File libvirt-qemu_agent-Remove-agent-reference-only-when-disposing-it.patch of Package libvirt

From 142100965a9d466523b74755418c261fe64cec33 Mon Sep 17 00:00:00 2001
Message-Id: <142100965a9d466523b74755418c261fe64cec33.1358348559.git.jdenemar@redhat.com>
From: Michal Privoznik <mprivozn@redhat.com>
Date: Thu, 10 Jan 2013 11:02:34 +0100
Subject: [PATCH] qemu_agent: Remove agent reference only when disposing it

https://bugzilla.redhat.com/show_bug.cgi?id=892079

With current code, if user calls virDomainPMSuspendForDuration()
followed by virDomainDestroy(), the former API checks for qemu agent
presence, which will evaluate as true (if agent is configured). While
talking to qemu agent, the qemu driver is unlocked, so the latter API
starts executing.  However, if machine dies meanwhile, libvirtd gets
EOF on the agent socket and qemuProcessHandleAgentEOF() is called. The
handler clears reference to qemu agent while the destroy API already
holding a reference to it. This leads to NULL dereferencing later in
the code. Therefore, the agent pointer should be set to NULL only if
we are the exclusive owner of it.
(cherry picked from commit f2a4e5f176c408fd2db79ed08b2a7d32a52d35a2)
---
 src/qemu/qemu_process.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 91369c7..3ca315e 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -128,7 +128,8 @@ qemuProcessHandleAgentEOF(qemuAgentPtr agent,
     virDomainObjLock(vm);
 
     priv = vm->privateData;
-    if (priv->agent == agent)
+    if (priv->agent == agent &&
+        !virObjectUnref(priv->agent))
         priv->agent = NULL;
 
     virDomainObjUnlock(vm);
-- 
1.8.1.1