[libvirt] [PATCH 4/4] qemu: Obtain reference on monConfig
Because we allow a QEMU_JOB_DESTROY to occur while we're starting
up and we drop the @vm lock prior to qemuMonitorOpen, it's possible
that a domain destroy operation "wins" the race, calls qemuProcessStop
which will free and reinitialize priv->monConfig. Depending on the
exact timing either qemuMonitorOpen will be passed a NULL @config
variable or it will be using free'd (and possibly reclaimed) memory
as the @config parameter - neither of which is good.
Resolve this by localizing the @monConfig, taking an extra reference,
and then once we get the @vm lock again removing our reference since
we are done with it.
Signed-off-by: John Ferlan <jferlan(a)redhat.com>
---
src/qemu/qemu_process.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index a8dab92dd6..988c6b1537 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -1776,6 +1776,7 @@ qemuConnectMonitor(virQEMUDriverPtr driver, virDomainObjPtr vm, int
asyncJob,
qemuDomainObjPrivatePtr priv = vm->privateData;
qemuMonitorPtr mon = NULL;
unsigned long long timeout = 0;
+ virDomainChrSourceDefPtr monConfig;
if (qemuSecuritySetDaemonSocketLabel(driver->securityManager, vm->def) < 0)
{
VIR_ERROR(_("Failed to set security context for monitor for %s"),
@@ -1794,10 +1795,12 @@ qemuConnectMonitor(virQEMUDriverPtr driver, virDomainObjPtr vm,
int asyncJob,
virObjectRef(vm);
ignore_value(virTimeMillisNow(&priv->monStart));
+ monConfig = priv->monConfig;
+ virObjectRef(monConfig);
virObjectUnlock(vm);
mon = qemuMonitorOpen(vm,
- priv->monConfig,
+ monConfig,
priv->monJSON,
timeout,
&monitorCallbacks,
@@ -1813,6 +1816,7 @@ qemuConnectMonitor(virQEMUDriverPtr driver, virDomainObjPtr vm, int
asyncJob,
virObjectLock(vm);
virObjectUnref(vm);
+ virObjectUnref(monConfig);
priv->monStart = 0;
if (!virDomainObjIsActive(vm)) {
--
2.13.6