qemu: Fix possible NULL deref in qemuDomainGetResctrlMonData

If virQEMUDriverGetCapabilities returns NULL, then a subsequent
deref of @caps would cause an error, so we just return failure.

Found by Coverity

Signed-off-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index f1983f33e60e30704a68ad8757f32374385c16b0..ff83d1c02420cd1dc966c36a4a13a5383739deb0 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -20728,7 +20728,8 @@ qemuDomainGetResctrlMonData(virQEMUDriverPtr driver,
     size_t i = 0;
     size_t j = 0;
 
-    caps = virQEMUDriverGetCapabilities(driver, false);
+    if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
+        return -1;
 
     switch (tag) {
     case VIR_RESCTRL_MONITOR_TYPE_CACHE: