[PATCH] vsock: initialize the_virtio_vsock before using VQs

From: Alexandru Matei
Date: Wed Oct 18 2023 - 14:33:38 EST


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@xxxxxxxxxx>
---
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