[libvirt] [PATCH v2 1/2] daemon: Fix segfault by reloading daemon right after start

Libvirt could crash with segfault if user issue "service reload" right after "service start". One possible way to crash libvirt is to run reload during initialization of QEMU driver. It could happen when qemu driver will initialize qemu_driver_lock but don't have a time to set it's "config" and the SIGHUP arrives. The reload handler tries to get qemu_drv->config during "virStorageAutostart" and dereference it which ends with segfault. Let's ignore all reload requests until all drivers are initialized. In addition set "driversInitialized" before we enter "virStateCleanup" to ignore reload request while we are shutting down. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1179981 Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; --- diff to v1: - ignore reload also during virStateCleanup daemon/libvirtd.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c index 86accaa..2366d63 100644 --- a/daemon/libvirtd.c +++ b/daemon/libvirtd.c @@ -785,6 +785,11 @@ static void daemonReloadHandler(virNetServerPtr srv ATTRIBUTE_UNUSED, siginfo_t *sig ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED) { + if (!driversInitialized) { + VIR_WARN("Drivers are not initialized, reload ignored"); + return; + } + VIR_INFO("Reloading configuration on SIGHUP"); virHookCall(VIR_HOOK_DRIVER_DAEMON, "-", VIR_HOOK_DAEMON_OP_RELOAD, SIGHUP, "SIGHUP", NULL, NULL); @@ -1519,8 +1524,10 @@ int main(int argc, char **argv) { daemonConfigFree(config); - if (driversInitialized) + if (driversInitialized) { + driversInitialized = false; virStateCleanup(); + } return ret; } -- 2.0.5