virtio-rng: Remove false BUG for spurious callbacks

The virtio-rng drivers checks for spurious callbacks. Since
callbacks can be implemented via shared interrupts (e.g. PCI) this
could lead to guest kernel oopses with lots of virtio devices.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index d0e563e4fc39..86e83f883139 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -37,9 +37,9 @@ static void random_recv_done(struct virtqueue *vq)
 {
         int len;
 
-        /* We never get spurious callbacks. */
+        /* We can get spurious callbacks, e.g. shared IRQs + virtio_pci. */
         if (!vq->vq_ops->get_buf(vq, &len))
-                BUG();
+                return;
 
         data_left = len / sizeof(random_data[0]);
         complete(&have_data);