On Mon, Oct 23, 2023 at 05:59:45PM +0300, Alexandru Matei wrote:
On 10/23/2023 5:52 PM, Alexandru Matei wrote:
On 10/23/2023 5:29 PM, Stefano Garzarella wrote:
On Mon, Oct 23, 2023 at 05:08:33PM +0300, 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>
---
v2:
- split virtio_vsock_vqs_init in vqs_init and vqs_fill and moved
the_virtio_vsock initialization after vqs_init
net/vmw_vsock/virtio_transport.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index e95df847176b..92738d1697c1 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -559,6 +559,11 @@ static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
vsock->tx_run = true;
mutex_unlock(&vsock->tx_lock);
+ return 0;
+}
+
+static void virtio_vsock_vqs_fill(struct virtio_vsock *vsock)
What about renaming this function in virtio_vsock_vqs_start() and move also the setting of `tx_run` here?
It works but in this case we also need to move rcu_assign_pointer in virtio_vsock_vqs_start(),
the assignment needs to be right after setting tx_run to true and before filling the VQs.
Why?
If `rx_run` is false, we shouldn't need to send replies to the host
IIUC.
If we need this instead, please add a comment in the code, but also in
the commit, because it's not clear why.
And if we move rcu_assign_pointer then there is no need to split the function in two,
We can move rcu_assign_pointer() directly inside virtio_vsock_vqs_init() after setting tx_run.
Yep, this could be another option, but we need to change the name of
that function in this case.
Stefano
Thanks,
Stefano
+{
mutex_lock(&vsock->rx_lock);
virtio_vsock_rx_fill(vsock);
vsock->rx_run = true;
@@ -568,8 +573,6 @@ static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
virtio_vsock_event_fill(vsock);
vsock->event_run = true;
mutex_unlock(&vsock->event_lock);
-
- return 0;
}
static void virtio_vsock_vqs_del(struct virtio_vsock *vsock)
@@ -664,6 +667,7 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
goto out;
rcu_assign_pointer(the_virtio_vsock, vsock);
+ virtio_vsock_vqs_fill(vsock);
mutex_unlock(&the_virtio_vsock_mutex);
@@ -736,6 +740,7 @@ static int virtio_vsock_restore(struct virtio_device *vdev)
goto out;
rcu_assign_pointer(the_virtio_vsock, vsock);
+ virtio_vsock_vqs_fill(vsock);
out:
mutex_unlock(&the_virtio_vsock_mutex);
--
2.34.1
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