From: Dexuan Cui decui@microsoft.com
[ Upstream commit 466a85336fee6e3b35eb97b8405a28302fd25809 ]
Currently vsock_connectible_has_data() may miss a wakeup operation between vsock_connectible_has_data() == 0 and the prepare_to_wait().
Fix the race by adding the process to the wait queue before checking vsock_connectible_has_data().
Fixes: b3f7fd54881b ("af_vsock: separate wait data loop") Signed-off-by: Dexuan Cui decui@microsoft.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Reported-by: Frédéric Dalleau frederic.dalleau@docker.com Tested-by: Frédéric Dalleau frederic.dalleau@docker.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/vmw_vsock/af_vsock.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index b4ee163154a6..e5ab2418f9d6 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1894,8 +1894,11 @@ static int vsock_connectible_wait_data(struct sock *sk, err = 0; transport = vsk->transport;
- while ((data = vsock_connectible_has_data(vsk)) == 0) { + while (1) { prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE); + data = vsock_connectible_has_data(vsk); + if (data != 0) + break;
if (sk->sk_err != 0 || (sk->sk_shutdown & RCV_SHUTDOWN) ||