[libvirt] [PATCH] qemu: Prevent crash of libvirtd when setting numa parameters

[ajia at redhat.com]

From: Alex Jia <ajia at redhat.com>

It's a NULL pointer deref issue, which leads to libvirtd crash. This patch 
directly use 'params[i].value.s' value instead of derefing a NULL pointer
on memcpy.

* how to reproduce?
% virsh numatune <domain> --nodeset 0
% service libvirtd status

* src/qemu/qemu_driver.c (qemuDomainSetNumaParameters): avoid a NULL pointer deref.

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=771562

Signed-off-by: Alex Jia <ajia at redhat.com>
---
 src/qemu/qemu_driver.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 82bab67..1bd93f6 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -6721,14 +6721,12 @@ qemuDomainSetNumaParameters(virDomainPtr dom,
             }
 
             if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
-                memcpy(oldnodemask, persistentDef->numatune.memory.nodemask,
-                       VIR_DOMAIN_CPUMASK_LEN);
+                memcpy(oldnodemask, params[i].value.s, VIR_DOMAIN_CPUMASK_LEN);
                 if (virDomainCpuSetParse(params[i].value.s,
                                          0,
                                          persistentDef->numatune.memory.nodemask,
                                          VIR_DOMAIN_CPUMASK_LEN) < 0) {
-                    memcpy(persistentDef->numatune.memory.nodemask,
-                           oldnodemask, VIR_DOMAIN_CPUMASK_LEN);
+                    memcpy(params[i].value.s, oldnodemask, VIR_DOMAIN_CPUMASK_LEN);
                     ret = -1;
                     continue;
                 }
-- 
1.7.1