[Qemu-devel] [PATCH] qom: avoid leaking str and bool properties on failure

[Qemu-devel] [PATCH] qom: avoid leaking str and bool properties on failure

[Stefan Hajnoczi]

When object_property_add_str() and object_property_add_bool() fail, they
leak their internal StringProperty and BoolProperty structs.  Remember
to free the structs on error.

Luckily this is a low-impact memory leak since most QOM properties are
static qdev properties that will never take the error case.
object_property_add() only fails if the property name is already in use.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qom/object.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/qom/object.c b/qom/object.c
index 660859c..c88909c 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -1293,6 +1293,7 @@ void object_property_add_str(Object *obj, const char *name,
                            void (*set)(Object *, const char *, Error **),
                            Error **errp)
 {
+    Error *local_err = NULL;
     StringProperty *prop = g_malloc0(sizeof(*prop));
 
     prop->get = get;
@@ -1302,7 +1303,11 @@ void object_property_add_str(Object *obj, const char *name,
                         get ? property_get_str : NULL,
                         set ? property_set_str : NULL,
                         property_release_str,
-                        prop, errp);
+                        prop, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        g_free(prop);
+    }
 }
 
 typedef struct BoolProperty
@@ -1349,6 +1354,7 @@ void object_property_add_bool(Object *obj, const char *name,
                               void (*set)(Object *, bool, Error **),
                               Error **errp)
 {
+    Error *local_err = NULL;
     BoolProperty *prop = g_malloc0(sizeof(*prop));
 
     prop->get = get;
@@ -1358,7 +1364,11 @@ void object_property_add_bool(Object *obj, const char *name,
                         get ? property_get_bool : NULL,
                         set ? property_set_bool : NULL,
                         property_release_bool,
-                        prop, errp);
+                        prop, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        g_free(prop);
+    }
 }
 
 static char *qdev_get_type(Object *obj, Error **errp)
-- 
1.8.5.3

Re: [Qemu-devel] [PATCH] qom: avoid leaking str and bool properties on failure

[Eric Blake]

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On 03/04/2014 07:28 AM, Stefan Hajnoczi wrote:
> When object_property_add_str() and object_property_add_bool() fail, they
> leak their internal StringProperty and BoolProperty structs.  Remember
> to free the structs on error.
> 
> Luckily this is a low-impact memory leak since most QOM properties are
> static qdev properties that will never take the error case.
> object_property_add() only fails if the property name is already in use.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  qom/object.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH] qom: avoid leaking str and bool properties on failure

[Andreas Färber]

Am 04.03.2014 15:28, schrieb Stefan Hajnoczi:
> When object_property_add_str() and object_property_add_bool() fail, they
> leak their internal StringProperty and BoolProperty structs.  Remember
> to free the structs on error.
> 
> Luckily this is a low-impact memory leak since most QOM properties are
> static qdev properties that will never take the error case.
> object_property_add() only fails if the property name is already in use.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  qom/object.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)

Nice catch!

Thanks, applied to qom-next (and suggesting for qemu-stable):
https://github.com/afaerber/qemu-cpu/commits/qom-next

Regards,
Andreas

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