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virtio-blk: Add validation for block size in config space

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An untrusted device might presents an invalid block size
in configuration space. This tries to add validation for it
in the validate callback and clear the VIRTIO_BLK_F_BLK_SIZE
feature bit if the value is out of the supported range.

And we also double check the value in virtblk_probe() in
case that it's changed after the validation.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20210809101609.148-1-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Xie Yongji 2021-08-09 18:16:09 +08:00 committed by Michael S. Tsirkin
parent e74cfa91f4
commit 82e89ea077
1 changed files with 33 additions and 6 deletions
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39
drivers/block/virtio_blk.c
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@ -692,6 +692,28 @@ static const struct blk_mq_ops virtio_mq_ops = {
static unsigned int virtblk_queue_depth;
module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
static int virtblk_validate(struct virtio_device *vdev)
{
u32 blk_size;
if (!vdev->config->get) {
dev_err(&vdev->dev, "%s failure: config access disabled\n",
__func__);
return -EINVAL;
}
if (!virtio_has_feature(vdev, VIRTIO_BLK_F_BLK_SIZE))
return 0;
blk_size = virtio_cread32(vdev,
offsetof(struct virtio_blk_config, blk_size));
if (blk_size < SECTOR_SIZE || blk_size > PAGE_SIZE)
__virtio_clear_bit(vdev, VIRTIO_BLK_F_BLK_SIZE);
return 0;
}
static int virtblk_probe(struct virtio_device *vdev)
{
struct virtio_blk *vblk;
@ -703,12 +725,6 @@ static int virtblk_probe(struct virtio_device *vdev)
u8 physical_block_exp, alignment_offset;
unsigned int queue_depth;
if (!vdev->config->get) {
dev_err(&vdev->dev, "%s failure: config access disabled\n",
__func__);
return -EINVAL;
}
err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
GFP_KERNEL);
if (err < 0)
@ -823,6 +839,14 @@ static int virtblk_probe(struct virtio_device *vdev)
else
blk_size = queue_logical_block_size(q);
if (unlikely(blk_size < SECTOR_SIZE || blk_size > PAGE_SIZE)) {
dev_err(&vdev->dev,
"block size is changed unexpectedly, now is %u\n",
blk_size);
err = -EINVAL;
goto err_cleanup_disk;
}
/* Use topology information if available */
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
struct virtio_blk_config, physical_block_exp,
@ -881,6 +905,8 @@ static int virtblk_probe(struct virtio_device *vdev)
device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups);
return 0;
err_cleanup_disk:
blk_cleanup_disk(vblk->disk);
out_free_tags:
blk_mq_free_tag_set(&vblk->tag_set);
out_free_vq:
@ -983,6 +1009,7 @@ static struct virtio_driver virtio_blk = {
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.validate = virtblk_validate,
.probe = virtblk_probe,
.remove = virtblk_remove,
.config_changed = virtblk_config_changed,