qemu: Don't crash when getting targets for a multipath

In one of my previous commits I've introduced code that creates
all devices for given (possible) multipath target. But I've made
a mistake there - the code accesses 'next->path' without checking
if the disk source is local. Note that the 'next->path' is
NULL/doesn't make sense for VIR_STORAGE_TYPE_NVME.

Fixes: a30078cb832646177defd256e77c632905f1e6d0
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1814947

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 0e2252f6cf2c4a5cef97b07c52263ac33372b4ba..6b70f457ca175f7faefda103630236c9b9011e9f 100644 (file)
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -15846,7 +15846,6 @@ qemuDomainNamespaceSetupDisk(virDomainObjPtr vm,
     bool hasNVMe = false;
 
     for (next = src; virStorageSourceIsBacking(next); next = next->backingStore) {
-        VIR_AUTOSTRINGLIST targetPaths = NULL;
         g_autofree char *tmpPath = NULL;
 
         if (next->type == VIR_STORAGE_TYPE_NVME) {
@@ -15855,6 +15854,8 @@ qemuDomainNamespaceSetupDisk(virDomainObjPtr vm,
             if (!(tmpPath = virPCIDeviceAddressGetIOMMUGroupDev(&next->nvme->pciAddr)))
                 return -1;
         } else {
+            VIR_AUTOSTRINGLIST targetPaths = NULL;
+
             if (virStorageSourceIsEmpty(next) ||
                 !virStorageSourceIsLocalStorage(next)) {
                 /* Not creating device. Just continue. */
@@ -15862,20 +15863,20 @@ qemuDomainNamespaceSetupDisk(virDomainObjPtr vm,
             }
 
             tmpPath = g_strdup(next->path);
-        }
 
-        if (virStringListAdd(&paths, tmpPath) < 0)
-            return -1;
+            if (virDevMapperGetTargets(next->path, &targetPaths) < 0 &&
+                errno != ENOSYS && errno != EBADF) {
+                virReportSystemError(errno,
+                                     _("Unable to get devmapper targets for %s"),
+                                     next->path);
+                return -1;
+            }
 
-        if (virDevMapperGetTargets(next->path, &targetPaths) < 0 &&
-            errno != ENOSYS && errno != EBADF) {
-            virReportSystemError(errno,
-                                 _("Unable to get devmapper targets for %s"),
-                                 next->path);
-            return -1;
+            if (virStringListMerge(&paths, &targetPaths) < 0)
+                return -1;
         }
 
-        if (virStringListMerge(&paths, &targetPaths) < 0)
+        if (virStringListAdd(&paths, tmpPath) < 0)
             return -1;
     }