The client's sk_state will be set to TCP_ESTABLISHED if the server
replay the client's connect request.
However, if the client has pending signal, its sk_state will be set
to TCP_CLOSE without notify the server, so the server will hold the
corrupt connection.
client server
1. sk_state=TCP_SYN_SENT |
2. call ->connect() |
3. wait reply |
| 4. sk_state=TCP_ESTABLISHED
| 5. insert to connected list
| 6. reply to the client
7. sk_state=TCP_ESTABLISHED |
8. insert to connected list |
9. *signal pending* <--------------------- the user kill client
10. sk_state=TCP_CLOSE |
client is exiting... |
11. call ->release() |
virtio_transport_close
if (!(sk->sk_state == TCP_ESTABLISHED ||
sk->sk_state == TCP_CLOSING))
return true; *return at here, the server cannot notice the connection is corrupt*
So the client should notify the peer in this case.
Cc: David S. Miller <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Jorgen Hansen <[email protected]>
Cc: Norbert Slusarek <[email protected]>
Cc: Andra Paraschiv <[email protected]>
Cc: Colin Ian King <[email protected]>
Cc: David Brazdil <[email protected]>
Cc: Alexander Popov <[email protected]>
Suggested-by: Stefano Garzarella <[email protected]>
Link: https://lkml.org/lkml/2021/5/17/418
Signed-off-by: lixianming <[email protected]>
Signed-off-by: Longpeng(Mike) <[email protected]>
---
net/vmw_vsock/af_vsock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 92a72f0..ae11311 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1369,7 +1369,7 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
if (signal_pending(current)) {
err = sock_intr_errno(timeout);
- sk->sk_state = TCP_CLOSE;
+ sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
sock->state = SS_UNCONNECTED;
vsock_transport_cancel_pkt(vsk);
goto out_wait;
--
1.8.3.1
On Mon, Jun 21, 2021 at 02:26:01PM +0800, Longpeng(Mike) wrote:
>The client's sk_state will be set to TCP_ESTABLISHED if the server
>replay the client's connect request.
>
>However, if the client has pending signal, its sk_state will be set
>to TCP_CLOSE without notify the server, so the server will hold the
>corrupt connection.
>
> client server
>
>1. sk_state=TCP_SYN_SENT |
>2. call ->connect() |
>3. wait reply |
> | 4. sk_state=TCP_ESTABLISHED
> | 5. insert to connected list
> | 6. reply to the client
>7. sk_state=TCP_ESTABLISHED |
>8. insert to connected list |
>9. *signal pending* <--------------------- the user kill client
>10. sk_state=TCP_CLOSE |
>client is exiting... |
>11. call ->release() |
> virtio_transport_close
> if (!(sk->sk_state == TCP_ESTABLISHED ||
> sk->sk_state == TCP_CLOSING))
> return true; *return at here, the server cannot notice the connection is corrupt*
>
>So the client should notify the peer in this case.
>
>Cc: David S. Miller <[email protected]>
>Cc: Jakub Kicinski <[email protected]>
>Cc: Jorgen Hansen <[email protected]>
>Cc: Norbert Slusarek <[email protected]>
>Cc: Andra Paraschiv <[email protected]>
>Cc: Colin Ian King <[email protected]>
>Cc: David Brazdil <[email protected]>
>Cc: Alexander Popov <[email protected]>
>Suggested-by: Stefano Garzarella <[email protected]>
>Link: https://lkml.org/lkml/2021/5/17/418
>Signed-off-by: lixianming <[email protected]>
>Signed-off-by: Longpeng(Mike) <[email protected]>
>---
> net/vmw_vsock/af_vsock.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index 92a72f0..ae11311 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -1369,7 +1369,7 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
>
> if (signal_pending(current)) {
> err = sock_intr_errno(timeout);
>- sk->sk_state = TCP_CLOSE;
>+ sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE;
> sock->state = SS_UNCONNECTED;
> vsock_transport_cancel_pkt(vsk);
> goto out_wait;
>--
>1.8.3.1
>
Reviewed-by: Stefano Garzarella <[email protected]>
Hello:
This patch was applied to netdev/net.git (refs/heads/master):
On Mon, 21 Jun 2021 14:26:01 +0800 you wrote:
> The client's sk_state will be set to TCP_ESTABLISHED if the server
> replay the client's connect request.
>
> However, if the client has pending signal, its sk_state will be set
> to TCP_CLOSE without notify the server, so the server will hold the
> corrupt connection.
>
> [...]
Here is the summary with links:
- [v2] vsock: notify server to shutdown when client has pending signal
https://git.kernel.org/netdev/net/c/c7ff9cff7060
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html