tap: fix memory leak on failure in net_init_tap()

Commit 091a6b2ac fixed most of the memory leaks in failure
paths in net_init_tap() reported by Coverity (CID 1356216),
but missed one. Fix it by deferring the allocation of
fds and vhost_fds until after the error check.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/net/tap.c b/net/tap.c
index b6896a7..6248e85 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -788,8 +788,8 @@ int net_init_tap(const Netdev *netdev, const char *name,
             return -1;
         }
     } else if (tap->has_fds) {
-        char **fds = g_new0(char *, MAX_TAP_QUEUES);
-        char **vhost_fds = g_new0(char *, MAX_TAP_QUEUES);
+        char **fds;
+        char **vhost_fds;
         int nfds, nvhosts;
 
         if (tap->has_ifname || tap->has_script || tap->has_downscript ||
@@ -801,6 +801,9 @@ int net_init_tap(const Netdev *netdev, const char *name,
             return -1;
         }
 
+        fds = g_new0(char *, MAX_TAP_QUEUES);
+        vhost_fds = g_new0(char *, MAX_TAP_QUEUES);
+
         nfds = get_fds(tap->fds, fds, MAX_TAP_QUEUES);
         if (tap->has_vhostfds) {
             nvhosts = get_fds(tap->vhostfds, vhost_fds, MAX_TAP_QUEUES);