[libvirt] [PATCH] lock qemu_driver early in qemuGetSchedulerParametersFlags()

[Wen Congyang]

If we pass VIR_DOMAIN_AFFECT_LIVE | VIR_DOMAIN_AFFECT_CONFIG to
qemuGetSchedulerParametersFlags() or *nparams is less than 1,
we will unlock qemu_driver without locking it. It's very dangerous.

We should lock qemu_driver after calling virCheckFlags().

---
 src/qemu/qemu_driver.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 768e0f2..c6994cd 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -5832,6 +5832,8 @@ qemuGetSchedulerParametersFlags(virDomainPtr dom,
     virCheckFlags(VIR_DOMAIN_AFFECT_LIVE |
                   VIR_DOMAIN_AFFECT_CONFIG, -1);
 
+    qemuDriverLock(driver);
+
     if ((flags & (VIR_DOMAIN_AFFECT_LIVE | VIR_DOMAIN_AFFECT_CONFIG)) ==
         (VIR_DOMAIN_AFFECT_LIVE | VIR_DOMAIN_AFFECT_CONFIG)) {
         qemuReportError(VIR_ERR_INVALID_ARG, "%s",
@@ -5845,7 +5847,6 @@ qemuGetSchedulerParametersFlags(virDomainPtr dom,
         goto cleanup;
     }
 
-    qemuDriverLock(driver);
     vm = virDomainFindByUUID(&driver->domains, dom->uuid);
 
     if (vm == NULL) {
-- 
1.7.1