From 0e8a4634d26eb2dbad659aa112f0b033ced576de Mon Sep 17 00:00:00 2001
Message-Id: <0e8a4634d26eb2dbad659aa112f0b033ced576de@dist-git>
From: Peter Krempa <pkrempa@redhat.com>
Date: Fri, 21 Nov 2014 15:04:05 +0100
Subject: [PATCH] util: storage: Copy hosts of a storage file only if they
 exist

https://bugzilla.redhat.com/show_bug.cgi?id=1164528

If there are no hosts for a storage source virStorageSourceCopy and
virStorageSourceNewFromBackingRelative would try to copy them anyways.
As the success of virStorageNetHostDefCopy is determined by returning
a pointer and malloc of 0 elements might return NULL according to the
implementation, the result of the copy function may vary.

Fix this by copying the hosts array only if there are hosts defined.

(cherry picked from commit c264ea58e9a34b7202d8041687621dfa68ad8750)

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/util/virstoragefile.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index d58f9ed..fa569d8 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -1845,9 +1845,12 @@ virStorageSourceCopy(const virStorageSource *src,
         VIR_STRDUP(ret->compat, src->compat) < 0)
         goto error;
 
-    if (!(ret->hosts = virStorageNetHostDefCopy(src->nhosts, src->hosts)))
-        goto error;
-    ret->nhosts = src->nhosts;
+    if (src->nhosts) {
+        if (!(ret->hosts = virStorageNetHostDefCopy(src->nhosts, src->hosts)))
+            goto error;
+
+        ret->nhosts = src->nhosts;
+    }
 
     if (src->srcpool &&
         !(ret->srcpool = virStorageSourcePoolDefCopy(src->srcpool)))
@@ -2071,9 +2074,13 @@ virStorageSourceNewFromBackingRelative(virStorageSourcePtr parent,
 
         /* copy the host network part */
         ret->protocol = parent->protocol;
-        if (!(ret->hosts = virStorageNetHostDefCopy(parent->nhosts, parent->hosts)))
-            goto error;
-        ret->nhosts = parent->nhosts;
+        if (parent->nhosts) {
+            if (!(ret->hosts = virStorageNetHostDefCopy(parent->nhosts,
+                                                        parent->hosts)))
+                goto error;
+
+            ret->nhosts = parent->nhosts;
+        }
 
         if (VIR_STRDUP(ret->volume, parent->volume) < 0)
             goto error;
-- 
2.1.3