File io-remove-io-watch-if-TLS-channel-is-clo.patch of Package qemu.30221

From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Tue, 20 Jun 2023 09:45:34 +0100
Subject: io: remove io watch if TLS channel is closed during handshake
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Git-commit: 10be627d2b5ec2d6b3dce045144aa739eef678b4
References: bsc#1212850 (CVE-2023-3354)

The TLS handshake make take some time to complete, during which time an
I/O watch might be registered with the main loop. If the owner of the
I/O channel invokes qio_channel_close() while the handshake is waiting
to continue the I/O watch must be removed. Failing to remove it will
later trigger the completion callback which the owner is not expecting
to receive. In the case of the VNC server, this results in a SEGV as
vnc_disconnect_start() tries to shutdown a client connection that is
already gone / NULL.

CVE-2023-3354
Reported-by: jiangyegen <jiangyegen@huawei.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com
DF: Open-code g_clear_handle_id(), as it's not available in glib
    until version 2.56.
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
---
 include/io/channel-tls.h |  1 +
 io/channel-tls.c         | 19 +++++++++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/include/io/channel-tls.h b/include/io/channel-tls.h
index fdbdf12feb1e73b020190d186754..e49e2831a2607e6bf992877e4661 100644
--- a/include/io/channel-tls.h
+++ b/include/io/channel-tls.h
@@ -49,6 +49,7 @@ struct QIOChannelTLS {
     QIOChannel *master;
     QCryptoTLSSession *session;
     QIOChannelShutdown shutdown;
+    guint hs_ioc_tag;
 };
 
 /**
diff --git a/io/channel-tls.c b/io/channel-tls.c
index 7ec8ceff2f01744080126985c101..ce1247f8153d92f155e719d89626 100644
--- a/io/channel-tls.c
+++ b/io/channel-tls.c
@@ -194,12 +194,13 @@ static void qio_channel_tls_handshake_task(QIOChannelTLS *ioc,
         }
 
         trace_qio_channel_tls_handshake_pending(ioc, status);
-        qio_channel_add_watch_full(ioc->master,
-                                   condition,
-                                   qio_channel_tls_handshake_io,
-                                   data,
-                                   NULL,
-                                   context);
+        ioc->hs_ioc_tag =
+            qio_channel_add_watch_full(ioc->master,
+                                       condition,
+                                       qio_channel_tls_handshake_io,
+                                       data,
+                                       NULL,
+                                       context);
     }
 }
 
@@ -214,6 +215,7 @@ static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(
         qio_task_get_source(task));
 
+    tioc->hs_ioc_tag = 0;
     g_free(data);
     qio_channel_tls_handshake_task(tioc, task, context);
 
@@ -371,6 +373,11 @@ static int qio_channel_tls_close(QIOChannel *ioc,
 {
     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
 
+    if (tioc->hs_ioc_tag > 0) {
+        g_source_remove(tioc->hs_ioc_tag);
+        tioc->hs_ioc_tag = 0;
+    }
+
     return qio_channel_close(tioc->master, errp);
 }