From e8ffa273684efa5de18fad0913d6da4a93a9682d Mon Sep 17 00:00:00 2001
Message-Id: <e8ffa273684efa5de18fad0913d6da4a93a9682d@dist-git>
From: Martin Kletzander <mkletzan@redhat.com>
Date: Thu, 13 Aug 2015 15:11:45 +0200
Subject: [PATCH] qemu: Fix segfault when parsing private domain data

https://bugzilla.redhat.com/show_bug.cgi?id=1162947

When parsing private domain data, there are two paths that are flawed.
They are both error paths, just from different parts of the function.
One of them can call free() on an uninitialized pointer.  Initialization
to NULL is enough here.  The other one is a bit trickier to explain, but
as easy as the first one to fix.  We create capabilities, parse them and
then assign them into the private data pointer inside the domain object.
If, however, we get to fail from now on, the error path calls unrefs the
capabilities and then, when the domain object is being cleaned,
qemuDomainObjPrivateFree() tries to unref them as well.  That causes a
segfault.  Settin the pointer to NULL upon successful addition to the
private data is enough.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
(cherry picked from commit 92ddffdbd3c91d99f8f7ed9b661388a2c5d36cc2)
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/qemu/qemu_domain.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index c247737..d95f24f 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -627,7 +627,7 @@ qemuDomainObjPrivateXMLParse(xmlXPathContextPtr ctxt,
 {
     qemuDomainObjPrivatePtr priv = vm->privateData;
     char *monitorpath;
-    char *tmp;
+    char *tmp = NULL;
     int n;
     size_t i;
     xmlNodePtr *nodes = NULL;
@@ -715,6 +715,7 @@ qemuDomainObjPrivateXMLParse(xmlXPathContextPtr ctxt,
         }
 
         priv->qemuCaps = qemuCaps;
+        qemuCaps = NULL;
     }
     VIR_FREE(nodes);
 
-- 
2.5.0