[PATCH] qemu: Fix crash in qemuBuildDeviceCommandlineHandleOverrides

[Peter Krempa]

'STREQ' is used to compare the override alias with the device alias.
While the parser ensures that the override alias is non-NULL, the device
alias may be NULL and STREQ doesn't handle that.

Fixes: 38ab5c9ead5
Resolves: https://gitlab.com/libvirt/libvirt/-/issues/321
Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/qemu/qemu_command.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 52e4ef03cd..b1be77743c 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -240,6 +240,10 @@ qemuBuildDeviceCommandlineHandleOverrides(virJSONValue *props,
     const char *alias = virJSONValueObjectGetString(props, "id");
     size_t i;

+    /* If the device doesn't have an alias we can't override it's props */
+    if (!alias)
+        return;
+
     for (i = 0; i < nsdef->ndeviceOverride; i++) {
         qemuDomainXmlNsDeviceOverride *dev = nsdef->deviceOverride + i;
         size_t j;
-- 
2.36.1