virsh: prevent potential NULL dereference

virXPathString() can return NULL so we need to use STRNEQ_NULLABLE here

Found by Linux Verification Center (linuxtesting.org) with Svace.

Reported-by: Dmitry Fedin <d.fedin@fobos-nt.ru>
Signed-off-by: Alexander Kuznetsov <kuznetsovam@altlinux.org>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/tools/virsh-completer-domain.c b/tools/virsh-completer-domain.c
index 0a3a113dcaf72eba1ae49f8eb5c8ad3eca50471c..b6a4d85ee8df2963346e09547cee37949c5be03e 100644 (file)
--- a/tools/virsh-completer-domain.c
+++ b/tools/virsh-completer-domain.c
@@ -891,7 +891,7 @@ virshDomainConsoleCompleter(vshControl *ctl,
             ctxt->node = parallels[i - nserials];
 
         type = virXPathString("string(./@type)", ctxt);
-        if (STRNEQ(type, "pty"))
+        if (STRNEQ_NULLABLE(type, "pty"))
             continue;
 
         tmp[offset++] = virXPathString("string(./alias/@name)", ctxt);