Original line number Diff line number Diff line
@@ -296,7 +296,7 @@ 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,

include/linux/virtio_pci_modern.h

+1 −0
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ struct virtio_pci_modern_device { 


	size_t notify_len;

	size_t device_len;

	size_t common_len;



	int notify_map_cap;