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From:   Alexandru Matei <alexandru.matei@uipath.com>
To:     Stefan Hajnoczi <stefanha@redhat.com>,
        Stefano Garzarella <sgarzare@redhat.com>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Alexandru Matei <alexandru.matei@uipath.com>,
        Mihai Petrisor <mihai.petrisor@uipath.com>,
        Viorel Canja <viorel.canja@uipath.com>
Subject: [PATCH] vsock: initialize the_virtio_vsock before using VQs
Date:   Wed, 18 Oct 2023 21:32:47 +0300
Message-Id: <20231018183247.1827-1-alexandru.matei@uipath.com>
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Once VQs are filled with empty buffers and we kick the host, it can send
connection requests. If 'the_virtio_vsock' is not initialized before,
replies are silently dropped and do not reach the host.

Fixes: 0deab087b16a ("vsock/virtio: use RCU to avoid use-after-free on the_virtio_vsock")
Signed-off-by: Alexandru Matei <alexandru.matei@uipath.com>
---
 net/vmw_vsock/virtio_transport.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index e95df847176b..eae0867133f8 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -658,12 +658,13 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
 		vsock->seqpacket_allow = true;
 
 	vdev->priv = vsock;
+	rcu_assign_pointer(the_virtio_vsock, vsock);
 
 	ret = virtio_vsock_vqs_init(vsock);
-	if (ret < 0)
+	if (ret < 0) {
+		rcu_assign_pointer(the_virtio_vsock, NULL);
 		goto out;
-
-	rcu_assign_pointer(the_virtio_vsock, vsock);
+	}
 
 	mutex_unlock(&the_virtio_vsock_mutex);
 
-- 
2.34.1