In virtio_balloon_get_config() we initialize a struct virtio_balloon_config
which we then copy to guest memory. However, the local variable is not
zero initialized. This works OK at the moment because we initialize
all the fields in it; however an upcoming kernel header change will
add some new fields. If we don't zero out the whole struct then we
will start leaking a small amount of the contents of QEMU's stack
to the guest as soon as we update linux-headers/ to a set of headers
that includes the new fields.
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
It looks like none of the other virtio devices have this bug.
Tested with "make check" only.
As the commit message notes, must go in before our next headers update.
---
hw/virtio/virtio-balloon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 1728e4f83af..a12677d4d5b 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -311,7 +311,7 @@ out:
static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
- struct virtio_balloon_config config;
+ struct virtio_balloon_config config = {};
config.num_pages = cpu_to_le32(dev->num_pages);
config.actual = cpu_to_le32(dev->actual);
--
2.20.1
