Re: [Qemu-devel] [PATCH 1/1] qom: fix qdict visit in user_creatable_add_type

2016-09-22 Thread Xiao Long Jiang 

Hi Markus,

On 2016/9/22 下午7:56, Markus Armbruster wrote:

Xiao Long Jiang  writes:


This fixes a Qemu crash that introduced by commit ad73970
("qom: Wrap prop visit in visit_start_struct").

Not all of the callers of user_creatable_add_type always pass qdict,
so we should check qdict against NULL, but not raise an assertion.

The problem can be easily triggered by adding an iothread with:
   $ virsh iothreadadd  
In which the  is newly defined. The result of the command
will return an error and cause the running guest crash.

Cc: Eric Blake 
Cc: Markus Armbruster 
Signed-off-by: Xiao Long Jiang 
Reviewed-by: Dong Jia Shi 

Marc-André already posted a simpler fix:
Subject: [PATCH] qmp: fix object-add assert() without props
Message-Id: <20160921194126.10223-1-marcandre.lur...@redhat.com>

Would you be willing to test it?  Review would of course also be
appreciated.

Thanks!


Have tested that patch. It works fine on arch s390 system.

Re: [Qemu-devel] [PATCH 1/1] qom: fix qdict visit in user_creatable_add_type

2016-09-22 Thread Markus Armbruster 
Xiao Long Jiang  writes:

> This fixes a Qemu crash that introduced by commit ad73970
> ("qom: Wrap prop visit in visit_start_struct").
>
> Not all of the callers of user_creatable_add_type always pass qdict,
> so we should check qdict against NULL, but not raise an assertion.
>
> The problem can be easily triggered by adding an iothread with:
>   $ virsh iothreadadd  
> In which the  is newly defined. The result of the command
> will return an error and cause the running guest crash.
>
> Cc: Eric Blake 
> Cc: Markus Armbruster 
> Signed-off-by: Xiao Long Jiang 
> Reviewed-by: Dong Jia Shi 

Marc-André already posted a simpler fix:
Subject: [PATCH] qmp: fix object-add assert() without props
Message-Id: <20160921194126.10223-1-marcandre.lur...@redhat.com>

Would you be willing to test it?  Review would of course also be
appreciated.

Thanks!

[Qemu-devel] [PATCH 1/1] qom: fix qdict visit in user_creatable_add_type

2016-09-22 Thread Xiao Long Jiang 
This fixes a Qemu crash that introduced by commit ad73970
("qom: Wrap prop visit in visit_start_struct").

Not all of the callers of user_creatable_add_type always pass qdict,
so we should check qdict against NULL, but not raise an assertion.

The problem can be easily triggered by adding an iothread with:
  $ virsh iothreadadd  
In which the  is newly defined. The result of the command
will return an error and cause the running guest crash.

Cc: Eric Blake 
Cc: Markus Armbruster 
Signed-off-by: Xiao Long Jiang 
Reviewed-by: Dong Jia Shi 
---
 qom/object_interfaces.c | 31 ---
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
index bf59846..cc40dff 100644
--- a/qom/object_interfaces.c
+++ b/qom/object_interfaces.c
@@ -112,24 +112,25 @@ Object *user_creatable_add_type(const char *type, const 
char *id,
 return NULL;
 }
 
-assert(qdict);
 obj = object_new(type);
-visit_start_struct(v, NULL, NULL, 0, &local_err);
-if (local_err) {
-goto out;
-}
-for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
-object_property_set(obj, v, e->key, &local_err);
+if (qdict) {
+visit_start_struct(v, NULL, NULL, 0, &local_err);
 if (local_err) {
-break;
+goto out;
+}
+for (e = qdict_first(qdict); e; e = qdict_next(qdict, e)) {
+object_property_set(obj, v, e->key, &local_err);
+if (local_err) {
+break;
+}
+}
+if (!local_err) {
+visit_check_struct(v, &local_err);
+}
+visit_end_struct(v, NULL);
+if (local_err) {
+goto out;
 }
-}
-if (!local_err) {
-visit_check_struct(v, &local_err);
-}
-visit_end_struct(v, NULL);
-if (local_err) {
-goto out;
 }
 
 object_property_add_child(object_get_objects_root(),
-- 
2.8.4