Commit 466a8533 authored by Dexuan Cui's avatar Dexuan Cui Committed by Paolo Abeni
Browse files

vsock: fix possible infinite sleep in vsock_connectible_wait_data() 



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: b3f7fd54 ("af_vsock: separate wait data loop")
Signed-off-by: default avatarDexuan Cui <decui@microsoft.com>
Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Reported-by: default avatarFrédéric Dalleau <frederic.dalleau@docker.com>
Tested-by: default avatarFrédéric Dalleau <frederic.dalleau@docker.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent cf6ff0df

net/vmw_vsock/af_vsock.c

+4 −1
Original line number Diff line number Diff line
@@ -1905,8 +1905,11 @@ 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) ||