On 18/10/2023 19:32, Alexandru Matei wrote:
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);
Looks like virtio_vsock_restore() needs the same changes. But
virtio_vsock_vqs_init() can fail only in virtio_find_vqs(). Maybe it can
be split into 2 functions to avoid second rcu_assign_pointer() in case
of error?
