[Qemu-devel] [PATCH] virtio-net: Fix lduw_p() pointer argument of wrong size

[Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>]

A pointer to a size_t variable was passed as the void * pointer to
lduw_p() in virtio_net_receive().  Instead of acting on the 16-bit value
this caused failure on big-endian hosts.

Avoid this issue in the future by using stw_p() instead.  In general we
should use ld*_p() for loading from target memory and st*_p() for
storing to target memory anyway, not the other way around.

Also tighten up a correct use of lduw_p() when stw_p() should be used
instead in virtio_net_get_config().

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 hw/virtio-net.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 20cf680..5962298 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -79,7 +79,7 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     VirtIONet *n = to_virtio_net(vdev);
     struct virtio_net_config netcfg;
 
-    netcfg.status = lduw_p(&n->status);
+    stw_p(&netcfg.status, n->status);
     memcpy(netcfg.mac, n->mac, ETH_ALEN);
     memcpy(config, &netcfg, sizeof(netcfg));
 }
@@ -679,7 +679,7 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
     }
 
     if (mhdr) {
-        mhdr->num_buffers = lduw_p(&i);
+        stw_p(&mhdr->num_buffers, i);
     }
 
     virtqueue_flush(n->rx_vq, i);
-- 
1.7.2.3