Re: [libvirt] [PATCH 2/2] Protect against NULL pointer flaws in monitor usage

History has shown that there are frequent bugs in the QEMU driver code leading to the monitor being invoked with a NULL pointer. Although the QEMU driver code should always report an error in this case before invoking the monitor, as a safety net put in a generic check in the monitor code entry points. * src/qemu/qemu_monitor.c: Safety net to check for NULL monitor object --- src/qemu/qemu_monitor.c | 409 +++++++++++++++++++++++++++++++++++++++------- 1 files changed, 346 insertions(+), 63 deletions(-) diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 2ce3d56..ec22c20 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -894,7 +894,13 @@ int qemuMonitorEmitGraphics(qemuMonitorPtr mon, int qemuMonitorSetCapabilities(qemuMonitorPtr mon) { int ret; - DEBUG("mon=%p, fd=%d", mon, mon->fd); + DEBUG("mon=%p", mon); + + if (!mon) { + qemuReportError(VIR_ERR_INVALID_ARG, "%s", + _("monitor must not be NULL")); + return -1; + }

@@ -1017,7 +1065,14 @@ int qemuMonitorSetVNCPassword(qemuMonitorPtr mon, const char *password) { int ret; - DEBUG("mon=%p, fd=%d", mon, mon->fd); + DEBUG("mon=%p, password=%p", + mon, password); + + if (!mon) { + qemuReportError(VIR_ERR_INVALID_ARG, "%s", + _("monitor must not be NULL")); + return -1; + }

if (!password) password = "";