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 <pbonzini@xxxxxxxxxx>
Cc: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Cc: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
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 9b3bd083b411..10bc0879e618 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -497,6 +497,10 @@ 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, nr_cpu_ids, num_vqs);
--
2.25.1
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