1 files changed, 22 insertions, 6 deletions

diff --git a/net/net.c b/net/net.c
index 4d1ff7ae47..0520bc1681 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1514,18 +1514,34 @@ static void net_vm_change_state_handler(void *opaque, bool running,
 
 void net_cleanup(void)
 {
-    NetClientState *nc;
+    NetClientState *nc, **p = &QTAILQ_FIRST(&net_clients);
 
     /*cleanup colo compare module for COLO*/
     colo_compare_cleanup();
 
-    /* We may del multiple entries during qemu_del_net_client(),
-     * so QTAILQ_FOREACH_SAFE() is also not safe here.
+    /*
+     * Walk the net_clients list and remove the netdevs but *not* any
+     * NET_CLIENT_DRIVER_NIC entries. The latter are owned by the device
+     * model which created them, and in some cases (e.g. xen-net-device)
+     * the device itself may do cleanup at exit and will be upset if we
+     * just delete its NIC from underneath it.
+     *
+     * Since qemu_del_net_client() may delete multiple entries, using
+     * QTAILQ_FOREACH_SAFE() is not safe here. The only safe pointer
+     * to keep as a bookmark is a NET_CLIENT_DRIVER_NIC entry, so keep
+     * 'p' pointing to either the head of the list, or the 'next' field
+     * of the latest NET_CLIENT_DRIVER_NIC, and operate on *p as we walk
+     * the list.
+     *
+     * The 'nc' variable isn't part of the list traversal; it's purely
+     * for convenience as too much '(*p)->' has a tendency to make the
+     * readers' eyes bleed.
      */
-    while (!QTAILQ_EMPTY(&net_clients)) {
-        nc = QTAILQ_FIRST(&net_clients);
+    while (*p) {
+        nc = *p;
         if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
-            qemu_del_nic(qemu_get_nic(nc));
+            /* Skip NET_CLIENT_DRIVER_NIC entries */
+            p = &QTAILQ_NEXT(nc, next);
         } else {
             qemu_del_net_client(nc);
         }