Re: [libvirt] [PATCH] qemu_monitor_json.c: avoid many unconditional leaks
Daniel P. Berrange wrote:
On Wed, Jan 27, 2010 at 11:17:32AM +0100, Jim Meyering wrote:
> Daniel P. Berrange wrote:
> > On Wed, Jan 27, 2010 at 10:38:55AM +0100, Jim Meyering wrote:
> >> Actually, the preceding patch fixed only the one leak that had been
> >> introduced in the last month or so. Looking at the many other functions
> >> that do the same sort of thing (call qemuMonitorJSONMakeCommand, and
> >> later virJSONValueFree), I saw that they all had exactly the same leak.
> >> So this amended patch fixes all of them:
> >>
> >> >From 28f820354dcae9950cad042ea78a893fd9475830 Mon Sep 17 00:00:00 2001
> >> From: Jim Meyering <meyering(a)redhat.com>
> >> Date: Wed, 27 Jan 2010 09:58:12 +0100
> >> Subject: [PATCH] qemu_monitor_json.c: avoid many unconditional leaks
> >
> > The real bug is the virJSONValueFree() itself which is missing
> > the final VIR_FREE(value) call. By doing the free in the caller, we
> > still leak data for compound array/hash values.
>
> Putting the VIR_FREE in virJSONValueFree was my first reflex, too,
> but since coverity detected no leak for the adjacent
> "virJSONValueFree(reply);" use, I assumed that doing so would
> cause a problem:
>
> virJSONValueFree(cmd);
> VIR_FREE(cmd);
> virJSONValueFree(reply);
I think coverity must be confused then :-) The virJSONValueFree() method
is definitely intended to free any memory allocated during one of the
virJSONValueNewXXXX() methods.
:-)
In that case, here's a replacement patch:
From 96196ca0b0cd71ae6b7f2dd7668432db95678e70 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering(a)redhat.com>
Date: Wed, 27 Jan 2010 09:58:12 +0100
Subject: [PATCH] json.c: avoid an unconditional leak from most qemuMonitorJSON* functions
* src/util/json.c (virJSONValueFree): Free the "value" pointer, too.
---
src/util/json.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/src/util/json.c b/src/util/json.c
index a292e1b..1b3c359 100644
--- a/src/util/json.c
+++ b/src/util/json.c
@@ -2,7 +2,7 @@
* json.c: JSON object parsing/formatting
*
* Copyright (C) 2009 Daniel P. Berrange
- * Copyright (C) 2009 Red Hat, Inc.
+ * Copyright (C) 2009-2010 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -82,8 +82,9 @@ void virJSONValueFree(virJSONValuePtr value)
case VIR_JSON_TYPE_NUMBER:
VIR_FREE(value->data.number);
break;
-
}
+
+ VIR_FREE(value);
}
--
1.7.0.rc0.140.gfbe7