Re: [PATCH 1/9] virtio-blk: validate num_queues during probe
From: Stefano Garzarella <sgarzare@redhat.com>
Date: 2021-09-13 07:48:25
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On Mon, Sep 13, 2021 at 01:53:45PM +0800, Jason Wang wrote:
quoted hunk ↗ jump to hunk
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> Signed-off-by: Jason Wang <redacted> --- 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 e574fbf5e6df..f130d12df4b9 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c@@ -498,7 +498,8 @@ 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 on virtqueue */
s/on/one/ The rest LGTM. Stefano
+ if (err || !num_vqs) num_vqs = 1; num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); -- 2.25.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
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