From 0306736e3afbe7be99d01e4d70d1a5f2e38c32c2 Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Tue, 15 Aug 2023 00:08:55 +0000
Subject: [PATCH] io: remove io watch if TLS channel is closed during handshake
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RH-Author: Jon Maloy <jmaloy@redhat.com>
RH-MergeRequest: 315: io: remove io watch if TLS channel is closed during handshake
RH-Bugzilla: 2216504
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [1/1] 5f23602074b2edde0d445d529f07434bd156202d (redhat/rhel/src/qemu-kvm/jons-qemu-kvm-2)

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2216504
CVE: CVE-2023-3354
Upstream: Merged

commit 10be627d2b5ec2d6b3dce045144aa739eef678b4
Author: Daniel P. Berrangé <berrange@redhat.com>
Date:   Tue Jun 20 09:45:34 2023 +0100

    io: remove io watch if TLS channel is closed during handshake

    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>

Signed-off-by: Jon Maloy <jmaloy@redhat.com>
---
 include/io/channel-tls.h |  1 +
 io/channel-tls.c         | 18 ++++++++++++------
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/include/io/channel-tls.h b/include/io/channel-tls.h
index 5672479e9e..26c67f17e2 100644
--- a/include/io/channel-tls.h
+++ b/include/io/channel-tls.h
@@ -48,6 +48,7 @@ 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 9805dd0a3f..847d5297c3 100644
--- a/io/channel-tls.c
+++ b/io/channel-tls.c
@@ -198,12 +198,13 @@ 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);
     }
 }
 
@@ -218,6 +219,7 @@ 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);
 
@@ -378,6 +380,10 @@ static int qio_channel_tls_close(QIOChannel *ioc,
 {
     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
 
+    if (tioc->hs_ioc_tag) {
+        g_clear_handle_id(&tioc->hs_ioc_tag, g_source_remove);
+    }
+
     return qio_channel_close(tioc->master, errp);
 }
 
-- 
2.39.3