The 'char control[CMSG_SPACE(sizeof(int))];' was not being wiped, so could potentially contain uninitialized bytes. While this was harmless in this case, it caused complaints from valgrind * src/qemu/qemu_monitor.c: memset 'control' variable in qemuMonitorIOWriteWithFD --- src/qemu/qemu_monitor.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index e995d97..8573262 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -383,6 +383,7 @@ qemuMonitorIOWriteWithFD(qemuMonitorPtr mon, struct cmsghdr *cmsg; memset(&msg, 0, sizeof(msg)); + memset(control, 0, sizeof(control)); iov[0].iov_base = (void *)data; iov[0].iov_len = len;