[PATCH V2 01/12] virtio-blk: validate num_queues during probe
From: Jason Wang <jasowang@redhat.com>
Date: 2021-10-12 06:53:08
Also in:
lkml
Subsystem:
block layer, the rest, virtio block and scsi drivers, virtio core · Maintainers:
Jens Axboe, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
If an untrusted device neogitates BLK_F_MQ but advertises a zero num_queues, the driver may end up trying to allocating zero size buffers where ZERO_SIZE_PTR is returned which may pass the checking against the NULL. This will lead unexpected results. Fixing this by using single queue if num_queues is zero. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/block/virtio_blk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 9b3bd083b411..9deff01a38cb 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c@@ -495,7 +495,8 @@ static int init_vq(struct virtio_blk *vblk) err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, struct virtio_blk_config, num_queues, &num_vqs); - if (err) + /* We need at least one virtqueue */ + if (err || !num_vqs) num_vqs = 1; num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs);
--
2.25.1
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