[libvirt PATCH] remote: add mutex when freeing private callbacks

[Martin Kletzander]

On Mon, Mar 06, 2023 at 06:35:44PM +0000, Mike Pontillo wrote:
>This commit resolves illegal memory accesses observed via:
>
>  remoteClientFreePrivateCallbacks()
>  remoteClientCloseFunc()
>  virNetServerClientCloseLocked()
>  virNetServerProcessClients()
>  daemonServerProcessClients()
>  virHashForEach()
>  virNetDaemonRun()
>  main()
>
>Signed-off-by: Mike Pontillo <mpontillo at digitalocean.com>
>---
> src/remote/remote_daemon_dispatch.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
>diff --git a/src/remote/remote_daemon_dispatch.c b/src/remote/remote_daemon_dispatch.c
>index 250eb51e6b..8d043d0bce 100644
>--- a/src/remote/remote_daemon_dispatch.c
>+++ b/src/remote/remote_daemon_dispatch.c
>@@ -1711,6 +1711,8 @@ remoteClientFreePrivateCallbacks(struct daemonClientPrivate *priv)
>     g_autoptr(virIdentity) sysident = virIdentityGetSystem();
>     virIdentitySetCurrent(sysident);
>
>+    virMutexLock(&priv->lock);
>+

Good catch, we can make it even slicker with:

   VIR_LOCK_GUARD lock = virLockGuardLock(&priv->lock);

and rely on automatic unlock at the return.  Either way (let me know if
you're OK with the proposed change):

Reviewed-by: Martin Kletzander <mkletzan at redhat.com>

and I'll wait a bit for your answer before pushing.

>     DEREG_CB(priv->conn, priv->domainEventCallbacks,
>              priv->ndomainEventCallbacks,
>              virConnectDomainEventDeregisterAny, "domain");
>@@ -1737,6 +1739,8 @@ remoteClientFreePrivateCallbacks(struct daemonClientPrivate *priv)
>     }
>
>     virIdentitySetCurrent(NULL);
>+
>+    virMutexUnlock(&priv->lock);
> }
> #undef DEREG_CB
>
>-- 
>2.34.1
>
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