From d153d468c43d67ebd86e4a7227c5de434749ecd3 Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Mon, 31 Oct 2022 19:17:06 -0700 Subject: [PATCH] vsock: fix possible infinite sleep in vsock_connectible_wait_data() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ 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 Reviewed-by: Stefano Garzarella Reported-by: Frédéric Dalleau Tested-by: Frédéric Dalleau Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- 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 5d46036f3ad7..dc36a46ce0e7 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1897,8 +1897,11 @@ 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) ||