Re: [PATCH] remote/stream-event: Fix a memory leak in?? remoteStreamCallbackFree()
[+to libvirt development list, since this looks like a libvirt patch,
not a Linux kernel patch]
On Thu, Jun 26, 2025 at 02:10:38PM +0800, liu.xuemei1(a)zte.com.cn wrote:
> From: Liu Song <liu.song13(a)zte.com.cn>
>
> The ff callback is never called in remoteStreamCallbackFree() because
> cbdata->cb can not be NULL. This causes a leak of 'cbdata->opaque'.
>
> The leak can be reproduced by attaching and detaching to the console of
> an VM using `virsh console`.
>
> ASAN reports the leak stack as:
> Direct leak of 288 byte(s) in 1 object(s) allocated from:
> #0 0x7f6edf6ba0c7 in calloc (/lib64/libasan.so.8+0xba0c7)
> #1 0x7f6edf5175b0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x615b0)
> #2 0x7f6ede6d0be3 in g_type_create_instance (/lib64/libgobject-2.0.so.0+0x3cbe3)
> #3 0x7f6ede6b82cf in g_object_new_internal (/lib64/libgobject-2.0.so.0+0x242cf)
> #4 0x7f6ede6b9877 in g_object_new_with_properties
(/lib64/libgobject-2.0.so.0+0x25877)
> #5 0x7f6ede6ba620 in g_object_new (/lib64/libgobject-2.0.so.0+0x26620)
> #6 0x7f6edeb78138 in virObjectNew ../src/util/virobject.c:252
> #7 0x7f6edeb7a78b in virObjectLockableNew ../src/util/virobject.c:274
> #8 0x558251e427e1 in virConsoleNew ../tools/virsh-console.c:369
> #9 0x558251e427e1 in virshRunConsole ../tools/virsh-console.c:427
>
> Signed-off-by: Liu Song <liu.song13(a)zte.com.cn>
> ---
> src/remote/remote_daemon_stream.c | 2 +-
> src/remote/remote_driver.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/src/remote/remote_daemon_stream.c b/src/remote/remote_daemon_stream.c
> index 453728a66b..a5032f9a43 100644
> --- a/src/remote/remote_daemon_stream.c
> +++ b/src/remote/remote_daemon_stream.c
> @@ -437,13 +437,13 @@ int daemonAddClientStream(virNetServerClient *client,
> return -1;
> }
>
> + virObjectRef(client);
> if (virStreamEventAddCallback(stream->st, 0,
> daemonStreamEvent, client,
> virObjectUnref) < 0)
> return -1;
>
> virObjectRef(client);
> -
> if ((stream->filterID = virNetServerClientAddFilter(client,
> daemonStreamFilter,
> stream)) < 0) {
> diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
> index 2690c05267..9ac13469e9 100644
> --- a/src/remote/remote_driver.c
> +++ b/src/remote/remote_driver.c
> @@ -5336,7 +5336,7 @@ static void remoteStreamCallbackFree(void *opaque)
> {
> struct remoteStreamCallbackData *cbdata = opaque;
>
> - if (!cbdata->cb && cbdata->ff)
> + if (cbdata->ff)
> (cbdata->ff)(cbdata->opaque);
>
> virObjectUnref(cbdata->st);
> --
> 2.27.0