qemu-char: avoid leaking unused fds in tcp_get_msgfds()

Commit c76bf6bb8fbbb233a7d3641e09229d23747d5ee3 ("Add chardev API
qemu_chr_fe_get_msgfds") extended the get_msgfds API from one to
multiple file descriptors.  It forgot to close unused file descriptors
before freeing the file descriptor array.

This patch prevents a file descriptor leak if the tcp_get_msgfds()
callers requests fewer file descriptors than are available.

Cc: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/qemu-char.c b/qemu-char.c
index d9100a2201..e6cbafb09c 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2481,8 +2481,15 @@ static int tcp_get_msgfds(CharDriverState *chr, int *fds, int num)
     int to_copy = (s->read_msgfds_num < num) ? s->read_msgfds_num : num;
 
     if (to_copy) {
+        int i;
+
         memcpy(fds, s->read_msgfds, to_copy * sizeof(int));
 
+        /* Close unused fds */
+        for (i = to_copy; i < s->read_msgfds_num; i++) {
+            close(s->read_msgfds[i]);
+        }
+
         g_free(s->read_msgfds);
         s->read_msgfds = 0;
         s->read_msgfds_num = 0;