From 6ae6ff6f6e7d2f304a12a53af8298e4f16ad633e Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Tue, 19 Oct 2021 15:01:43 +0800 Subject: [PATCH] virtio-blk: validate num_queues during probe 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 failing the probe in this case. Cc: Paolo Bonzini Cc: Stefan Hajnoczi Cc: Stefano Garzarella Signed-off-by: Jason Wang Link: https://lore.kernel.org/r/20211019070152.8236-2-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefano Garzarella Reviewed-by: Stefan Hajnoczi --- drivers/block/virtio_blk.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index a33fe07436722..dbcf2a7e4a00c 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -571,6 +571,10 @@ static int init_vq(struct virtio_blk *vblk) &num_vqs); if (err) num_vqs = 1; + if (!err && !num_vqs) { + dev_err(&vdev->dev, "MQ advertisted but zero queues reported\n"); + return -EINVAL; + } num_vqs = min_t(unsigned int, min_not_zero(num_request_queues, nr_cpu_ids), -- 2.30.2